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Contamination Question Answering

A large waterborne outbreak of NoV occurred in Lilla Edet in Sweden in 2008. On 11 September 2008, the County Medical Ofcer (CMO) was informed about an unusually high number of individuals who had suddenly fallen ill with gastrointestinal symptoms during the previous days in Lilla Edet, a small municipality in southwest Sweden. Cases of gastroenteritis were reported from different places in the municipality, e.g. from the nursery schools, schools, nursing homes and from the Primary Healthcare Centre (PHC). The CMO notified the Environmental Office in the municipality about the ongoing outbreak. As the initial information indicated that drinking water was a possible source of the outbreak a boil water recommendation was issued on the same day. Investigations were initiated to identify the causative agents, the extent of the outbreak and possible sources of infection. Efforts were also made to inform the inhabitants in the municipality about the ongoing outbreak, the issued boil water recommendation, and medical advice for people with gastrointestinal symptoms. Information was spread via the media, the homepage of the municipality website, posters and local radio as VMA, i.e important message to the public. In addition to the cases reported from the municipality of Lilla Edet, the CMO was notified that 7/17 athletes of a team that had visited the municipality during the afternoon on 7 September had fallen ill with gastrointestinal symptoms 2 days after their visit. To estimate the proportion of the 13000 inhabitants in Lilla Edet that fell sick during the outbreak, questionnaires were sent by mail on 19 September to 1199 randomly selected inhabitants between the ages of 19 and 75 years. A case was defined as a household member with acute gastroenteritis with date of onset between 5 and 21 September. Fifty stool samples from outpatients with symptoms of acute gastroenteritis attending Lilla Edet PHC during 12-26 September were collected and examined for enteric pathogens, as described by Nenonen et al. [20]. Water samples, i.e. raw water from the Gta lv river, drinking water from different parts of the distribution network, and water from reservoirs in Lilla Edet, were collected on 12 September and analyzed at the microbiological laboratory at SMI for the presence of E. coli and coliform bacteria by Colilert 18 (IDEXX, USA), intestinal enterococci by Enterolert (IDEXX), (oo)cysts of Giardia spp. and Cryptosporidium spp. according to ISO 15553:2006, Clostridium perfringens according to ISO/CD 6461-2:2002, somatic coliphages according to ISO 10705-1:2000, Campylobacter spp. by culture on CCDA agar (in-house method), Salmonella spp. according to ISO 6340:1995, Verotoxin-producing E. coli (VTEC) by PCR screening for vt genes and NoV by seminested PCR [22]. Additional water samples were collected on 17 September and analyzed for presence of NoV and coliphages. From the questionnaire survey it could be calculated that out of the 7500 inhabitant that lived in households supplied by drinking water from Lilla Edet WTP, about 2000 (26.7%) fell ill with acute gastroenteritis. NoV was detected in 33/50 stool samples collected from patients with symptoms of acute gastroenteritis. NoV strains of genogroup I (GI) predominated in 31 of these samples and mixed genotypes of GI infections occurred in ve samples, as described by Nenonen et al. [20]. Adenovirus was detected in one, sapovirus in one and rotavirus in three stool samples. Campylobacter spp. were isolated from two stool samples. In samples from the drinking water system in Lilla Edet collected on 12 September, E. coli, coliforms, enterococci, Giardia, Cryptosporidium, Clostridium, Campylobacter or NoV could not be detected, while faecal indicator bacteria and coliphages [300 plaque- forming units (p.f.u.)/100 ml] were found in raw water samples from the Gta lv river. However, somatic coliphages in concentrations between 4 and 42 p.f.u./100 ml were detected in samples from the drinking water system collected on 17 September and in samples from the raw water collected on the same date. In the Lilla Edet outbreak early detection of NoV strain diversity in stool samples strengthened the initial hypothesis that contaminated drinking water was the point source. Thus, the waterborne outbreak in Lilla Edet was most probably a consequence of the heavy faecal contamination of the raw water from Gta lv river [20].

What symptoms did the people had?

{'answer_start': [3200], 'text': ['acute gastroenteritis']}

Contamination Question Answering

A large waterborne outbreak of NoV occurred in Lilla Edet in Sweden in 2008. On 11 September 2008, the County Medical Ofcer (CMO) was informed about an unusually high number of individuals who had suddenly fallen ill with gastrointestinal symptoms during the previous days in Lilla Edet, a small municipality in southwest Sweden. Cases of gastroenteritis were reported from different places in the municipality, e.g. from the nursery schools, schools, nursing homes and from the Primary Healthcare Centre (PHC). The CMO notified the Environmental Office in the municipality about the ongoing outbreak. As the initial information indicated that drinking water was a possible source of the outbreak a boil water recommendation was issued on the same day. Investigations were initiated to identify the causative agents, the extent of the outbreak and possible sources of infection. Efforts were also made to inform the inhabitants in the municipality about the ongoing outbreak, the issued boil water recommendation, and medical advice for people with gastrointestinal symptoms. Information was spread via the media, the homepage of the municipality website, posters and local radio as VMA, i.e important message to the public. In addition to the cases reported from the municipality of Lilla Edet, the CMO was notified that 7/17 athletes of a team that had visited the municipality during the afternoon on 7 September had fallen ill with gastrointestinal symptoms 2 days after their visit. To estimate the proportion of the 13000 inhabitants in Lilla Edet that fell sick during the outbreak, questionnaires were sent by mail on 19 September to 1199 randomly selected inhabitants between the ages of 19 and 75 years. A case was defined as a household member with acute gastroenteritis with date of onset between 5 and 21 September. Fifty stool samples from outpatients with symptoms of acute gastroenteritis attending Lilla Edet PHC during 12-26 September were collected and examined for enteric pathogens, as described by Nenonen et al. [20]. Water samples, i.e. raw water from the Gta lv river, drinking water from different parts of the distribution network, and water from reservoirs in Lilla Edet, were collected on 12 September and analyzed at the microbiological laboratory at SMI for the presence of E. coli and coliform bacteria by Colilert 18 (IDEXX, USA), intestinal enterococci by Enterolert (IDEXX), (oo)cysts of Giardia spp. and Cryptosporidium spp. according to ISO 15553:2006, Clostridium perfringens according to ISO/CD 6461-2:2002, somatic coliphages according to ISO 10705-1:2000, Campylobacter spp. by culture on CCDA agar (in-house method), Salmonella spp. according to ISO 6340:1995, Verotoxin-producing E. coli (VTEC) by PCR screening for vt genes and NoV by seminested PCR [22]. Additional water samples were collected on 17 September and analyzed for presence of NoV and coliphages. From the questionnaire survey it could be calculated that out of the 7500 inhabitant that lived in households supplied by drinking water from Lilla Edet WTP, about 2000 (26.7%) fell ill with acute gastroenteritis. NoV was detected in 33/50 stool samples collected from patients with symptoms of acute gastroenteritis. NoV strains of genogroup I (GI) predominated in 31 of these samples and mixed genotypes of GI infections occurred in ve samples, as described by Nenonen et al. [20]. Adenovirus was detected in one, sapovirus in one and rotavirus in three stool samples. Campylobacter spp. were isolated from two stool samples. In samples from the drinking water system in Lilla Edet collected on 12 September, E. coli, coliforms, enterococci, Giardia, Cryptosporidium, Clostridium, Campylobacter or NoV could not be detected, while faecal indicator bacteria and coliphages [300 plaque- forming units (p.f.u.)/100 ml] were found in raw water samples from the Gta lv river. However, somatic coliphages in concentrations between 4 and 42 p.f.u./100 ml were detected in samples from the drinking water system collected on 17 September and in samples from the raw water collected on the same date. In the Lilla Edet outbreak early detection of NoV strain diversity in stool samples strengthened the initial hypothesis that contaminated drinking water was the point source. Thus, the waterborne outbreak in Lilla Edet was most probably a consequence of the heavy faecal contamination of the raw water from Gta lv river [20].

What type of samples were analyzed?

{'answer_start': [1835], 'text': ['stool samples']}

Contamination Question Answering

A large waterborne outbreak of NoV occurred in Lilla Edet in Sweden in 2008. On 11 September 2008, the County Medical Ofcer (CMO) was informed about an unusually high number of individuals who had suddenly fallen ill with gastrointestinal symptoms during the previous days in Lilla Edet, a small municipality in southwest Sweden. Cases of gastroenteritis were reported from different places in the municipality, e.g. from the nursery schools, schools, nursing homes and from the Primary Healthcare Centre (PHC). The CMO notified the Environmental Office in the municipality about the ongoing outbreak. As the initial information indicated that drinking water was a possible source of the outbreak a boil water recommendation was issued on the same day. Investigations were initiated to identify the causative agents, the extent of the outbreak and possible sources of infection. Efforts were also made to inform the inhabitants in the municipality about the ongoing outbreak, the issued boil water recommendation, and medical advice for people with gastrointestinal symptoms. Information was spread via the media, the homepage of the municipality website, posters and local radio as VMA, i.e important message to the public. In addition to the cases reported from the municipality of Lilla Edet, the CMO was notified that 7/17 athletes of a team that had visited the municipality during the afternoon on 7 September had fallen ill with gastrointestinal symptoms 2 days after their visit. To estimate the proportion of the 13000 inhabitants in Lilla Edet that fell sick during the outbreak, questionnaires were sent by mail on 19 September to 1199 randomly selected inhabitants between the ages of 19 and 75 years. A case was defined as a household member with acute gastroenteritis with date of onset between 5 and 21 September. Fifty stool samples from outpatients with symptoms of acute gastroenteritis attending Lilla Edet PHC during 12-26 September were collected and examined for enteric pathogens, as described by Nenonen et al. [20]. Water samples, i.e. raw water from the Gta lv river, drinking water from different parts of the distribution network, and water from reservoirs in Lilla Edet, were collected on 12 September and analyzed at the microbiological laboratory at SMI for the presence of E. coli and coliform bacteria by Colilert 18 (IDEXX, USA), intestinal enterococci by Enterolert (IDEXX), (oo)cysts of Giardia spp. and Cryptosporidium spp. according to ISO 15553:2006, Clostridium perfringens according to ISO/CD 6461-2:2002, somatic coliphages according to ISO 10705-1:2000, Campylobacter spp. by culture on CCDA agar (in-house method), Salmonella spp. according to ISO 6340:1995, Verotoxin-producing E. coli (VTEC) by PCR screening for vt genes and NoV by seminested PCR [22]. Additional water samples were collected on 17 September and analyzed for presence of NoV and coliphages. From the questionnaire survey it could be calculated that out of the 7500 inhabitant that lived in households supplied by drinking water from Lilla Edet WTP, about 2000 (26.7%) fell ill with acute gastroenteritis. NoV was detected in 33/50 stool samples collected from patients with symptoms of acute gastroenteritis. NoV strains of genogroup I (GI) predominated in 31 of these samples and mixed genotypes of GI infections occurred in ve samples, as described by Nenonen et al. [20]. Adenovirus was detected in one, sapovirus in one and rotavirus in three stool samples. Campylobacter spp. were isolated from two stool samples. In samples from the drinking water system in Lilla Edet collected on 12 September, E. coli, coliforms, enterococci, Giardia, Cryptosporidium, Clostridium, Campylobacter or NoV could not be detected, while faecal indicator bacteria and coliphages [300 plaque- forming units (p.f.u.)/100 ml] were found in raw water samples from the Gta lv river. However, somatic coliphages in concentrations between 4 and 42 p.f.u./100 ml were detected in samples from the drinking water system collected on 17 September and in samples from the raw water collected on the same date. In the Lilla Edet outbreak early detection of NoV strain diversity in stool samples strengthened the initial hypothesis that contaminated drinking water was the point source. Thus, the waterborne outbreak in Lilla Edet was most probably a consequence of the heavy faecal contamination of the raw water from Gta lv river [20].

What caused the event?

{'answer_start': [4363], 'text': ['faecal contamination']}

Contamination Question Answering

A large waterborne outbreak of NoV occurred in Lilla Edet in Sweden in 2008. On 11 September 2008, the County Medical Ofcer (CMO) was informed about an unusually high number of individuals who had suddenly fallen ill with gastrointestinal symptoms during the previous days in Lilla Edet, a small municipality in southwest Sweden. Cases of gastroenteritis were reported from different places in the municipality, e.g. from the nursery schools, schools, nursing homes and from the Primary Healthcare Centre (PHC). The CMO notified the Environmental Office in the municipality about the ongoing outbreak. As the initial information indicated that drinking water was a possible source of the outbreak a boil water recommendation was issued on the same day. Investigations were initiated to identify the causative agents, the extent of the outbreak and possible sources of infection. Efforts were also made to inform the inhabitants in the municipality about the ongoing outbreak, the issued boil water recommendation, and medical advice for people with gastrointestinal symptoms. Information was spread via the media, the homepage of the municipality website, posters and local radio as VMA, i.e important message to the public. In addition to the cases reported from the municipality of Lilla Edet, the CMO was notified that 7/17 athletes of a team that had visited the municipality during the afternoon on 7 September had fallen ill with gastrointestinal symptoms 2 days after their visit. To estimate the proportion of the 13000 inhabitants in Lilla Edet that fell sick during the outbreak, questionnaires were sent by mail on 19 September to 1199 randomly selected inhabitants between the ages of 19 and 75 years. A case was defined as a household member with acute gastroenteritis with date of onset between 5 and 21 September. Fifty stool samples from outpatients with symptoms of acute gastroenteritis attending Lilla Edet PHC during 12-26 September were collected and examined for enteric pathogens, as described by Nenonen et al. [20]. Water samples, i.e. raw water from the Gta lv river, drinking water from different parts of the distribution network, and water from reservoirs in Lilla Edet, were collected on 12 September and analyzed at the microbiological laboratory at SMI for the presence of E. coli and coliform bacteria by Colilert 18 (IDEXX, USA), intestinal enterococci by Enterolert (IDEXX), (oo)cysts of Giardia spp. and Cryptosporidium spp. according to ISO 15553:2006, Clostridium perfringens according to ISO/CD 6461-2:2002, somatic coliphages according to ISO 10705-1:2000, Campylobacter spp. by culture on CCDA agar (in-house method), Salmonella spp. according to ISO 6340:1995, Verotoxin-producing E. coli (VTEC) by PCR screening for vt genes and NoV by seminested PCR [22]. Additional water samples were collected on 17 September and analyzed for presence of NoV and coliphages. From the questionnaire survey it could be calculated that out of the 7500 inhabitant that lived in households supplied by drinking water from Lilla Edet WTP, about 2000 (26.7%) fell ill with acute gastroenteritis. NoV was detected in 33/50 stool samples collected from patients with symptoms of acute gastroenteritis. NoV strains of genogroup I (GI) predominated in 31 of these samples and mixed genotypes of GI infections occurred in ve samples, as described by Nenonen et al. [20]. Adenovirus was detected in one, sapovirus in one and rotavirus in three stool samples. Campylobacter spp. were isolated from two stool samples. In samples from the drinking water system in Lilla Edet collected on 12 September, E. coli, coliforms, enterococci, Giardia, Cryptosporidium, Clostridium, Campylobacter or NoV could not be detected, while faecal indicator bacteria and coliphages [300 plaque- forming units (p.f.u.)/100 ml] were found in raw water samples from the Gta lv river. However, somatic coliphages in concentrations between 4 and 42 p.f.u./100 ml were detected in samples from the drinking water system collected on 17 September and in samples from the raw water collected on the same date. In the Lilla Edet outbreak early detection of NoV strain diversity in stool samples strengthened the initial hypothesis that contaminated drinking water was the point source. Thus, the waterborne outbreak in Lilla Edet was most probably a consequence of the heavy faecal contamination of the raw water from Gta lv river [20].

What symptoms did people report?

{'answer_start': [1766], 'text': ['gastroenteritis']}

Contamination Question Answering

A large waterborne outbreak of NoV occurred in Lilla Edet in Sweden in 2008. On 11 September 2008, the County Medical Ofcer (CMO) was informed about an unusually high number of individuals who had suddenly fallen ill with gastrointestinal symptoms during the previous days in Lilla Edet, a small municipality in southwest Sweden. Cases of gastroenteritis were reported from different places in the municipality, e.g. from the nursery schools, schools, nursing homes and from the Primary Healthcare Centre (PHC). The CMO notified the Environmental Office in the municipality about the ongoing outbreak. As the initial information indicated that drinking water was a possible source of the outbreak a boil water recommendation was issued on the same day. Investigations were initiated to identify the causative agents, the extent of the outbreak and possible sources of infection. Efforts were also made to inform the inhabitants in the municipality about the ongoing outbreak, the issued boil water recommendation, and medical advice for people with gastrointestinal symptoms. Information was spread via the media, the homepage of the municipality website, posters and local radio as VMA, i.e important message to the public. In addition to the cases reported from the municipality of Lilla Edet, the CMO was notified that 7/17 athletes of a team that had visited the municipality during the afternoon on 7 September had fallen ill with gastrointestinal symptoms 2 days after their visit. To estimate the proportion of the 13000 inhabitants in Lilla Edet that fell sick during the outbreak, questionnaires were sent by mail on 19 September to 1199 randomly selected inhabitants between the ages of 19 and 75 years. A case was defined as a household member with acute gastroenteritis with date of onset between 5 and 21 September. Fifty stool samples from outpatients with symptoms of acute gastroenteritis attending Lilla Edet PHC during 12-26 September were collected and examined for enteric pathogens, as described by Nenonen et al. [20]. Water samples, i.e. raw water from the Gta lv river, drinking water from different parts of the distribution network, and water from reservoirs in Lilla Edet, were collected on 12 September and analyzed at the microbiological laboratory at SMI for the presence of E. coli and coliform bacteria by Colilert 18 (IDEXX, USA), intestinal enterococci by Enterolert (IDEXX), (oo)cysts of Giardia spp. and Cryptosporidium spp. according to ISO 15553:2006, Clostridium perfringens according to ISO/CD 6461-2:2002, somatic coliphages according to ISO 10705-1:2000, Campylobacter spp. by culture on CCDA agar (in-house method), Salmonella spp. according to ISO 6340:1995, Verotoxin-producing E. coli (VTEC) by PCR screening for vt genes and NoV by seminested PCR [22]. Additional water samples were collected on 17 September and analyzed for presence of NoV and coliphages. From the questionnaire survey it could be calculated that out of the 7500 inhabitant that lived in households supplied by drinking water from Lilla Edet WTP, about 2000 (26.7%) fell ill with acute gastroenteritis. NoV was detected in 33/50 stool samples collected from patients with symptoms of acute gastroenteritis. NoV strains of genogroup I (GI) predominated in 31 of these samples and mixed genotypes of GI infections occurred in ve samples, as described by Nenonen et al. [20]. Adenovirus was detected in one, sapovirus in one and rotavirus in three stool samples. Campylobacter spp. were isolated from two stool samples. In samples from the drinking water system in Lilla Edet collected on 12 September, E. coli, coliforms, enterococci, Giardia, Cryptosporidium, Clostridium, Campylobacter or NoV could not be detected, while faecal indicator bacteria and coliphages [300 plaque- forming units (p.f.u.)/100 ml] were found in raw water samples from the Gta lv river. However, somatic coliphages in concentrations between 4 and 42 p.f.u./100 ml were detected in samples from the drinking water system collected on 17 September and in samples from the raw water collected on the same date. In the Lilla Edet outbreak early detection of NoV strain diversity in stool samples strengthened the initial hypothesis that contaminated drinking water was the point source. Thus, the waterborne outbreak in Lilla Edet was most probably a consequence of the heavy faecal contamination of the raw water from Gta lv river [20].

What were the first steps of investigation?

{'answer_start': [1590], 'text': ['questionnaires']}

Contamination Question Answering

A large waterborne outbreak of NoV occurred in Lilla Edet in Sweden in 2008. On 11 September 2008, the County Medical Ofcer (CMO) was informed about an unusually high number of individuals who had suddenly fallen ill with gastrointestinal symptoms during the previous days in Lilla Edet, a small municipality in southwest Sweden. Cases of gastroenteritis were reported from different places in the municipality, e.g. from the nursery schools, schools, nursing homes and from the Primary Healthcare Centre (PHC). The CMO notified the Environmental Office in the municipality about the ongoing outbreak. As the initial information indicated that drinking water was a possible source of the outbreak a boil water recommendation was issued on the same day. Investigations were initiated to identify the causative agents, the extent of the outbreak and possible sources of infection. Efforts were also made to inform the inhabitants in the municipality about the ongoing outbreak, the issued boil water recommendation, and medical advice for people with gastrointestinal symptoms. Information was spread via the media, the homepage of the municipality website, posters and local radio as VMA, i.e important message to the public. In addition to the cases reported from the municipality of Lilla Edet, the CMO was notified that 7/17 athletes of a team that had visited the municipality during the afternoon on 7 September had fallen ill with gastrointestinal symptoms 2 days after their visit. To estimate the proportion of the 13000 inhabitants in Lilla Edet that fell sick during the outbreak, questionnaires were sent by mail on 19 September to 1199 randomly selected inhabitants between the ages of 19 and 75 years. A case was defined as a household member with acute gastroenteritis with date of onset between 5 and 21 September. Fifty stool samples from outpatients with symptoms of acute gastroenteritis attending Lilla Edet PHC during 12-26 September were collected and examined for enteric pathogens, as described by Nenonen et al. [20]. Water samples, i.e. raw water from the Gta lv river, drinking water from different parts of the distribution network, and water from reservoirs in Lilla Edet, were collected on 12 September and analyzed at the microbiological laboratory at SMI for the presence of E. coli and coliform bacteria by Colilert 18 (IDEXX, USA), intestinal enterococci by Enterolert (IDEXX), (oo)cysts of Giardia spp. and Cryptosporidium spp. according to ISO 15553:2006, Clostridium perfringens according to ISO/CD 6461-2:2002, somatic coliphages according to ISO 10705-1:2000, Campylobacter spp. by culture on CCDA agar (in-house method), Salmonella spp. according to ISO 6340:1995, Verotoxin-producing E. coli (VTEC) by PCR screening for vt genes and NoV by seminested PCR [22]. Additional water samples were collected on 17 September and analyzed for presence of NoV and coliphages. From the questionnaire survey it could be calculated that out of the 7500 inhabitant that lived in households supplied by drinking water from Lilla Edet WTP, about 2000 (26.7%) fell ill with acute gastroenteritis. NoV was detected in 33/50 stool samples collected from patients with symptoms of acute gastroenteritis. NoV strains of genogroup I (GI) predominated in 31 of these samples and mixed genotypes of GI infections occurred in ve samples, as described by Nenonen et al. [20]. Adenovirus was detected in one, sapovirus in one and rotavirus in three stool samples. Campylobacter spp. were isolated from two stool samples. In samples from the drinking water system in Lilla Edet collected on 12 September, E. coli, coliforms, enterococci, Giardia, Cryptosporidium, Clostridium, Campylobacter or NoV could not be detected, while faecal indicator bacteria and coliphages [300 plaque- forming units (p.f.u.)/100 ml] were found in raw water samples from the Gta lv river. However, somatic coliphages in concentrations between 4 and 42 p.f.u./100 ml were detected in samples from the drinking water system collected on 17 September and in samples from the raw water collected on the same date. In the Lilla Edet outbreak early detection of NoV strain diversity in stool samples strengthened the initial hypothesis that contaminated drinking water was the point source. Thus, the waterborne outbreak in Lilla Edet was most probably a consequence of the heavy faecal contamination of the raw water from Gta lv river [20].

What is the date of the event?

{'answer_start': [71], 'text': ['2008']}

Contamination Question Answering

A large waterborne outbreak of NoV occurred in Lilla Edet in Sweden in 2008. On 11 September 2008, the County Medical Ofcer (CMO) was informed about an unusually high number of individuals who had suddenly fallen ill with gastrointestinal symptoms during the previous days in Lilla Edet, a small municipality in southwest Sweden. Cases of gastroenteritis were reported from different places in the municipality, e.g. from the nursery schools, schools, nursing homes and from the Primary Healthcare Centre (PHC). The CMO notified the Environmental Office in the municipality about the ongoing outbreak. As the initial information indicated that drinking water was a possible source of the outbreak a boil water recommendation was issued on the same day. Investigations were initiated to identify the causative agents, the extent of the outbreak and possible sources of infection. Efforts were also made to inform the inhabitants in the municipality about the ongoing outbreak, the issued boil water recommendation, and medical advice for people with gastrointestinal symptoms. Information was spread via the media, the homepage of the municipality website, posters and local radio as VMA, i.e important message to the public. In addition to the cases reported from the municipality of Lilla Edet, the CMO was notified that 7/17 athletes of a team that had visited the municipality during the afternoon on 7 September had fallen ill with gastrointestinal symptoms 2 days after their visit. To estimate the proportion of the 13000 inhabitants in Lilla Edet that fell sick during the outbreak, questionnaires were sent by mail on 19 September to 1199 randomly selected inhabitants between the ages of 19 and 75 years. A case was defined as a household member with acute gastroenteritis with date of onset between 5 and 21 September. Fifty stool samples from outpatients with symptoms of acute gastroenteritis attending Lilla Edet PHC during 12-26 September were collected and examined for enteric pathogens, as described by Nenonen et al. [20]. Water samples, i.e. raw water from the Gta lv river, drinking water from different parts of the distribution network, and water from reservoirs in Lilla Edet, were collected on 12 September and analyzed at the microbiological laboratory at SMI for the presence of E. coli and coliform bacteria by Colilert 18 (IDEXX, USA), intestinal enterococci by Enterolert (IDEXX), (oo)cysts of Giardia spp. and Cryptosporidium spp. according to ISO 15553:2006, Clostridium perfringens according to ISO/CD 6461-2:2002, somatic coliphages according to ISO 10705-1:2000, Campylobacter spp. by culture on CCDA agar (in-house method), Salmonella spp. according to ISO 6340:1995, Verotoxin-producing E. coli (VTEC) by PCR screening for vt genes and NoV by seminested PCR [22]. Additional water samples were collected on 17 September and analyzed for presence of NoV and coliphages. From the questionnaire survey it could be calculated that out of the 7500 inhabitant that lived in households supplied by drinking water from Lilla Edet WTP, about 2000 (26.7%) fell ill with acute gastroenteritis. NoV was detected in 33/50 stool samples collected from patients with symptoms of acute gastroenteritis. NoV strains of genogroup I (GI) predominated in 31 of these samples and mixed genotypes of GI infections occurred in ve samples, as described by Nenonen et al. [20]. Adenovirus was detected in one, sapovirus in one and rotavirus in three stool samples. Campylobacter spp. were isolated from two stool samples. In samples from the drinking water system in Lilla Edet collected on 12 September, E. coli, coliforms, enterococci, Giardia, Cryptosporidium, Clostridium, Campylobacter or NoV could not be detected, while faecal indicator bacteria and coliphages [300 plaque- forming units (p.f.u.)/100 ml] were found in raw water samples from the Gta lv river. However, somatic coliphages in concentrations between 4 and 42 p.f.u./100 ml were detected in samples from the drinking water system collected on 17 September and in samples from the raw water collected on the same date. In the Lilla Edet outbreak early detection of NoV strain diversity in stool samples strengthened the initial hypothesis that contaminated drinking water was the point source. Thus, the waterborne outbreak in Lilla Edet was most probably a consequence of the heavy faecal contamination of the raw water from Gta lv river [20].

What is the location of the event?

{'answer_start': [61], 'text': ['Sweden']}

Contamination Question Answering

A large waterborne outbreak of NoV occurred in Lilla Edet in Sweden in 2008. On 11 September 2008, the County Medical Ofcer (CMO) was informed about an unusually high number of individuals who had suddenly fallen ill with gastrointestinal symptoms during the previous days in Lilla Edet, a small municipality in southwest Sweden. Cases of gastroenteritis were reported from different places in the municipality, e.g. from the nursery schools, schools, nursing homes and from the Primary Healthcare Centre (PHC). The CMO notified the Environmental Office in the municipality about the ongoing outbreak. As the initial information indicated that drinking water was a possible source of the outbreak a boil water recommendation was issued on the same day. Investigations were initiated to identify the causative agents, the extent of the outbreak and possible sources of infection. Efforts were also made to inform the inhabitants in the municipality about the ongoing outbreak, the issued boil water recommendation, and medical advice for people with gastrointestinal symptoms. Information was spread via the media, the homepage of the municipality website, posters and local radio as VMA, i.e important message to the public. In addition to the cases reported from the municipality of Lilla Edet, the CMO was notified that 7/17 athletes of a team that had visited the municipality during the afternoon on 7 September had fallen ill with gastrointestinal symptoms 2 days after their visit. To estimate the proportion of the 13000 inhabitants in Lilla Edet that fell sick during the outbreak, questionnaires were sent by mail on 19 September to 1199 randomly selected inhabitants between the ages of 19 and 75 years. A case was defined as a household member with acute gastroenteritis with date of onset between 5 and 21 September. Fifty stool samples from outpatients with symptoms of acute gastroenteritis attending Lilla Edet PHC during 12-26 September were collected and examined for enteric pathogens, as described by Nenonen et al. [20]. Water samples, i.e. raw water from the Gta lv river, drinking water from different parts of the distribution network, and water from reservoirs in Lilla Edet, were collected on 12 September and analyzed at the microbiological laboratory at SMI for the presence of E. coli and coliform bacteria by Colilert 18 (IDEXX, USA), intestinal enterococci by Enterolert (IDEXX), (oo)cysts of Giardia spp. and Cryptosporidium spp. according to ISO 15553:2006, Clostridium perfringens according to ISO/CD 6461-2:2002, somatic coliphages according to ISO 10705-1:2000, Campylobacter spp. by culture on CCDA agar (in-house method), Salmonella spp. according to ISO 6340:1995, Verotoxin-producing E. coli (VTEC) by PCR screening for vt genes and NoV by seminested PCR [22]. Additional water samples were collected on 17 September and analyzed for presence of NoV and coliphages. From the questionnaire survey it could be calculated that out of the 7500 inhabitant that lived in households supplied by drinking water from Lilla Edet WTP, about 2000 (26.7%) fell ill with acute gastroenteritis. NoV was detected in 33/50 stool samples collected from patients with symptoms of acute gastroenteritis. NoV strains of genogroup I (GI) predominated in 31 of these samples and mixed genotypes of GI infections occurred in ve samples, as described by Nenonen et al. [20]. Adenovirus was detected in one, sapovirus in one and rotavirus in three stool samples. Campylobacter spp. were isolated from two stool samples. In samples from the drinking water system in Lilla Edet collected on 12 September, E. coli, coliforms, enterococci, Giardia, Cryptosporidium, Clostridium, Campylobacter or NoV could not be detected, while faecal indicator bacteria and coliphages [300 plaque- forming units (p.f.u.)/100 ml] were found in raw water samples from the Gta lv river. However, somatic coliphages in concentrations between 4 and 42 p.f.u./100 ml were detected in samples from the drinking water system collected on 17 September and in samples from the raw water collected on the same date. In the Lilla Edet outbreak early detection of NoV strain diversity in stool samples strengthened the initial hypothesis that contaminated drinking water was the point source. Thus, the waterborne outbreak in Lilla Edet was most probably a consequence of the heavy faecal contamination of the raw water from Gta lv river [20].

What pathogen was connected to the outbreak?

{'answer_start': [3738], 'text': ['faecal indicator bacteria and coliphages']}

Contamination Question Answering

A large waterborne outbreak of NoV occurred in Lilla Edet in Sweden in 2008. On 11 September 2008, the County Medical Ofcer (CMO) was informed about an unusually high number of individuals who had suddenly fallen ill with gastrointestinal symptoms during the previous days in Lilla Edet, a small municipality in southwest Sweden. Cases of gastroenteritis were reported from different places in the municipality, e.g. from the nursery schools, schools, nursing homes and from the Primary Healthcare Centre (PHC). The CMO notified the Environmental Office in the municipality about the ongoing outbreak. As the initial information indicated that drinking water was a possible source of the outbreak a boil water recommendation was issued on the same day. Investigations were initiated to identify the causative agents, the extent of the outbreak and possible sources of infection. Efforts were also made to inform the inhabitants in the municipality about the ongoing outbreak, the issued boil water recommendation, and medical advice for people with gastrointestinal symptoms. Information was spread via the media, the homepage of the municipality website, posters and local radio as VMA, i.e important message to the public. In addition to the cases reported from the municipality of Lilla Edet, the CMO was notified that 7/17 athletes of a team that had visited the municipality during the afternoon on 7 September had fallen ill with gastrointestinal symptoms 2 days after their visit. To estimate the proportion of the 13000 inhabitants in Lilla Edet that fell sick during the outbreak, questionnaires were sent by mail on 19 September to 1199 randomly selected inhabitants between the ages of 19 and 75 years. A case was defined as a household member with acute gastroenteritis with date of onset between 5 and 21 September. Fifty stool samples from outpatients with symptoms of acute gastroenteritis attending Lilla Edet PHC during 12-26 September were collected and examined for enteric pathogens, as described by Nenonen et al. [20]. Water samples, i.e. raw water from the Gta lv river, drinking water from different parts of the distribution network, and water from reservoirs in Lilla Edet, were collected on 12 September and analyzed at the microbiological laboratory at SMI for the presence of E. coli and coliform bacteria by Colilert 18 (IDEXX, USA), intestinal enterococci by Enterolert (IDEXX), (oo)cysts of Giardia spp. and Cryptosporidium spp. according to ISO 15553:2006, Clostridium perfringens according to ISO/CD 6461-2:2002, somatic coliphages according to ISO 10705-1:2000, Campylobacter spp. by culture on CCDA agar (in-house method), Salmonella spp. according to ISO 6340:1995, Verotoxin-producing E. coli (VTEC) by PCR screening for vt genes and NoV by seminested PCR [22]. Additional water samples were collected on 17 September and analyzed for presence of NoV and coliphages. From the questionnaire survey it could be calculated that out of the 7500 inhabitant that lived in households supplied by drinking water from Lilla Edet WTP, about 2000 (26.7%) fell ill with acute gastroenteritis. NoV was detected in 33/50 stool samples collected from patients with symptoms of acute gastroenteritis. NoV strains of genogroup I (GI) predominated in 31 of these samples and mixed genotypes of GI infections occurred in ve samples, as described by Nenonen et al. [20]. Adenovirus was detected in one, sapovirus in one and rotavirus in three stool samples. Campylobacter spp. were isolated from two stool samples. In samples from the drinking water system in Lilla Edet collected on 12 September, E. coli, coliforms, enterococci, Giardia, Cryptosporidium, Clostridium, Campylobacter or NoV could not be detected, while faecal indicator bacteria and coliphages [300 plaque- forming units (p.f.u.)/100 ml] were found in raw water samples from the Gta lv river. However, somatic coliphages in concentrations between 4 and 42 p.f.u./100 ml were detected in samples from the drinking water system collected on 17 September and in samples from the raw water collected on the same date. In the Lilla Edet outbreak early detection of NoV strain diversity in stool samples strengthened the initial hypothesis that contaminated drinking water was the point source. Thus, the waterborne outbreak in Lilla Edet was most probably a consequence of the heavy faecal contamination of the raw water from Gta lv river [20].

What is the source that started the event?

{'answer_start': [4224], 'text': ['contaminated drinking water']}

Contamination Question Answering

A large waterborne outbreak of NoV occurred in Lilla Edet in Sweden in 2008. On 11 September 2008, the County Medical Ofcer (CMO) was informed about an unusually high number of individuals who had suddenly fallen ill with gastrointestinal symptoms during the previous days in Lilla Edet, a small municipality in southwest Sweden. Cases of gastroenteritis were reported from different places in the municipality, e.g. from the nursery schools, schools, nursing homes and from the Primary Healthcare Centre (PHC). The CMO notified the Environmental Office in the municipality about the ongoing outbreak. As the initial information indicated that drinking water was a possible source of the outbreak a boil water recommendation was issued on the same day. Investigations were initiated to identify the causative agents, the extent of the outbreak and possible sources of infection. Efforts were also made to inform the inhabitants in the municipality about the ongoing outbreak, the issued boil water recommendation, and medical advice for people with gastrointestinal symptoms. Information was spread via the media, the homepage of the municipality website, posters and local radio as VMA, i.e important message to the public. In addition to the cases reported from the municipality of Lilla Edet, the CMO was notified that 7/17 athletes of a team that had visited the municipality during the afternoon on 7 September had fallen ill with gastrointestinal symptoms 2 days after their visit. To estimate the proportion of the 13000 inhabitants in Lilla Edet that fell sick during the outbreak, questionnaires were sent by mail on 19 September to 1199 randomly selected inhabitants between the ages of 19 and 75 years. A case was defined as a household member with acute gastroenteritis with date of onset between 5 and 21 September. Fifty stool samples from outpatients with symptoms of acute gastroenteritis attending Lilla Edet PHC during 12-26 September were collected and examined for enteric pathogens, as described by Nenonen et al. [20]. Water samples, i.e. raw water from the Gta lv river, drinking water from different parts of the distribution network, and water from reservoirs in Lilla Edet, were collected on 12 September and analyzed at the microbiological laboratory at SMI for the presence of E. coli and coliform bacteria by Colilert 18 (IDEXX, USA), intestinal enterococci by Enterolert (IDEXX), (oo)cysts of Giardia spp. and Cryptosporidium spp. according to ISO 15553:2006, Clostridium perfringens according to ISO/CD 6461-2:2002, somatic coliphages according to ISO 10705-1:2000, Campylobacter spp. by culture on CCDA agar (in-house method), Salmonella spp. according to ISO 6340:1995, Verotoxin-producing E. coli (VTEC) by PCR screening for vt genes and NoV by seminested PCR [22]. Additional water samples were collected on 17 September and analyzed for presence of NoV and coliphages. From the questionnaire survey it could be calculated that out of the 7500 inhabitant that lived in households supplied by drinking water from Lilla Edet WTP, about 2000 (26.7%) fell ill with acute gastroenteritis. NoV was detected in 33/50 stool samples collected from patients with symptoms of acute gastroenteritis. NoV strains of genogroup I (GI) predominated in 31 of these samples and mixed genotypes of GI infections occurred in ve samples, as described by Nenonen et al. [20]. Adenovirus was detected in one, sapovirus in one and rotavirus in three stool samples. Campylobacter spp. were isolated from two stool samples. In samples from the drinking water system in Lilla Edet collected on 12 September, E. coli, coliforms, enterococci, Giardia, Cryptosporidium, Clostridium, Campylobacter or NoV could not be detected, while faecal indicator bacteria and coliphages [300 plaque- forming units (p.f.u.)/100 ml] were found in raw water samples from the Gta lv river. However, somatic coliphages in concentrations between 4 and 42 p.f.u./100 ml were detected in samples from the drinking water system collected on 17 September and in samples from the raw water collected on the same date. In the Lilla Edet outbreak early detection of NoV strain diversity in stool samples strengthened the initial hypothesis that contaminated drinking water was the point source. Thus, the waterborne outbreak in Lilla Edet was most probably a consequence of the heavy faecal contamination of the raw water from Gta lv river [20].

How was the event first detected?

{'answer_start': [162], 'text': ['high number of individuals ']}

Contamination Question Answering

A large waterborne outbreak of NoV occurred in Lilla Edet in Sweden in 2008. On 11 September 2008, the County Medical Ofcer (CMO) was informed about an unusually high number of individuals who had suddenly fallen ill with gastrointestinal symptoms during the previous days in Lilla Edet, a small municipality in southwest Sweden. Cases of gastroenteritis were reported from different places in the municipality, e.g. from the nursery schools, schools, nursing homes and from the Primary Healthcare Centre (PHC). The CMO notified the Environmental Office in the municipality about the ongoing outbreak. As the initial information indicated that drinking water was a possible source of the outbreak a boil water recommendation was issued on the same day. Investigations were initiated to identify the causative agents, the extent of the outbreak and possible sources of infection. Efforts were also made to inform the inhabitants in the municipality about the ongoing outbreak, the issued boil water recommendation, and medical advice for people with gastrointestinal symptoms. Information was spread via the media, the homepage of the municipality website, posters and local radio as VMA, i.e important message to the public. In addition to the cases reported from the municipality of Lilla Edet, the CMO was notified that 7/17 athletes of a team that had visited the municipality during the afternoon on 7 September had fallen ill with gastrointestinal symptoms 2 days after their visit. To estimate the proportion of the 13000 inhabitants in Lilla Edet that fell sick during the outbreak, questionnaires were sent by mail on 19 September to 1199 randomly selected inhabitants between the ages of 19 and 75 years. A case was defined as a household member with acute gastroenteritis with date of onset between 5 and 21 September. Fifty stool samples from outpatients with symptoms of acute gastroenteritis attending Lilla Edet PHC during 12-26 September were collected and examined for enteric pathogens, as described by Nenonen et al. [20]. Water samples, i.e. raw water from the Gta lv river, drinking water from different parts of the distribution network, and water from reservoirs in Lilla Edet, were collected on 12 September and analyzed at the microbiological laboratory at SMI for the presence of E. coli and coliform bacteria by Colilert 18 (IDEXX, USA), intestinal enterococci by Enterolert (IDEXX), (oo)cysts of Giardia spp. and Cryptosporidium spp. according to ISO 15553:2006, Clostridium perfringens according to ISO/CD 6461-2:2002, somatic coliphages according to ISO 10705-1:2000, Campylobacter spp. by culture on CCDA agar (in-house method), Salmonella spp. according to ISO 6340:1995, Verotoxin-producing E. coli (VTEC) by PCR screening for vt genes and NoV by seminested PCR [22]. Additional water samples were collected on 17 September and analyzed for presence of NoV and coliphages. From the questionnaire survey it could be calculated that out of the 7500 inhabitant that lived in households supplied by drinking water from Lilla Edet WTP, about 2000 (26.7%) fell ill with acute gastroenteritis. NoV was detected in 33/50 stool samples collected from patients with symptoms of acute gastroenteritis. NoV strains of genogroup I (GI) predominated in 31 of these samples and mixed genotypes of GI infections occurred in ve samples, as described by Nenonen et al. [20]. Adenovirus was detected in one, sapovirus in one and rotavirus in three stool samples. Campylobacter spp. were isolated from two stool samples. In samples from the drinking water system in Lilla Edet collected on 12 September, E. coli, coliforms, enterococci, Giardia, Cryptosporidium, Clostridium, Campylobacter or NoV could not be detected, while faecal indicator bacteria and coliphages [300 plaque- forming units (p.f.u.)/100 ml] were found in raw water samples from the Gta lv river. However, somatic coliphages in concentrations between 4 and 42 p.f.u./100 ml were detected in samples from the drinking water system collected on 17 September and in samples from the raw water collected on the same date. In the Lilla Edet outbreak early detection of NoV strain diversity in stool samples strengthened the initial hypothesis that contaminated drinking water was the point source. Thus, the waterborne outbreak in Lilla Edet was most probably a consequence of the heavy faecal contamination of the raw water from Gta lv river [20].

How many people were ill?

{'answer_start': [3069], 'text': ['2000']}

Contamination Question Answering

A large waterborne outbreak of NoV occurred in Lilla Edet in Sweden in 2008. On 11 September 2008, the County Medical Ofcer (CMO) was informed about an unusually high number of individuals who had suddenly fallen ill with gastrointestinal symptoms during the previous days in Lilla Edet, a small municipality in southwest Sweden. Cases of gastroenteritis were reported from different places in the municipality, e.g. from the nursery schools, schools, nursing homes and from the Primary Healthcare Centre (PHC). The CMO notified the Environmental Office in the municipality about the ongoing outbreak. As the initial information indicated that drinking water was a possible source of the outbreak a boil water recommendation was issued on the same day. Investigations were initiated to identify the causative agents, the extent of the outbreak and possible sources of infection. Efforts were also made to inform the inhabitants in the municipality about the ongoing outbreak, the issued boil water recommendation, and medical advice for people with gastrointestinal symptoms. Information was spread via the media, the homepage of the municipality website, posters and local radio as VMA, i.e important message to the public. In addition to the cases reported from the municipality of Lilla Edet, the CMO was notified that 7/17 athletes of a team that had visited the municipality during the afternoon on 7 September had fallen ill with gastrointestinal symptoms 2 days after their visit. To estimate the proportion of the 13000 inhabitants in Lilla Edet that fell sick during the outbreak, questionnaires were sent by mail on 19 September to 1199 randomly selected inhabitants between the ages of 19 and 75 years. A case was defined as a household member with acute gastroenteritis with date of onset between 5 and 21 September. Fifty stool samples from outpatients with symptoms of acute gastroenteritis attending Lilla Edet PHC during 12-26 September were collected and examined for enteric pathogens, as described by Nenonen et al. [20]. Water samples, i.e. raw water from the Gta lv river, drinking water from different parts of the distribution network, and water from reservoirs in Lilla Edet, were collected on 12 September and analyzed at the microbiological laboratory at SMI for the presence of E. coli and coliform bacteria by Colilert 18 (IDEXX, USA), intestinal enterococci by Enterolert (IDEXX), (oo)cysts of Giardia spp. and Cryptosporidium spp. according to ISO 15553:2006, Clostridium perfringens according to ISO/CD 6461-2:2002, somatic coliphages according to ISO 10705-1:2000, Campylobacter spp. by culture on CCDA agar (in-house method), Salmonella spp. according to ISO 6340:1995, Verotoxin-producing E. coli (VTEC) by PCR screening for vt genes and NoV by seminested PCR [22]. Additional water samples were collected on 17 September and analyzed for presence of NoV and coliphages. From the questionnaire survey it could be calculated that out of the 7500 inhabitant that lived in households supplied by drinking water from Lilla Edet WTP, about 2000 (26.7%) fell ill with acute gastroenteritis. NoV was detected in 33/50 stool samples collected from patients with symptoms of acute gastroenteritis. NoV strains of genogroup I (GI) predominated in 31 of these samples and mixed genotypes of GI infections occurred in ve samples, as described by Nenonen et al. [20]. Adenovirus was detected in one, sapovirus in one and rotavirus in three stool samples. Campylobacter spp. were isolated from two stool samples. In samples from the drinking water system in Lilla Edet collected on 12 September, E. coli, coliforms, enterococci, Giardia, Cryptosporidium, Clostridium, Campylobacter or NoV could not be detected, while faecal indicator bacteria and coliphages [300 plaque- forming units (p.f.u.)/100 ml] were found in raw water samples from the Gta lv river. However, somatic coliphages in concentrations between 4 and 42 p.f.u./100 ml were detected in samples from the drinking water system collected on 17 September and in samples from the raw water collected on the same date. In the Lilla Edet outbreak early detection of NoV strain diversity in stool samples strengthened the initial hypothesis that contaminated drinking water was the point source. Thus, the waterborne outbreak in Lilla Edet was most probably a consequence of the heavy faecal contamination of the raw water from Gta lv river [20].

What are the pathogens?

{'answer_start': [3119], 'text': ['NoV']}

Contamination Question Answering

A large waterborne outbreak of NoV occurred in Lilla Edet in Sweden in 2008. On 11 September 2008, the County Medical Ofcer (CMO) was informed about an unusually high number of individuals who had suddenly fallen ill with gastrointestinal symptoms during the previous days in Lilla Edet, a small municipality in southwest Sweden. Cases of gastroenteritis were reported from different places in the municipality, e.g. from the nursery schools, schools, nursing homes and from the Primary Healthcare Centre (PHC). The CMO notified the Environmental Office in the municipality about the ongoing outbreak. As the initial information indicated that drinking water was a possible source of the outbreak a boil water recommendation was issued on the same day. Investigations were initiated to identify the causative agents, the extent of the outbreak and possible sources of infection. Efforts were also made to inform the inhabitants in the municipality about the ongoing outbreak, the issued boil water recommendation, and medical advice for people with gastrointestinal symptoms. Information was spread via the media, the homepage of the municipality website, posters and local radio as VMA, i.e important message to the public. In addition to the cases reported from the municipality of Lilla Edet, the CMO was notified that 7/17 athletes of a team that had visited the municipality during the afternoon on 7 September had fallen ill with gastrointestinal symptoms 2 days after their visit. To estimate the proportion of the 13000 inhabitants in Lilla Edet that fell sick during the outbreak, questionnaires were sent by mail on 19 September to 1199 randomly selected inhabitants between the ages of 19 and 75 years. A case was defined as a household member with acute gastroenteritis with date of onset between 5 and 21 September. Fifty stool samples from outpatients with symptoms of acute gastroenteritis attending Lilla Edet PHC during 12-26 September were collected and examined for enteric pathogens, as described by Nenonen et al. [20]. Water samples, i.e. raw water from the Gta lv river, drinking water from different parts of the distribution network, and water from reservoirs in Lilla Edet, were collected on 12 September and analyzed at the microbiological laboratory at SMI for the presence of E. coli and coliform bacteria by Colilert 18 (IDEXX, USA), intestinal enterococci by Enterolert (IDEXX), (oo)cysts of Giardia spp. and Cryptosporidium spp. according to ISO 15553:2006, Clostridium perfringens according to ISO/CD 6461-2:2002, somatic coliphages according to ISO 10705-1:2000, Campylobacter spp. by culture on CCDA agar (in-house method), Salmonella spp. according to ISO 6340:1995, Verotoxin-producing E. coli (VTEC) by PCR screening for vt genes and NoV by seminested PCR [22]. Additional water samples were collected on 17 September and analyzed for presence of NoV and coliphages. From the questionnaire survey it could be calculated that out of the 7500 inhabitant that lived in households supplied by drinking water from Lilla Edet WTP, about 2000 (26.7%) fell ill with acute gastroenteritis. NoV was detected in 33/50 stool samples collected from patients with symptoms of acute gastroenteritis. NoV strains of genogroup I (GI) predominated in 31 of these samples and mixed genotypes of GI infections occurred in ve samples, as described by Nenonen et al. [20]. Adenovirus was detected in one, sapovirus in one and rotavirus in three stool samples. Campylobacter spp. were isolated from two stool samples. In samples from the drinking water system in Lilla Edet collected on 12 September, E. coli, coliforms, enterococci, Giardia, Cryptosporidium, Clostridium, Campylobacter or NoV could not be detected, while faecal indicator bacteria and coliphages [300 plaque- forming units (p.f.u.)/100 ml] were found in raw water samples from the Gta lv river. However, somatic coliphages in concentrations between 4 and 42 p.f.u./100 ml were detected in samples from the drinking water system collected on 17 September and in samples from the raw water collected on the same date. In the Lilla Edet outbreak early detection of NoV strain diversity in stool samples strengthened the initial hypothesis that contaminated drinking water was the point source. Thus, the waterborne outbreak in Lilla Edet was most probably a consequence of the heavy faecal contamination of the raw water from Gta lv river [20].

What is the concentration of the contaminant after analysis?

{'answer_start': [3780], 'text': ['300 plaque- forming units (p.f.u.)/100 ml']}

Contamination Question Answering

A large waterborne outbreak of NoV occurred in Lilla Edet in Sweden in 2008. On 11 September 2008, the County Medical Ofcer (CMO) was informed about an unusually high number of individuals who had suddenly fallen ill with gastrointestinal symptoms during the previous days in Lilla Edet, a small municipality in southwest Sweden. Cases of gastroenteritis were reported from different places in the municipality, e.g. from the nursery schools, schools, nursing homes and from the Primary Healthcare Centre (PHC). The CMO notified the Environmental Office in the municipality about the ongoing outbreak. As the initial information indicated that drinking water was a possible source of the outbreak a boil water recommendation was issued on the same day. Investigations were initiated to identify the causative agents, the extent of the outbreak and possible sources of infection. Efforts were also made to inform the inhabitants in the municipality about the ongoing outbreak, the issued boil water recommendation, and medical advice for people with gastrointestinal symptoms. Information was spread via the media, the homepage of the municipality website, posters and local radio as VMA, i.e important message to the public. In addition to the cases reported from the municipality of Lilla Edet, the CMO was notified that 7/17 athletes of a team that had visited the municipality during the afternoon on 7 September had fallen ill with gastrointestinal symptoms 2 days after their visit. To estimate the proportion of the 13000 inhabitants in Lilla Edet that fell sick during the outbreak, questionnaires were sent by mail on 19 September to 1199 randomly selected inhabitants between the ages of 19 and 75 years. A case was defined as a household member with acute gastroenteritis with date of onset between 5 and 21 September. Fifty stool samples from outpatients with symptoms of acute gastroenteritis attending Lilla Edet PHC during 12-26 September were collected and examined for enteric pathogens, as described by Nenonen et al. [20]. Water samples, i.e. raw water from the Gta lv river, drinking water from different parts of the distribution network, and water from reservoirs in Lilla Edet, were collected on 12 September and analyzed at the microbiological laboratory at SMI for the presence of E. coli and coliform bacteria by Colilert 18 (IDEXX, USA), intestinal enterococci by Enterolert (IDEXX), (oo)cysts of Giardia spp. and Cryptosporidium spp. according to ISO 15553:2006, Clostridium perfringens according to ISO/CD 6461-2:2002, somatic coliphages according to ISO 10705-1:2000, Campylobacter spp. by culture on CCDA agar (in-house method), Salmonella spp. according to ISO 6340:1995, Verotoxin-producing E. coli (VTEC) by PCR screening for vt genes and NoV by seminested PCR [22]. Additional water samples were collected on 17 September and analyzed for presence of NoV and coliphages. From the questionnaire survey it could be calculated that out of the 7500 inhabitant that lived in households supplied by drinking water from Lilla Edet WTP, about 2000 (26.7%) fell ill with acute gastroenteritis. NoV was detected in 33/50 stool samples collected from patients with symptoms of acute gastroenteritis. NoV strains of genogroup I (GI) predominated in 31 of these samples and mixed genotypes of GI infections occurred in ve samples, as described by Nenonen et al. [20]. Adenovirus was detected in one, sapovirus in one and rotavirus in three stool samples. Campylobacter spp. were isolated from two stool samples. In samples from the drinking water system in Lilla Edet collected on 12 September, E. coli, coliforms, enterococci, Giardia, Cryptosporidium, Clostridium, Campylobacter or NoV could not be detected, while faecal indicator bacteria and coliphages [300 plaque- forming units (p.f.u.)/100 ml] were found in raw water samples from the Gta lv river. However, somatic coliphages in concentrations between 4 and 42 p.f.u./100 ml were detected in samples from the drinking water system collected on 17 September and in samples from the raw water collected on the same date. In the Lilla Edet outbreak early detection of NoV strain diversity in stool samples strengthened the initial hypothesis that contaminated drinking water was the point source. Thus, the waterborne outbreak in Lilla Edet was most probably a consequence of the heavy faecal contamination of the raw water from Gta lv river [20].

What are the symptoms?

{'answer_start': [222], 'text': ['gastrointestinal']}

Contamination Question Answering

A large waterborne outbreak of NoV occurred in Lilla Edet in Sweden in 2008. On 11 September 2008, the County Medical Ofcer (CMO) was informed about an unusually high number of individuals who had suddenly fallen ill with gastrointestinal symptoms during the previous days in Lilla Edet, a small municipality in southwest Sweden. Cases of gastroenteritis were reported from different places in the municipality, e.g. from the nursery schools, schools, nursing homes and from the Primary Healthcare Centre (PHC). The CMO notified the Environmental Office in the municipality about the ongoing outbreak. As the initial information indicated that drinking water was a possible source of the outbreak a boil water recommendation was issued on the same day. Investigations were initiated to identify the causative agents, the extent of the outbreak and possible sources of infection. Efforts were also made to inform the inhabitants in the municipality about the ongoing outbreak, the issued boil water recommendation, and medical advice for people with gastrointestinal symptoms. Information was spread via the media, the homepage of the municipality website, posters and local radio as VMA, i.e important message to the public. In addition to the cases reported from the municipality of Lilla Edet, the CMO was notified that 7/17 athletes of a team that had visited the municipality during the afternoon on 7 September had fallen ill with gastrointestinal symptoms 2 days after their visit. To estimate the proportion of the 13000 inhabitants in Lilla Edet that fell sick during the outbreak, questionnaires were sent by mail on 19 September to 1199 randomly selected inhabitants between the ages of 19 and 75 years. A case was defined as a household member with acute gastroenteritis with date of onset between 5 and 21 September. Fifty stool samples from outpatients with symptoms of acute gastroenteritis attending Lilla Edet PHC during 12-26 September were collected and examined for enteric pathogens, as described by Nenonen et al. [20]. Water samples, i.e. raw water from the Gta lv river, drinking water from different parts of the distribution network, and water from reservoirs in Lilla Edet, were collected on 12 September and analyzed at the microbiological laboratory at SMI for the presence of E. coli and coliform bacteria by Colilert 18 (IDEXX, USA), intestinal enterococci by Enterolert (IDEXX), (oo)cysts of Giardia spp. and Cryptosporidium spp. according to ISO 15553:2006, Clostridium perfringens according to ISO/CD 6461-2:2002, somatic coliphages according to ISO 10705-1:2000, Campylobacter spp. by culture on CCDA agar (in-house method), Salmonella spp. according to ISO 6340:1995, Verotoxin-producing E. coli (VTEC) by PCR screening for vt genes and NoV by seminested PCR [22]. Additional water samples were collected on 17 September and analyzed for presence of NoV and coliphages. From the questionnaire survey it could be calculated that out of the 7500 inhabitant that lived in households supplied by drinking water from Lilla Edet WTP, about 2000 (26.7%) fell ill with acute gastroenteritis. NoV was detected in 33/50 stool samples collected from patients with symptoms of acute gastroenteritis. NoV strains of genogroup I (GI) predominated in 31 of these samples and mixed genotypes of GI infections occurred in ve samples, as described by Nenonen et al. [20]. Adenovirus was detected in one, sapovirus in one and rotavirus in three stool samples. Campylobacter spp. were isolated from two stool samples. In samples from the drinking water system in Lilla Edet collected on 12 September, E. coli, coliforms, enterococci, Giardia, Cryptosporidium, Clostridium, Campylobacter or NoV could not be detected, while faecal indicator bacteria and coliphages [300 plaque- forming units (p.f.u.)/100 ml] were found in raw water samples from the Gta lv river. However, somatic coliphages in concentrations between 4 and 42 p.f.u./100 ml were detected in samples from the drinking water system collected on 17 September and in samples from the raw water collected on the same date. In the Lilla Edet outbreak early detection of NoV strain diversity in stool samples strengthened the initial hypothesis that contaminated drinking water was the point source. Thus, the waterborne outbreak in Lilla Edet was most probably a consequence of the heavy faecal contamination of the raw water from Gta lv river [20].

What is the concentration of the pathogen?

{'answer_start': [3924], 'text': ['between 4 and 42 p.f.u./100 ml']}

Contamination Question Answering

A large waterborne outbreak of NoV occurred in Lilla Edet in Sweden in 2008. On 11 September 2008, the County Medical Ofcer (CMO) was informed about an unusually high number of individuals who had suddenly fallen ill with gastrointestinal symptoms during the previous days in Lilla Edet, a small municipality in southwest Sweden. Cases of gastroenteritis were reported from different places in the municipality, e.g. from the nursery schools, schools, nursing homes and from the Primary Healthcare Centre (PHC). The CMO notified the Environmental Office in the municipality about the ongoing outbreak. As the initial information indicated that drinking water was a possible source of the outbreak a boil water recommendation was issued on the same day. Investigations were initiated to identify the causative agents, the extent of the outbreak and possible sources of infection. Efforts were also made to inform the inhabitants in the municipality about the ongoing outbreak, the issued boil water recommendation, and medical advice for people with gastrointestinal symptoms. Information was spread via the media, the homepage of the municipality website, posters and local radio as VMA, i.e important message to the public. In addition to the cases reported from the municipality of Lilla Edet, the CMO was notified that 7/17 athletes of a team that had visited the municipality during the afternoon on 7 September had fallen ill with gastrointestinal symptoms 2 days after their visit. To estimate the proportion of the 13000 inhabitants in Lilla Edet that fell sick during the outbreak, questionnaires were sent by mail on 19 September to 1199 randomly selected inhabitants between the ages of 19 and 75 years. A case was defined as a household member with acute gastroenteritis with date of onset between 5 and 21 September. Fifty stool samples from outpatients with symptoms of acute gastroenteritis attending Lilla Edet PHC during 12-26 September were collected and examined for enteric pathogens, as described by Nenonen et al. [20]. Water samples, i.e. raw water from the Gta lv river, drinking water from different parts of the distribution network, and water from reservoirs in Lilla Edet, were collected on 12 September and analyzed at the microbiological laboratory at SMI for the presence of E. coli and coliform bacteria by Colilert 18 (IDEXX, USA), intestinal enterococci by Enterolert (IDEXX), (oo)cysts of Giardia spp. and Cryptosporidium spp. according to ISO 15553:2006, Clostridium perfringens according to ISO/CD 6461-2:2002, somatic coliphages according to ISO 10705-1:2000, Campylobacter spp. by culture on CCDA agar (in-house method), Salmonella spp. according to ISO 6340:1995, Verotoxin-producing E. coli (VTEC) by PCR screening for vt genes and NoV by seminested PCR [22]. Additional water samples were collected on 17 September and analyzed for presence of NoV and coliphages. From the questionnaire survey it could be calculated that out of the 7500 inhabitant that lived in households supplied by drinking water from Lilla Edet WTP, about 2000 (26.7%) fell ill with acute gastroenteritis. NoV was detected in 33/50 stool samples collected from patients with symptoms of acute gastroenteritis. NoV strains of genogroup I (GI) predominated in 31 of these samples and mixed genotypes of GI infections occurred in ve samples, as described by Nenonen et al. [20]. Adenovirus was detected in one, sapovirus in one and rotavirus in three stool samples. Campylobacter spp. were isolated from two stool samples. In samples from the drinking water system in Lilla Edet collected on 12 September, E. coli, coliforms, enterococci, Giardia, Cryptosporidium, Clostridium, Campylobacter or NoV could not be detected, while faecal indicator bacteria and coliphages [300 plaque- forming units (p.f.u.)/100 ml] were found in raw water samples from the Gta lv river. However, somatic coliphages in concentrations between 4 and 42 p.f.u./100 ml were detected in samples from the drinking water system collected on 17 September and in samples from the raw water collected on the same date. In the Lilla Edet outbreak early detection of NoV strain diversity in stool samples strengthened the initial hypothesis that contaminated drinking water was the point source. Thus, the waterborne outbreak in Lilla Edet was most probably a consequence of the heavy faecal contamination of the raw water from Gta lv river [20].

What is the event?

{'answer_start': [8], 'text': ['waterborne outbreak of NoV']}

Contamination Question Answering

A large waterborne outbreak of NoV occurred in Lilla Edet in Sweden in 2008. On 11 September 2008, the County Medical Ofcer (CMO) was informed about an unusually high number of individuals who had suddenly fallen ill with gastrointestinal symptoms during the previous days in Lilla Edet, a small municipality in southwest Sweden. Cases of gastroenteritis were reported from different places in the municipality, e.g. from the nursery schools, schools, nursing homes and from the Primary Healthcare Centre (PHC). The CMO notified the Environmental Office in the municipality about the ongoing outbreak. As the initial information indicated that drinking water was a possible source of the outbreak a boil water recommendation was issued on the same day. Investigations were initiated to identify the causative agents, the extent of the outbreak and possible sources of infection. Efforts were also made to inform the inhabitants in the municipality about the ongoing outbreak, the issued boil water recommendation, and medical advice for people with gastrointestinal symptoms. Information was spread via the media, the homepage of the municipality website, posters and local radio as VMA, i.e important message to the public. In addition to the cases reported from the municipality of Lilla Edet, the CMO was notified that 7/17 athletes of a team that had visited the municipality during the afternoon on 7 September had fallen ill with gastrointestinal symptoms 2 days after their visit. To estimate the proportion of the 13000 inhabitants in Lilla Edet that fell sick during the outbreak, questionnaires were sent by mail on 19 September to 1199 randomly selected inhabitants between the ages of 19 and 75 years. A case was defined as a household member with acute gastroenteritis with date of onset between 5 and 21 September. Fifty stool samples from outpatients with symptoms of acute gastroenteritis attending Lilla Edet PHC during 12-26 September were collected and examined for enteric pathogens, as described by Nenonen et al. [20]. Water samples, i.e. raw water from the Gta lv river, drinking water from different parts of the distribution network, and water from reservoirs in Lilla Edet, were collected on 12 September and analyzed at the microbiological laboratory at SMI for the presence of E. coli and coliform bacteria by Colilert 18 (IDEXX, USA), intestinal enterococci by Enterolert (IDEXX), (oo)cysts of Giardia spp. and Cryptosporidium spp. according to ISO 15553:2006, Clostridium perfringens according to ISO/CD 6461-2:2002, somatic coliphages according to ISO 10705-1:2000, Campylobacter spp. by culture on CCDA agar (in-house method), Salmonella spp. according to ISO 6340:1995, Verotoxin-producing E. coli (VTEC) by PCR screening for vt genes and NoV by seminested PCR [22]. Additional water samples were collected on 17 September and analyzed for presence of NoV and coliphages. From the questionnaire survey it could be calculated that out of the 7500 inhabitant that lived in households supplied by drinking water from Lilla Edet WTP, about 2000 (26.7%) fell ill with acute gastroenteritis. NoV was detected in 33/50 stool samples collected from patients with symptoms of acute gastroenteritis. NoV strains of genogroup I (GI) predominated in 31 of these samples and mixed genotypes of GI infections occurred in ve samples, as described by Nenonen et al. [20]. Adenovirus was detected in one, sapovirus in one and rotavirus in three stool samples. Campylobacter spp. were isolated from two stool samples. In samples from the drinking water system in Lilla Edet collected on 12 September, E. coli, coliforms, enterococci, Giardia, Cryptosporidium, Clostridium, Campylobacter or NoV could not be detected, while faecal indicator bacteria and coliphages [300 plaque- forming units (p.f.u.)/100 ml] were found in raw water samples from the Gta lv river. However, somatic coliphages in concentrations between 4 and 42 p.f.u./100 ml were detected in samples from the drinking water system collected on 17 September and in samples from the raw water collected on the same date. In the Lilla Edet outbreak early detection of NoV strain diversity in stool samples strengthened the initial hypothesis that contaminated drinking water was the point source. Thus, the waterborne outbreak in Lilla Edet was most probably a consequence of the heavy faecal contamination of the raw water from Gta lv river [20].

What are the initial steps of investigation?

{'answer_start': [786], 'text': ['identify the causative agents']}

Contamination Question Answering

A large waterborne outbreak of NoV occurred in Lilla Edet in Sweden in 2008. On 11 September 2008, the County Medical Ofcer (CMO) was informed about an unusually high number of individuals who had suddenly fallen ill with gastrointestinal symptoms during the previous days in Lilla Edet, a small municipality in southwest Sweden. Cases of gastroenteritis were reported from different places in the municipality, e.g. from the nursery schools, schools, nursing homes and from the Primary Healthcare Centre (PHC). The CMO notified the Environmental Office in the municipality about the ongoing outbreak. As the initial information indicated that drinking water was a possible source of the outbreak a boil water recommendation was issued on the same day. Investigations were initiated to identify the causative agents, the extent of the outbreak and possible sources of infection. Efforts were also made to inform the inhabitants in the municipality about the ongoing outbreak, the issued boil water recommendation, and medical advice for people with gastrointestinal symptoms. Information was spread via the media, the homepage of the municipality website, posters and local radio as VMA, i.e important message to the public. In addition to the cases reported from the municipality of Lilla Edet, the CMO was notified that 7/17 athletes of a team that had visited the municipality during the afternoon on 7 September had fallen ill with gastrointestinal symptoms 2 days after their visit. To estimate the proportion of the 13000 inhabitants in Lilla Edet that fell sick during the outbreak, questionnaires were sent by mail on 19 September to 1199 randomly selected inhabitants between the ages of 19 and 75 years. A case was defined as a household member with acute gastroenteritis with date of onset between 5 and 21 September. Fifty stool samples from outpatients with symptoms of acute gastroenteritis attending Lilla Edet PHC during 12-26 September were collected and examined for enteric pathogens, as described by Nenonen et al. [20]. Water samples, i.e. raw water from the Gta lv river, drinking water from different parts of the distribution network, and water from reservoirs in Lilla Edet, were collected on 12 September and analyzed at the microbiological laboratory at SMI for the presence of E. coli and coliform bacteria by Colilert 18 (IDEXX, USA), intestinal enterococci by Enterolert (IDEXX), (oo)cysts of Giardia spp. and Cryptosporidium spp. according to ISO 15553:2006, Clostridium perfringens according to ISO/CD 6461-2:2002, somatic coliphages according to ISO 10705-1:2000, Campylobacter spp. by culture on CCDA agar (in-house method), Salmonella spp. according to ISO 6340:1995, Verotoxin-producing E. coli (VTEC) by PCR screening for vt genes and NoV by seminested PCR [22]. Additional water samples were collected on 17 September and analyzed for presence of NoV and coliphages. From the questionnaire survey it could be calculated that out of the 7500 inhabitant that lived in households supplied by drinking water from Lilla Edet WTP, about 2000 (26.7%) fell ill with acute gastroenteritis. NoV was detected in 33/50 stool samples collected from patients with symptoms of acute gastroenteritis. NoV strains of genogroup I (GI) predominated in 31 of these samples and mixed genotypes of GI infections occurred in ve samples, as described by Nenonen et al. [20]. Adenovirus was detected in one, sapovirus in one and rotavirus in three stool samples. Campylobacter spp. were isolated from two stool samples. In samples from the drinking water system in Lilla Edet collected on 12 September, E. coli, coliforms, enterococci, Giardia, Cryptosporidium, Clostridium, Campylobacter or NoV could not be detected, while faecal indicator bacteria and coliphages [300 plaque- forming units (p.f.u.)/100 ml] were found in raw water samples from the Gta lv river. However, somatic coliphages in concentrations between 4 and 42 p.f.u./100 ml were detected in samples from the drinking water system collected on 17 September and in samples from the raw water collected on the same date. In the Lilla Edet outbreak early detection of NoV strain diversity in stool samples strengthened the initial hypothesis that contaminated drinking water was the point source. Thus, the waterborne outbreak in Lilla Edet was most probably a consequence of the heavy faecal contamination of the raw water from Gta lv river [20].

What are the first steps of mitigation?

{'answer_start': [699], 'text': ['boil water']}

Contamination Question Answering

A large waterborne outbreak of NoV occurred in Lilla Edet in Sweden in 2008. On 11 September 2008, the County Medical Ofcer (CMO) was informed about an unusually high number of individuals who had suddenly fallen ill with gastrointestinal symptoms during the previous days in Lilla Edet, a small municipality in southwest Sweden. Cases of gastroenteritis were reported from different places in the municipality, e.g. from the nursery schools, schools, nursing homes and from the Primary Healthcare Centre (PHC). The CMO notified the Environmental Office in the municipality about the ongoing outbreak. As the initial information indicated that drinking water was a possible source of the outbreak a boil water recommendation was issued on the same day. Investigations were initiated to identify the causative agents, the extent of the outbreak and possible sources of infection. Efforts were also made to inform the inhabitants in the municipality about the ongoing outbreak, the issued boil water recommendation, and medical advice for people with gastrointestinal symptoms. Information was spread via the media, the homepage of the municipality website, posters and local radio as VMA, i.e important message to the public. In addition to the cases reported from the municipality of Lilla Edet, the CMO was notified that 7/17 athletes of a team that had visited the municipality during the afternoon on 7 September had fallen ill with gastrointestinal symptoms 2 days after their visit. To estimate the proportion of the 13000 inhabitants in Lilla Edet that fell sick during the outbreak, questionnaires were sent by mail on 19 September to 1199 randomly selected inhabitants between the ages of 19 and 75 years. A case was defined as a household member with acute gastroenteritis with date of onset between 5 and 21 September. Fifty stool samples from outpatients with symptoms of acute gastroenteritis attending Lilla Edet PHC during 12-26 September were collected and examined for enteric pathogens, as described by Nenonen et al. [20]. Water samples, i.e. raw water from the Gta lv river, drinking water from different parts of the distribution network, and water from reservoirs in Lilla Edet, were collected on 12 September and analyzed at the microbiological laboratory at SMI for the presence of E. coli and coliform bacteria by Colilert 18 (IDEXX, USA), intestinal enterococci by Enterolert (IDEXX), (oo)cysts of Giardia spp. and Cryptosporidium spp. according to ISO 15553:2006, Clostridium perfringens according to ISO/CD 6461-2:2002, somatic coliphages according to ISO 10705-1:2000, Campylobacter spp. by culture on CCDA agar (in-house method), Salmonella spp. according to ISO 6340:1995, Verotoxin-producing E. coli (VTEC) by PCR screening for vt genes and NoV by seminested PCR [22]. Additional water samples were collected on 17 September and analyzed for presence of NoV and coliphages. From the questionnaire survey it could be calculated that out of the 7500 inhabitant that lived in households supplied by drinking water from Lilla Edet WTP, about 2000 (26.7%) fell ill with acute gastroenteritis. NoV was detected in 33/50 stool samples collected from patients with symptoms of acute gastroenteritis. NoV strains of genogroup I (GI) predominated in 31 of these samples and mixed genotypes of GI infections occurred in ve samples, as described by Nenonen et al. [20]. Adenovirus was detected in one, sapovirus in one and rotavirus in three stool samples. Campylobacter spp. were isolated from two stool samples. In samples from the drinking water system in Lilla Edet collected on 12 September, E. coli, coliforms, enterococci, Giardia, Cryptosporidium, Clostridium, Campylobacter or NoV could not be detected, while faecal indicator bacteria and coliphages [300 plaque- forming units (p.f.u.)/100 ml] were found in raw water samples from the Gta lv river. However, somatic coliphages in concentrations between 4 and 42 p.f.u./100 ml were detected in samples from the drinking water system collected on 17 September and in samples from the raw water collected on the same date. In the Lilla Edet outbreak early detection of NoV strain diversity in stool samples strengthened the initial hypothesis that contaminated drinking water was the point source. Thus, the waterborne outbreak in Lilla Edet was most probably a consequence of the heavy faecal contamination of the raw water from Gta lv river [20].

What type of samples were examined?

{'answer_start': [2041], 'text': ['Water samples']}

Contamination Question Answering

A large waterborne outbreak of NoV occurred in Lilla Edet in Sweden in 2008. On 11 September 2008, the County Medical Ofcer (CMO) was informed about an unusually high number of individuals who had suddenly fallen ill with gastrointestinal symptoms during the previous days in Lilla Edet, a small municipality in southwest Sweden. Cases of gastroenteritis were reported from different places in the municipality, e.g. from the nursery schools, schools, nursing homes and from the Primary Healthcare Centre (PHC). The CMO notified the Environmental Office in the municipality about the ongoing outbreak. As the initial information indicated that drinking water was a possible source of the outbreak a boil water recommendation was issued on the same day. Investigations were initiated to identify the causative agents, the extent of the outbreak and possible sources of infection. Efforts were also made to inform the inhabitants in the municipality about the ongoing outbreak, the issued boil water recommendation, and medical advice for people with gastrointestinal symptoms. Information was spread via the media, the homepage of the municipality website, posters and local radio as VMA, i.e important message to the public. In addition to the cases reported from the municipality of Lilla Edet, the CMO was notified that 7/17 athletes of a team that had visited the municipality during the afternoon on 7 September had fallen ill with gastrointestinal symptoms 2 days after their visit. To estimate the proportion of the 13000 inhabitants in Lilla Edet that fell sick during the outbreak, questionnaires were sent by mail on 19 September to 1199 randomly selected inhabitants between the ages of 19 and 75 years. A case was defined as a household member with acute gastroenteritis with date of onset between 5 and 21 September. Fifty stool samples from outpatients with symptoms of acute gastroenteritis attending Lilla Edet PHC during 12-26 September were collected and examined for enteric pathogens, as described by Nenonen et al. [20]. Water samples, i.e. raw water from the Gta lv river, drinking water from different parts of the distribution network, and water from reservoirs in Lilla Edet, were collected on 12 September and analyzed at the microbiological laboratory at SMI for the presence of E. coli and coliform bacteria by Colilert 18 (IDEXX, USA), intestinal enterococci by Enterolert (IDEXX), (oo)cysts of Giardia spp. and Cryptosporidium spp. according to ISO 15553:2006, Clostridium perfringens according to ISO/CD 6461-2:2002, somatic coliphages according to ISO 10705-1:2000, Campylobacter spp. by culture on CCDA agar (in-house method), Salmonella spp. according to ISO 6340:1995, Verotoxin-producing E. coli (VTEC) by PCR screening for vt genes and NoV by seminested PCR [22]. Additional water samples were collected on 17 September and analyzed for presence of NoV and coliphages. From the questionnaire survey it could be calculated that out of the 7500 inhabitant that lived in households supplied by drinking water from Lilla Edet WTP, about 2000 (26.7%) fell ill with acute gastroenteritis. NoV was detected in 33/50 stool samples collected from patients with symptoms of acute gastroenteritis. NoV strains of genogroup I (GI) predominated in 31 of these samples and mixed genotypes of GI infections occurred in ve samples, as described by Nenonen et al. [20]. Adenovirus was detected in one, sapovirus in one and rotavirus in three stool samples. Campylobacter spp. were isolated from two stool samples. In samples from the drinking water system in Lilla Edet collected on 12 September, E. coli, coliforms, enterococci, Giardia, Cryptosporidium, Clostridium, Campylobacter or NoV could not be detected, while faecal indicator bacteria and coliphages [300 plaque- forming units (p.f.u.)/100 ml] were found in raw water samples from the Gta lv river. However, somatic coliphages in concentrations between 4 and 42 p.f.u./100 ml were detected in samples from the drinking water system collected on 17 September and in samples from the raw water collected on the same date. In the Lilla Edet outbreak early detection of NoV strain diversity in stool samples strengthened the initial hypothesis that contaminated drinking water was the point source. Thus, the waterborne outbreak in Lilla Edet was most probably a consequence of the heavy faecal contamination of the raw water from Gta lv river [20].

What did the authorities do to mitigate the event?

{'answer_start': [905], 'text': ['inform the inhabitants']}

Contamination Question Answering

A large waterborne outbreak of NoV occurred in Lilla Edet in Sweden in 2008. On 11 September 2008, the County Medical Ofcer (CMO) was informed about an unusually high number of individuals who had suddenly fallen ill with gastrointestinal symptoms during the previous days in Lilla Edet, a small municipality in southwest Sweden. Cases of gastroenteritis were reported from different places in the municipality, e.g. from the nursery schools, schools, nursing homes and from the Primary Healthcare Centre (PHC). The CMO notified the Environmental Office in the municipality about the ongoing outbreak. As the initial information indicated that drinking water was a possible source of the outbreak a boil water recommendation was issued on the same day. Investigations were initiated to identify the causative agents, the extent of the outbreak and possible sources of infection. Efforts were also made to inform the inhabitants in the municipality about the ongoing outbreak, the issued boil water recommendation, and medical advice for people with gastrointestinal symptoms. Information was spread via the media, the homepage of the municipality website, posters and local radio as VMA, i.e important message to the public. In addition to the cases reported from the municipality of Lilla Edet, the CMO was notified that 7/17 athletes of a team that had visited the municipality during the afternoon on 7 September had fallen ill with gastrointestinal symptoms 2 days after their visit. To estimate the proportion of the 13000 inhabitants in Lilla Edet that fell sick during the outbreak, questionnaires were sent by mail on 19 September to 1199 randomly selected inhabitants between the ages of 19 and 75 years. A case was defined as a household member with acute gastroenteritis with date of onset between 5 and 21 September. Fifty stool samples from outpatients with symptoms of acute gastroenteritis attending Lilla Edet PHC during 12-26 September were collected and examined for enteric pathogens, as described by Nenonen et al. [20]. Water samples, i.e. raw water from the Gta lv river, drinking water from different parts of the distribution network, and water from reservoirs in Lilla Edet, were collected on 12 September and analyzed at the microbiological laboratory at SMI for the presence of E. coli and coliform bacteria by Colilert 18 (IDEXX, USA), intestinal enterococci by Enterolert (IDEXX), (oo)cysts of Giardia spp. and Cryptosporidium spp. according to ISO 15553:2006, Clostridium perfringens according to ISO/CD 6461-2:2002, somatic coliphages according to ISO 10705-1:2000, Campylobacter spp. by culture on CCDA agar (in-house method), Salmonella spp. according to ISO 6340:1995, Verotoxin-producing E. coli (VTEC) by PCR screening for vt genes and NoV by seminested PCR [22]. Additional water samples were collected on 17 September and analyzed for presence of NoV and coliphages. From the questionnaire survey it could be calculated that out of the 7500 inhabitant that lived in households supplied by drinking water from Lilla Edet WTP, about 2000 (26.7%) fell ill with acute gastroenteritis. NoV was detected in 33/50 stool samples collected from patients with symptoms of acute gastroenteritis. NoV strains of genogroup I (GI) predominated in 31 of these samples and mixed genotypes of GI infections occurred in ve samples, as described by Nenonen et al. [20]. Adenovirus was detected in one, sapovirus in one and rotavirus in three stool samples. Campylobacter spp. were isolated from two stool samples. In samples from the drinking water system in Lilla Edet collected on 12 September, E. coli, coliforms, enterococci, Giardia, Cryptosporidium, Clostridium, Campylobacter or NoV could not be detected, while faecal indicator bacteria and coliphages [300 plaque- forming units (p.f.u.)/100 ml] were found in raw water samples from the Gta lv river. However, somatic coliphages in concentrations between 4 and 42 p.f.u./100 ml were detected in samples from the drinking water system collected on 17 September and in samples from the raw water collected on the same date. In the Lilla Edet outbreak early detection of NoV strain diversity in stool samples strengthened the initial hypothesis that contaminated drinking water was the point source. Thus, the waterborne outbreak in Lilla Edet was most probably a consequence of the heavy faecal contamination of the raw water from Gta lv river [20].

What was the age of the affected people?

{'answer_start': [1697], 'text': ['19 and 75 years']}

Contamination Question Answering

A large waterborne outbreak of NoV occurred in Lilla Edet in Sweden in 2008. On 11 September 2008, the County Medical Ofcer (CMO) was informed about an unusually high number of individuals who had suddenly fallen ill with gastrointestinal symptoms during the previous days in Lilla Edet, a small municipality in southwest Sweden. Cases of gastroenteritis were reported from different places in the municipality, e.g. from the nursery schools, schools, nursing homes and from the Primary Healthcare Centre (PHC). The CMO notified the Environmental Office in the municipality about the ongoing outbreak. As the initial information indicated that drinking water was a possible source of the outbreak a boil water recommendation was issued on the same day. Investigations were initiated to identify the causative agents, the extent of the outbreak and possible sources of infection. Efforts were also made to inform the inhabitants in the municipality about the ongoing outbreak, the issued boil water recommendation, and medical advice for people with gastrointestinal symptoms. Information was spread via the media, the homepage of the municipality website, posters and local radio as VMA, i.e important message to the public. In addition to the cases reported from the municipality of Lilla Edet, the CMO was notified that 7/17 athletes of a team that had visited the municipality during the afternoon on 7 September had fallen ill with gastrointestinal symptoms 2 days after their visit. To estimate the proportion of the 13000 inhabitants in Lilla Edet that fell sick during the outbreak, questionnaires were sent by mail on 19 September to 1199 randomly selected inhabitants between the ages of 19 and 75 years. A case was defined as a household member with acute gastroenteritis with date of onset between 5 and 21 September. Fifty stool samples from outpatients with symptoms of acute gastroenteritis attending Lilla Edet PHC during 12-26 September were collected and examined for enteric pathogens, as described by Nenonen et al. [20]. Water samples, i.e. raw water from the Gta lv river, drinking water from different parts of the distribution network, and water from reservoirs in Lilla Edet, were collected on 12 September and analyzed at the microbiological laboratory at SMI for the presence of E. coli and coliform bacteria by Colilert 18 (IDEXX, USA), intestinal enterococci by Enterolert (IDEXX), (oo)cysts of Giardia spp. and Cryptosporidium spp. according to ISO 15553:2006, Clostridium perfringens according to ISO/CD 6461-2:2002, somatic coliphages according to ISO 10705-1:2000, Campylobacter spp. by culture on CCDA agar (in-house method), Salmonella spp. according to ISO 6340:1995, Verotoxin-producing E. coli (VTEC) by PCR screening for vt genes and NoV by seminested PCR [22]. Additional water samples were collected on 17 September and analyzed for presence of NoV and coliphages. From the questionnaire survey it could be calculated that out of the 7500 inhabitant that lived in households supplied by drinking water from Lilla Edet WTP, about 2000 (26.7%) fell ill with acute gastroenteritis. NoV was detected in 33/50 stool samples collected from patients with symptoms of acute gastroenteritis. NoV strains of genogroup I (GI) predominated in 31 of these samples and mixed genotypes of GI infections occurred in ve samples, as described by Nenonen et al. [20]. Adenovirus was detected in one, sapovirus in one and rotavirus in three stool samples. Campylobacter spp. were isolated from two stool samples. In samples from the drinking water system in Lilla Edet collected on 12 September, E. coli, coliforms, enterococci, Giardia, Cryptosporidium, Clostridium, Campylobacter or NoV could not be detected, while faecal indicator bacteria and coliphages [300 plaque- forming units (p.f.u.)/100 ml] were found in raw water samples from the Gta lv river. However, somatic coliphages in concentrations between 4 and 42 p.f.u./100 ml were detected in samples from the drinking water system collected on 17 September and in samples from the raw water collected on the same date. In the Lilla Edet outbreak early detection of NoV strain diversity in stool samples strengthened the initial hypothesis that contaminated drinking water was the point source. Thus, the waterborne outbreak in Lilla Edet was most probably a consequence of the heavy faecal contamination of the raw water from Gta lv river [20].

What is the source of contamination?

{'answer_start': [644], 'text': ['drinking water']}

Contamination Question Answering

A large waterborne outbreak of NoV occurred in Lilla Edet in Sweden in 2008. On 11 September 2008, the County Medical Ofcer (CMO) was informed about an unusually high number of individuals who had suddenly fallen ill with gastrointestinal symptoms during the previous days in Lilla Edet, a small municipality in southwest Sweden. Cases of gastroenteritis were reported from different places in the municipality, e.g. from the nursery schools, schools, nursing homes and from the Primary Healthcare Centre (PHC). The CMO notified the Environmental Office in the municipality about the ongoing outbreak. As the initial information indicated that drinking water was a possible source of the outbreak a boil water recommendation was issued on the same day. Investigations were initiated to identify the causative agents, the extent of the outbreak and possible sources of infection. Efforts were also made to inform the inhabitants in the municipality about the ongoing outbreak, the issued boil water recommendation, and medical advice for people with gastrointestinal symptoms. Information was spread via the media, the homepage of the municipality website, posters and local radio as VMA, i.e important message to the public. In addition to the cases reported from the municipality of Lilla Edet, the CMO was notified that 7/17 athletes of a team that had visited the municipality during the afternoon on 7 September had fallen ill with gastrointestinal symptoms 2 days after their visit. To estimate the proportion of the 13000 inhabitants in Lilla Edet that fell sick during the outbreak, questionnaires were sent by mail on 19 September to 1199 randomly selected inhabitants between the ages of 19 and 75 years. A case was defined as a household member with acute gastroenteritis with date of onset between 5 and 21 September. Fifty stool samples from outpatients with symptoms of acute gastroenteritis attending Lilla Edet PHC during 12-26 September were collected and examined for enteric pathogens, as described by Nenonen et al. [20]. Water samples, i.e. raw water from the Gta lv river, drinking water from different parts of the distribution network, and water from reservoirs in Lilla Edet, were collected on 12 September and analyzed at the microbiological laboratory at SMI for the presence of E. coli and coliform bacteria by Colilert 18 (IDEXX, USA), intestinal enterococci by Enterolert (IDEXX), (oo)cysts of Giardia spp. and Cryptosporidium spp. according to ISO 15553:2006, Clostridium perfringens according to ISO/CD 6461-2:2002, somatic coliphages according to ISO 10705-1:2000, Campylobacter spp. by culture on CCDA agar (in-house method), Salmonella spp. according to ISO 6340:1995, Verotoxin-producing E. coli (VTEC) by PCR screening for vt genes and NoV by seminested PCR [22]. Additional water samples were collected on 17 September and analyzed for presence of NoV and coliphages. From the questionnaire survey it could be calculated that out of the 7500 inhabitant that lived in households supplied by drinking water from Lilla Edet WTP, about 2000 (26.7%) fell ill with acute gastroenteritis. NoV was detected in 33/50 stool samples collected from patients with symptoms of acute gastroenteritis. NoV strains of genogroup I (GI) predominated in 31 of these samples and mixed genotypes of GI infections occurred in ve samples, as described by Nenonen et al. [20]. Adenovirus was detected in one, sapovirus in one and rotavirus in three stool samples. Campylobacter spp. were isolated from two stool samples. In samples from the drinking water system in Lilla Edet collected on 12 September, E. coli, coliforms, enterococci, Giardia, Cryptosporidium, Clostridium, Campylobacter or NoV could not be detected, while faecal indicator bacteria and coliphages [300 plaque- forming units (p.f.u.)/100 ml] were found in raw water samples from the Gta lv river. However, somatic coliphages in concentrations between 4 and 42 p.f.u./100 ml were detected in samples from the drinking water system collected on 17 September and in samples from the raw water collected on the same date. In the Lilla Edet outbreak early detection of NoV strain diversity in stool samples strengthened the initial hypothesis that contaminated drinking water was the point source. Thus, the waterborne outbreak in Lilla Edet was most probably a consequence of the heavy faecal contamination of the raw water from Gta lv river [20].

What was the alert of the event?

{'answer_start': [1410], 'text': ['gastrointestinal symptoms']}

Contamination Question Answering

A large waterborne outbreak of NoV occurred in Lilla Edet in Sweden in 2008. On 11 September 2008, the County Medical Ofcer (CMO) was informed about an unusually high number of individuals who had suddenly fallen ill with gastrointestinal symptoms during the previous days in Lilla Edet, a small municipality in southwest Sweden. Cases of gastroenteritis were reported from different places in the municipality, e.g. from the nursery schools, schools, nursing homes and from the Primary Healthcare Centre (PHC). The CMO notified the Environmental Office in the municipality about the ongoing outbreak. As the initial information indicated that drinking water was a possible source of the outbreak a boil water recommendation was issued on the same day. Investigations were initiated to identify the causative agents, the extent of the outbreak and possible sources of infection. Efforts were also made to inform the inhabitants in the municipality about the ongoing outbreak, the issued boil water recommendation, and medical advice for people with gastrointestinal symptoms. Information was spread via the media, the homepage of the municipality website, posters and local radio as VMA, i.e important message to the public. In addition to the cases reported from the municipality of Lilla Edet, the CMO was notified that 7/17 athletes of a team that had visited the municipality during the afternoon on 7 September had fallen ill with gastrointestinal symptoms 2 days after their visit. To estimate the proportion of the 13000 inhabitants in Lilla Edet that fell sick during the outbreak, questionnaires were sent by mail on 19 September to 1199 randomly selected inhabitants between the ages of 19 and 75 years. A case was defined as a household member with acute gastroenteritis with date of onset between 5 and 21 September. Fifty stool samples from outpatients with symptoms of acute gastroenteritis attending Lilla Edet PHC during 12-26 September were collected and examined for enteric pathogens, as described by Nenonen et al. [20]. Water samples, i.e. raw water from the Gta lv river, drinking water from different parts of the distribution network, and water from reservoirs in Lilla Edet, were collected on 12 September and analyzed at the microbiological laboratory at SMI for the presence of E. coli and coliform bacteria by Colilert 18 (IDEXX, USA), intestinal enterococci by Enterolert (IDEXX), (oo)cysts of Giardia spp. and Cryptosporidium spp. according to ISO 15553:2006, Clostridium perfringens according to ISO/CD 6461-2:2002, somatic coliphages according to ISO 10705-1:2000, Campylobacter spp. by culture on CCDA agar (in-house method), Salmonella spp. according to ISO 6340:1995, Verotoxin-producing E. coli (VTEC) by PCR screening for vt genes and NoV by seminested PCR [22]. Additional water samples were collected on 17 September and analyzed for presence of NoV and coliphages. From the questionnaire survey it could be calculated that out of the 7500 inhabitant that lived in households supplied by drinking water from Lilla Edet WTP, about 2000 (26.7%) fell ill with acute gastroenteritis. NoV was detected in 33/50 stool samples collected from patients with symptoms of acute gastroenteritis. NoV strains of genogroup I (GI) predominated in 31 of these samples and mixed genotypes of GI infections occurred in ve samples, as described by Nenonen et al. [20]. Adenovirus was detected in one, sapovirus in one and rotavirus in three stool samples. Campylobacter spp. were isolated from two stool samples. In samples from the drinking water system in Lilla Edet collected on 12 September, E. coli, coliforms, enterococci, Giardia, Cryptosporidium, Clostridium, Campylobacter or NoV could not be detected, while faecal indicator bacteria and coliphages [300 plaque- forming units (p.f.u.)/100 ml] were found in raw water samples from the Gta lv river. However, somatic coliphages in concentrations between 4 and 42 p.f.u./100 ml were detected in samples from the drinking water system collected on 17 September and in samples from the raw water collected on the same date. In the Lilla Edet outbreak early detection of NoV strain diversity in stool samples strengthened the initial hypothesis that contaminated drinking water was the point source. Thus, the waterborne outbreak in Lilla Edet was most probably a consequence of the heavy faecal contamination of the raw water from Gta lv river [20].

What were the associated pathogens of concern?

{'answer_start': [3389], 'text': ['Adenovirus']}

Contamination Question Answering

An unexpected increase in gastroenteritis cases was reported by healthcare workers on the KwaZulu-Natal Coast, South Africa, January 2017 with >600 cases seen over a 3-week period. A case-control study was conducted to identify the source and risk factors associated with the outbreak so as to recommend control and prevention measures. Record review identified cases and controls and structured-telephonic interviews were conducted to obtain exposure history. Stool specimens were collected from 20 cases along with environmental samples and both screened for enteric pathogens. A reported sewage contamination event impacting the lagoon was the likely source with person-to-person spread perpetuating the outbreak. On 5 January 2017, the Outbreak Response Unit (ORU) of the National Institute for Communicable Diseases (NICD), SA, was alerted to a high number of persons falling ill with gastrointestinal symptoms (diarrhoea and/or vomiting) on the coast of KZN Province. The alert from health authorities in the KZN Province indicated that between 14 December 2016 and 5 January 2017, 690 people presented with gastrointestinal symptoms at a private hospital on the KZN south coast. Based on the available information at the time, which included local newspaper and online articles that reported a sewage spillage into a nearby lagoon; the investigating team hypothesised that contamination of a coastal lagoon could have led to the outbreak. The outbreak occurred within an urban community on the south coast of KZN Province during December 2016 and January 2017. A case-control study was conducted, with a case defined as a person of any age who presented to the private hospitals emergency department between 19 December 2016 and 6 January 2017 with an acute onset of diarrhoea and/or vomiting. Twenty acute phase stool specimens were collected from cases presenting to the hospital between 6 and 10 January 2017 and sent cooled to the Centre for Enteric Diseases (CED), NICD, for testing. Water samples were collected from the lagoon and a nearby wastewater treatment works discharge (final effluent), which drains into a river that flows into the lagoon (Fig. 1). A total of 311 cases and 126 controls were identified. The median age for the cases was 21 years (interquartile range 1040 years). The most common symptoms were vomiting (85%; 133/157), diarrhoea (73%; 115/157) and abdominal cramps (31%; 49/157). Of the 20 clinical specimens tested, 11 (55%) tested positive for NoV; nine were positive for NoV GI, while two were positive for NoV GII. Aeromonas, enterovirus and EPEC were also detected in one NoV GI-positive specimen and STEC in another NoV GI-positive specimen. Environmental samples The total coliform and thermotolerant (faecal) coliform counts in the lagoon water were 2.39* 10^4 and 9.5* 10^3 cfu/100 ml, respectively. The E. coli level was 1.93* 10^3 cfu/100 ml. These data support the hypothesis that the lagoon was the source of the outbreak among holiday-makers on the KZN Coast. The lagoon was reportedly contaminated by the wastewater treatment works effluent, which drained into the river flowing into the lagoon.

What type of samples were analyzed?

{'answer_start': [461], 'text': ['Stool specimens']}

Contamination Question Answering

An unexpected increase in gastroenteritis cases was reported by healthcare workers on the KwaZulu-Natal Coast, South Africa, January 2017 with >600 cases seen over a 3-week period. A case-control study was conducted to identify the source and risk factors associated with the outbreak so as to recommend control and prevention measures. Record review identified cases and controls and structured-telephonic interviews were conducted to obtain exposure history. Stool specimens were collected from 20 cases along with environmental samples and both screened for enteric pathogens. A reported sewage contamination event impacting the lagoon was the likely source with person-to-person spread perpetuating the outbreak. On 5 January 2017, the Outbreak Response Unit (ORU) of the National Institute for Communicable Diseases (NICD), SA, was alerted to a high number of persons falling ill with gastrointestinal symptoms (diarrhoea and/or vomiting) on the coast of KZN Province. The alert from health authorities in the KZN Province indicated that between 14 December 2016 and 5 January 2017, 690 people presented with gastrointestinal symptoms at a private hospital on the KZN south coast. Based on the available information at the time, which included local newspaper and online articles that reported a sewage spillage into a nearby lagoon; the investigating team hypothesised that contamination of a coastal lagoon could have led to the outbreak. The outbreak occurred within an urban community on the south coast of KZN Province during December 2016 and January 2017. A case-control study was conducted, with a case defined as a person of any age who presented to the private hospitals emergency department between 19 December 2016 and 6 January 2017 with an acute onset of diarrhoea and/or vomiting. Twenty acute phase stool specimens were collected from cases presenting to the hospital between 6 and 10 January 2017 and sent cooled to the Centre for Enteric Diseases (CED), NICD, for testing. Water samples were collected from the lagoon and a nearby wastewater treatment works discharge (final effluent), which drains into a river that flows into the lagoon (Fig. 1). A total of 311 cases and 126 controls were identified. The median age for the cases was 21 years (interquartile range 1040 years). The most common symptoms were vomiting (85%; 133/157), diarrhoea (73%; 115/157) and abdominal cramps (31%; 49/157). Of the 20 clinical specimens tested, 11 (55%) tested positive for NoV; nine were positive for NoV GI, while two were positive for NoV GII. Aeromonas, enterovirus and EPEC were also detected in one NoV GI-positive specimen and STEC in another NoV GI-positive specimen. Environmental samples The total coliform and thermotolerant (faecal) coliform counts in the lagoon water were 2.39* 10^4 and 9.5* 10^3 cfu/100 ml, respectively. The E. coli level was 1.93* 10^3 cfu/100 ml. These data support the hypothesis that the lagoon was the source of the outbreak among holiday-makers on the KZN Coast. The lagoon was reportedly contaminated by the wastewater treatment works effluent, which drained into the river flowing into the lagoon.

What caused the event?

{'answer_start': [1380], 'text': ['contamination of a coastal lagoon']}

Contamination Question Answering

An unexpected increase in gastroenteritis cases was reported by healthcare workers on the KwaZulu-Natal Coast, South Africa, January 2017 with >600 cases seen over a 3-week period. A case-control study was conducted to identify the source and risk factors associated with the outbreak so as to recommend control and prevention measures. Record review identified cases and controls and structured-telephonic interviews were conducted to obtain exposure history. Stool specimens were collected from 20 cases along with environmental samples and both screened for enteric pathogens. A reported sewage contamination event impacting the lagoon was the likely source with person-to-person spread perpetuating the outbreak. On 5 January 2017, the Outbreak Response Unit (ORU) of the National Institute for Communicable Diseases (NICD), SA, was alerted to a high number of persons falling ill with gastrointestinal symptoms (diarrhoea and/or vomiting) on the coast of KZN Province. The alert from health authorities in the KZN Province indicated that between 14 December 2016 and 5 January 2017, 690 people presented with gastrointestinal symptoms at a private hospital on the KZN south coast. Based on the available information at the time, which included local newspaper and online articles that reported a sewage spillage into a nearby lagoon; the investigating team hypothesised that contamination of a coastal lagoon could have led to the outbreak. The outbreak occurred within an urban community on the south coast of KZN Province during December 2016 and January 2017. A case-control study was conducted, with a case defined as a person of any age who presented to the private hospitals emergency department between 19 December 2016 and 6 January 2017 with an acute onset of diarrhoea and/or vomiting. Twenty acute phase stool specimens were collected from cases presenting to the hospital between 6 and 10 January 2017 and sent cooled to the Centre for Enteric Diseases (CED), NICD, for testing. Water samples were collected from the lagoon and a nearby wastewater treatment works discharge (final effluent), which drains into a river that flows into the lagoon (Fig. 1). A total of 311 cases and 126 controls were identified. The median age for the cases was 21 years (interquartile range 1040 years). The most common symptoms were vomiting (85%; 133/157), diarrhoea (73%; 115/157) and abdominal cramps (31%; 49/157). Of the 20 clinical specimens tested, 11 (55%) tested positive for NoV; nine were positive for NoV GI, while two were positive for NoV GII. Aeromonas, enterovirus and EPEC were also detected in one NoV GI-positive specimen and STEC in another NoV GI-positive specimen. Environmental samples The total coliform and thermotolerant (faecal) coliform counts in the lagoon water were 2.39* 10^4 and 9.5* 10^3 cfu/100 ml, respectively. The E. coli level was 1.93* 10^3 cfu/100 ml. These data support the hypothesis that the lagoon was the source of the outbreak among holiday-makers on the KZN Coast. The lagoon was reportedly contaminated by the wastewater treatment works effluent, which drained into the river flowing into the lagoon.

What symptoms did people report?

{'answer_start': [2333], 'text': ['vomiting , diarrhoea, and abdominal cramps']}

Contamination Question Answering

An unexpected increase in gastroenteritis cases was reported by healthcare workers on the KwaZulu-Natal Coast, South Africa, January 2017 with >600 cases seen over a 3-week period. A case-control study was conducted to identify the source and risk factors associated with the outbreak so as to recommend control and prevention measures. Record review identified cases and controls and structured-telephonic interviews were conducted to obtain exposure history. Stool specimens were collected from 20 cases along with environmental samples and both screened for enteric pathogens. A reported sewage contamination event impacting the lagoon was the likely source with person-to-person spread perpetuating the outbreak. On 5 January 2017, the Outbreak Response Unit (ORU) of the National Institute for Communicable Diseases (NICD), SA, was alerted to a high number of persons falling ill with gastrointestinal symptoms (diarrhoea and/or vomiting) on the coast of KZN Province. The alert from health authorities in the KZN Province indicated that between 14 December 2016 and 5 January 2017, 690 people presented with gastrointestinal symptoms at a private hospital on the KZN south coast. Based on the available information at the time, which included local newspaper and online articles that reported a sewage spillage into a nearby lagoon; the investigating team hypothesised that contamination of a coastal lagoon could have led to the outbreak. The outbreak occurred within an urban community on the south coast of KZN Province during December 2016 and January 2017. A case-control study was conducted, with a case defined as a person of any age who presented to the private hospitals emergency department between 19 December 2016 and 6 January 2017 with an acute onset of diarrhoea and/or vomiting. Twenty acute phase stool specimens were collected from cases presenting to the hospital between 6 and 10 January 2017 and sent cooled to the Centre for Enteric Diseases (CED), NICD, for testing. Water samples were collected from the lagoon and a nearby wastewater treatment works discharge (final effluent), which drains into a river that flows into the lagoon (Fig. 1). A total of 311 cases and 126 controls were identified. The median age for the cases was 21 years (interquartile range 1040 years). The most common symptoms were vomiting (85%; 133/157), diarrhoea (73%; 115/157) and abdominal cramps (31%; 49/157). Of the 20 clinical specimens tested, 11 (55%) tested positive for NoV; nine were positive for NoV GI, while two were positive for NoV GII. Aeromonas, enterovirus and EPEC were also detected in one NoV GI-positive specimen and STEC in another NoV GI-positive specimen. Environmental samples The total coliform and thermotolerant (faecal) coliform counts in the lagoon water were 2.39* 10^4 and 9.5* 10^3 cfu/100 ml, respectively. The E. coli level was 1.93* 10^3 cfu/100 ml. These data support the hypothesis that the lagoon was the source of the outbreak among holiday-makers on the KZN Coast. The lagoon was reportedly contaminated by the wastewater treatment works effluent, which drained into the river flowing into the lagoon.

What is the initial cause of the event?

{'answer_start': [591], 'text': ['sewage contamination event impacting the lagoon']}

Contamination Question Answering

An unexpected increase in gastroenteritis cases was reported by healthcare workers on the KwaZulu-Natal Coast, South Africa, January 2017 with >600 cases seen over a 3-week period. A case-control study was conducted to identify the source and risk factors associated with the outbreak so as to recommend control and prevention measures. Record review identified cases and controls and structured-telephonic interviews were conducted to obtain exposure history. Stool specimens were collected from 20 cases along with environmental samples and both screened for enteric pathogens. A reported sewage contamination event impacting the lagoon was the likely source with person-to-person spread perpetuating the outbreak. On 5 January 2017, the Outbreak Response Unit (ORU) of the National Institute for Communicable Diseases (NICD), SA, was alerted to a high number of persons falling ill with gastrointestinal symptoms (diarrhoea and/or vomiting) on the coast of KZN Province. The alert from health authorities in the KZN Province indicated that between 14 December 2016 and 5 January 2017, 690 people presented with gastrointestinal symptoms at a private hospital on the KZN south coast. Based on the available information at the time, which included local newspaper and online articles that reported a sewage spillage into a nearby lagoon; the investigating team hypothesised that contamination of a coastal lagoon could have led to the outbreak. The outbreak occurred within an urban community on the south coast of KZN Province during December 2016 and January 2017. A case-control study was conducted, with a case defined as a person of any age who presented to the private hospitals emergency department between 19 December 2016 and 6 January 2017 with an acute onset of diarrhoea and/or vomiting. Twenty acute phase stool specimens were collected from cases presenting to the hospital between 6 and 10 January 2017 and sent cooled to the Centre for Enteric Diseases (CED), NICD, for testing. Water samples were collected from the lagoon and a nearby wastewater treatment works discharge (final effluent), which drains into a river that flows into the lagoon (Fig. 1). A total of 311 cases and 126 controls were identified. The median age for the cases was 21 years (interquartile range 1040 years). The most common symptoms were vomiting (85%; 133/157), diarrhoea (73%; 115/157) and abdominal cramps (31%; 49/157). Of the 20 clinical specimens tested, 11 (55%) tested positive for NoV; nine were positive for NoV GI, while two were positive for NoV GII. Aeromonas, enterovirus and EPEC were also detected in one NoV GI-positive specimen and STEC in another NoV GI-positive specimen. Environmental samples The total coliform and thermotolerant (faecal) coliform counts in the lagoon water were 2.39* 10^4 and 9.5* 10^3 cfu/100 ml, respectively. The E. coli level was 1.93* 10^3 cfu/100 ml. These data support the hypothesis that the lagoon was the source of the outbreak among holiday-makers on the KZN Coast. The lagoon was reportedly contaminated by the wastewater treatment works effluent, which drained into the river flowing into the lagoon.

What is the date of the event?

{'answer_start': [125], 'text': ['January 2017']}

Contamination Question Answering

An unexpected increase in gastroenteritis cases was reported by healthcare workers on the KwaZulu-Natal Coast, South Africa, January 2017 with >600 cases seen over a 3-week period. A case-control study was conducted to identify the source and risk factors associated with the outbreak so as to recommend control and prevention measures. Record review identified cases and controls and structured-telephonic interviews were conducted to obtain exposure history. Stool specimens were collected from 20 cases along with environmental samples and both screened for enteric pathogens. A reported sewage contamination event impacting the lagoon was the likely source with person-to-person spread perpetuating the outbreak. On 5 January 2017, the Outbreak Response Unit (ORU) of the National Institute for Communicable Diseases (NICD), SA, was alerted to a high number of persons falling ill with gastrointestinal symptoms (diarrhoea and/or vomiting) on the coast of KZN Province. The alert from health authorities in the KZN Province indicated that between 14 December 2016 and 5 January 2017, 690 people presented with gastrointestinal symptoms at a private hospital on the KZN south coast. Based on the available information at the time, which included local newspaper and online articles that reported a sewage spillage into a nearby lagoon; the investigating team hypothesised that contamination of a coastal lagoon could have led to the outbreak. The outbreak occurred within an urban community on the south coast of KZN Province during December 2016 and January 2017. A case-control study was conducted, with a case defined as a person of any age who presented to the private hospitals emergency department between 19 December 2016 and 6 January 2017 with an acute onset of diarrhoea and/or vomiting. Twenty acute phase stool specimens were collected from cases presenting to the hospital between 6 and 10 January 2017 and sent cooled to the Centre for Enteric Diseases (CED), NICD, for testing. Water samples were collected from the lagoon and a nearby wastewater treatment works discharge (final effluent), which drains into a river that flows into the lagoon (Fig. 1). A total of 311 cases and 126 controls were identified. The median age for the cases was 21 years (interquartile range 1040 years). The most common symptoms were vomiting (85%; 133/157), diarrhoea (73%; 115/157) and abdominal cramps (31%; 49/157). Of the 20 clinical specimens tested, 11 (55%) tested positive for NoV; nine were positive for NoV GI, while two were positive for NoV GII. Aeromonas, enterovirus and EPEC were also detected in one NoV GI-positive specimen and STEC in another NoV GI-positive specimen. Environmental samples The total coliform and thermotolerant (faecal) coliform counts in the lagoon water were 2.39* 10^4 and 9.5* 10^3 cfu/100 ml, respectively. The E. coli level was 1.93* 10^3 cfu/100 ml. These data support the hypothesis that the lagoon was the source of the outbreak among holiday-makers on the KZN Coast. The lagoon was reportedly contaminated by the wastewater treatment works effluent, which drained into the river flowing into the lagoon.

What is the location of the event?

{'answer_start': [111], 'text': ['South Africa']}

Contamination Question Answering

An unexpected increase in gastroenteritis cases was reported by healthcare workers on the KwaZulu-Natal Coast, South Africa, January 2017 with >600 cases seen over a 3-week period. A case-control study was conducted to identify the source and risk factors associated with the outbreak so as to recommend control and prevention measures. Record review identified cases and controls and structured-telephonic interviews were conducted to obtain exposure history. Stool specimens were collected from 20 cases along with environmental samples and both screened for enteric pathogens. A reported sewage contamination event impacting the lagoon was the likely source with person-to-person spread perpetuating the outbreak. On 5 January 2017, the Outbreak Response Unit (ORU) of the National Institute for Communicable Diseases (NICD), SA, was alerted to a high number of persons falling ill with gastrointestinal symptoms (diarrhoea and/or vomiting) on the coast of KZN Province. The alert from health authorities in the KZN Province indicated that between 14 December 2016 and 5 January 2017, 690 people presented with gastrointestinal symptoms at a private hospital on the KZN south coast. Based on the available information at the time, which included local newspaper and online articles that reported a sewage spillage into a nearby lagoon; the investigating team hypothesised that contamination of a coastal lagoon could have led to the outbreak. The outbreak occurred within an urban community on the south coast of KZN Province during December 2016 and January 2017. A case-control study was conducted, with a case defined as a person of any age who presented to the private hospitals emergency department between 19 December 2016 and 6 January 2017 with an acute onset of diarrhoea and/or vomiting. Twenty acute phase stool specimens were collected from cases presenting to the hospital between 6 and 10 January 2017 and sent cooled to the Centre for Enteric Diseases (CED), NICD, for testing. Water samples were collected from the lagoon and a nearby wastewater treatment works discharge (final effluent), which drains into a river that flows into the lagoon (Fig. 1). A total of 311 cases and 126 controls were identified. The median age for the cases was 21 years (interquartile range 1040 years). The most common symptoms were vomiting (85%; 133/157), diarrhoea (73%; 115/157) and abdominal cramps (31%; 49/157). Of the 20 clinical specimens tested, 11 (55%) tested positive for NoV; nine were positive for NoV GI, while two were positive for NoV GII. Aeromonas, enterovirus and EPEC were also detected in one NoV GI-positive specimen and STEC in another NoV GI-positive specimen. Environmental samples The total coliform and thermotolerant (faecal) coliform counts in the lagoon water were 2.39* 10^4 and 9.5* 10^3 cfu/100 ml, respectively. The E. coli level was 1.93* 10^3 cfu/100 ml. These data support the hypothesis that the lagoon was the source of the outbreak among holiday-makers on the KZN Coast. The lagoon was reportedly contaminated by the wastewater treatment works effluent, which drained into the river flowing into the lagoon.

What pathogen was connected to the outbreak?

{'answer_start': [2558], 'text': ['Aeromonas, enterovirus and EPEC']}

Contamination Question Answering

An unexpected increase in gastroenteritis cases was reported by healthcare workers on the KwaZulu-Natal Coast, South Africa, January 2017 with >600 cases seen over a 3-week period. A case-control study was conducted to identify the source and risk factors associated with the outbreak so as to recommend control and prevention measures. Record review identified cases and controls and structured-telephonic interviews were conducted to obtain exposure history. Stool specimens were collected from 20 cases along with environmental samples and both screened for enteric pathogens. A reported sewage contamination event impacting the lagoon was the likely source with person-to-person spread perpetuating the outbreak. On 5 January 2017, the Outbreak Response Unit (ORU) of the National Institute for Communicable Diseases (NICD), SA, was alerted to a high number of persons falling ill with gastrointestinal symptoms (diarrhoea and/or vomiting) on the coast of KZN Province. The alert from health authorities in the KZN Province indicated that between 14 December 2016 and 5 January 2017, 690 people presented with gastrointestinal symptoms at a private hospital on the KZN south coast. Based on the available information at the time, which included local newspaper and online articles that reported a sewage spillage into a nearby lagoon; the investigating team hypothesised that contamination of a coastal lagoon could have led to the outbreak. The outbreak occurred within an urban community on the south coast of KZN Province during December 2016 and January 2017. A case-control study was conducted, with a case defined as a person of any age who presented to the private hospitals emergency department between 19 December 2016 and 6 January 2017 with an acute onset of diarrhoea and/or vomiting. Twenty acute phase stool specimens were collected from cases presenting to the hospital between 6 and 10 January 2017 and sent cooled to the Centre for Enteric Diseases (CED), NICD, for testing. Water samples were collected from the lagoon and a nearby wastewater treatment works discharge (final effluent), which drains into a river that flows into the lagoon (Fig. 1). A total of 311 cases and 126 controls were identified. The median age for the cases was 21 years (interquartile range 1040 years). The most common symptoms were vomiting (85%; 133/157), diarrhoea (73%; 115/157) and abdominal cramps (31%; 49/157). Of the 20 clinical specimens tested, 11 (55%) tested positive for NoV; nine were positive for NoV GI, while two were positive for NoV GII. Aeromonas, enterovirus and EPEC were also detected in one NoV GI-positive specimen and STEC in another NoV GI-positive specimen. Environmental samples The total coliform and thermotolerant (faecal) coliform counts in the lagoon water were 2.39* 10^4 and 9.5* 10^3 cfu/100 ml, respectively. The E. coli level was 1.93* 10^3 cfu/100 ml. These data support the hypothesis that the lagoon was the source of the outbreak among holiday-makers on the KZN Coast. The lagoon was reportedly contaminated by the wastewater treatment works effluent, which drained into the river flowing into the lagoon.

What is the source that started the event?

{'answer_start': [2936], 'text': ['lagoon']}

Contamination Question Answering

An unexpected increase in gastroenteritis cases was reported by healthcare workers on the KwaZulu-Natal Coast, South Africa, January 2017 with >600 cases seen over a 3-week period. A case-control study was conducted to identify the source and risk factors associated with the outbreak so as to recommend control and prevention measures. Record review identified cases and controls and structured-telephonic interviews were conducted to obtain exposure history. Stool specimens were collected from 20 cases along with environmental samples and both screened for enteric pathogens. A reported sewage contamination event impacting the lagoon was the likely source with person-to-person spread perpetuating the outbreak. On 5 January 2017, the Outbreak Response Unit (ORU) of the National Institute for Communicable Diseases (NICD), SA, was alerted to a high number of persons falling ill with gastrointestinal symptoms (diarrhoea and/or vomiting) on the coast of KZN Province. The alert from health authorities in the KZN Province indicated that between 14 December 2016 and 5 January 2017, 690 people presented with gastrointestinal symptoms at a private hospital on the KZN south coast. Based on the available information at the time, which included local newspaper and online articles that reported a sewage spillage into a nearby lagoon; the investigating team hypothesised that contamination of a coastal lagoon could have led to the outbreak. The outbreak occurred within an urban community on the south coast of KZN Province during December 2016 and January 2017. A case-control study was conducted, with a case defined as a person of any age who presented to the private hospitals emergency department between 19 December 2016 and 6 January 2017 with an acute onset of diarrhoea and/or vomiting. Twenty acute phase stool specimens were collected from cases presenting to the hospital between 6 and 10 January 2017 and sent cooled to the Centre for Enteric Diseases (CED), NICD, for testing. Water samples were collected from the lagoon and a nearby wastewater treatment works discharge (final effluent), which drains into a river that flows into the lagoon (Fig. 1). A total of 311 cases and 126 controls were identified. The median age for the cases was 21 years (interquartile range 1040 years). The most common symptoms were vomiting (85%; 133/157), diarrhoea (73%; 115/157) and abdominal cramps (31%; 49/157). Of the 20 clinical specimens tested, 11 (55%) tested positive for NoV; nine were positive for NoV GI, while two were positive for NoV GII. Aeromonas, enterovirus and EPEC were also detected in one NoV GI-positive specimen and STEC in another NoV GI-positive specimen. Environmental samples The total coliform and thermotolerant (faecal) coliform counts in the lagoon water were 2.39* 10^4 and 9.5* 10^3 cfu/100 ml, respectively. The E. coli level was 1.93* 10^3 cfu/100 ml. These data support the hypothesis that the lagoon was the source of the outbreak among holiday-makers on the KZN Coast. The lagoon was reportedly contaminated by the wastewater treatment works effluent, which drained into the river flowing into the lagoon.

How was the event first detected?

{'answer_start': [63], 'text': ['healthcare workers']}

Contamination Question Answering

An unexpected increase in gastroenteritis cases was reported by healthcare workers on the KwaZulu-Natal Coast, South Africa, January 2017 with >600 cases seen over a 3-week period. A case-control study was conducted to identify the source and risk factors associated with the outbreak so as to recommend control and prevention measures. Record review identified cases and controls and structured-telephonic interviews were conducted to obtain exposure history. Stool specimens were collected from 20 cases along with environmental samples and both screened for enteric pathogens. A reported sewage contamination event impacting the lagoon was the likely source with person-to-person spread perpetuating the outbreak. On 5 January 2017, the Outbreak Response Unit (ORU) of the National Institute for Communicable Diseases (NICD), SA, was alerted to a high number of persons falling ill with gastrointestinal symptoms (diarrhoea and/or vomiting) on the coast of KZN Province. The alert from health authorities in the KZN Province indicated that between 14 December 2016 and 5 January 2017, 690 people presented with gastrointestinal symptoms at a private hospital on the KZN south coast. Based on the available information at the time, which included local newspaper and online articles that reported a sewage spillage into a nearby lagoon; the investigating team hypothesised that contamination of a coastal lagoon could have led to the outbreak. The outbreak occurred within an urban community on the south coast of KZN Province during December 2016 and January 2017. A case-control study was conducted, with a case defined as a person of any age who presented to the private hospitals emergency department between 19 December 2016 and 6 January 2017 with an acute onset of diarrhoea and/or vomiting. Twenty acute phase stool specimens were collected from cases presenting to the hospital between 6 and 10 January 2017 and sent cooled to the Centre for Enteric Diseases (CED), NICD, for testing. Water samples were collected from the lagoon and a nearby wastewater treatment works discharge (final effluent), which drains into a river that flows into the lagoon (Fig. 1). A total of 311 cases and 126 controls were identified. The median age for the cases was 21 years (interquartile range 1040 years). The most common symptoms were vomiting (85%; 133/157), diarrhoea (73%; 115/157) and abdominal cramps (31%; 49/157). Of the 20 clinical specimens tested, 11 (55%) tested positive for NoV; nine were positive for NoV GI, while two were positive for NoV GII. Aeromonas, enterovirus and EPEC were also detected in one NoV GI-positive specimen and STEC in another NoV GI-positive specimen. Environmental samples The total coliform and thermotolerant (faecal) coliform counts in the lagoon water were 2.39* 10^4 and 9.5* 10^3 cfu/100 ml, respectively. The E. coli level was 1.93* 10^3 cfu/100 ml. These data support the hypothesis that the lagoon was the source of the outbreak among holiday-makers on the KZN Coast. The lagoon was reportedly contaminated by the wastewater treatment works effluent, which drained into the river flowing into the lagoon.

How many people were ill?

{'answer_start': [2183], 'text': ['311']}

Contamination Question Answering

An unexpected increase in gastroenteritis cases was reported by healthcare workers on the KwaZulu-Natal Coast, South Africa, January 2017 with >600 cases seen over a 3-week period. A case-control study was conducted to identify the source and risk factors associated with the outbreak so as to recommend control and prevention measures. Record review identified cases and controls and structured-telephonic interviews were conducted to obtain exposure history. Stool specimens were collected from 20 cases along with environmental samples and both screened for enteric pathogens. A reported sewage contamination event impacting the lagoon was the likely source with person-to-person spread perpetuating the outbreak. On 5 January 2017, the Outbreak Response Unit (ORU) of the National Institute for Communicable Diseases (NICD), SA, was alerted to a high number of persons falling ill with gastrointestinal symptoms (diarrhoea and/or vomiting) on the coast of KZN Province. The alert from health authorities in the KZN Province indicated that between 14 December 2016 and 5 January 2017, 690 people presented with gastrointestinal symptoms at a private hospital on the KZN south coast. Based on the available information at the time, which included local newspaper and online articles that reported a sewage spillage into a nearby lagoon; the investigating team hypothesised that contamination of a coastal lagoon could have led to the outbreak. The outbreak occurred within an urban community on the south coast of KZN Province during December 2016 and January 2017. A case-control study was conducted, with a case defined as a person of any age who presented to the private hospitals emergency department between 19 December 2016 and 6 January 2017 with an acute onset of diarrhoea and/or vomiting. Twenty acute phase stool specimens were collected from cases presenting to the hospital between 6 and 10 January 2017 and sent cooled to the Centre for Enteric Diseases (CED), NICD, for testing. Water samples were collected from the lagoon and a nearby wastewater treatment works discharge (final effluent), which drains into a river that flows into the lagoon (Fig. 1). A total of 311 cases and 126 controls were identified. The median age for the cases was 21 years (interquartile range 1040 years). The most common symptoms were vomiting (85%; 133/157), diarrhoea (73%; 115/157) and abdominal cramps (31%; 49/157). Of the 20 clinical specimens tested, 11 (55%) tested positive for NoV; nine were positive for NoV GI, while two were positive for NoV GII. Aeromonas, enterovirus and EPEC were also detected in one NoV GI-positive specimen and STEC in another NoV GI-positive specimen. Environmental samples The total coliform and thermotolerant (faecal) coliform counts in the lagoon water were 2.39* 10^4 and 9.5* 10^3 cfu/100 ml, respectively. The E. coli level was 1.93* 10^3 cfu/100 ml. These data support the hypothesis that the lagoon was the source of the outbreak among holiday-makers on the KZN Coast. The lagoon was reportedly contaminated by the wastewater treatment works effluent, which drained into the river flowing into the lagoon.

What are the pathogens?

{'answer_start': [2485], 'text': ['NoV']}

Contamination Question Answering

An unexpected increase in gastroenteritis cases was reported by healthcare workers on the KwaZulu-Natal Coast, South Africa, January 2017 with >600 cases seen over a 3-week period. A case-control study was conducted to identify the source and risk factors associated with the outbreak so as to recommend control and prevention measures. Record review identified cases and controls and structured-telephonic interviews were conducted to obtain exposure history. Stool specimens were collected from 20 cases along with environmental samples and both screened for enteric pathogens. A reported sewage contamination event impacting the lagoon was the likely source with person-to-person spread perpetuating the outbreak. On 5 January 2017, the Outbreak Response Unit (ORU) of the National Institute for Communicable Diseases (NICD), SA, was alerted to a high number of persons falling ill with gastrointestinal symptoms (diarrhoea and/or vomiting) on the coast of KZN Province. The alert from health authorities in the KZN Province indicated that between 14 December 2016 and 5 January 2017, 690 people presented with gastrointestinal symptoms at a private hospital on the KZN south coast. Based on the available information at the time, which included local newspaper and online articles that reported a sewage spillage into a nearby lagoon; the investigating team hypothesised that contamination of a coastal lagoon could have led to the outbreak. The outbreak occurred within an urban community on the south coast of KZN Province during December 2016 and January 2017. A case-control study was conducted, with a case defined as a person of any age who presented to the private hospitals emergency department between 19 December 2016 and 6 January 2017 with an acute onset of diarrhoea and/or vomiting. Twenty acute phase stool specimens were collected from cases presenting to the hospital between 6 and 10 January 2017 and sent cooled to the Centre for Enteric Diseases (CED), NICD, for testing. Water samples were collected from the lagoon and a nearby wastewater treatment works discharge (final effluent), which drains into a river that flows into the lagoon (Fig. 1). A total of 311 cases and 126 controls were identified. The median age for the cases was 21 years (interquartile range 1040 years). The most common symptoms were vomiting (85%; 133/157), diarrhoea (73%; 115/157) and abdominal cramps (31%; 49/157). Of the 20 clinical specimens tested, 11 (55%) tested positive for NoV; nine were positive for NoV GI, while two were positive for NoV GII. Aeromonas, enterovirus and EPEC were also detected in one NoV GI-positive specimen and STEC in another NoV GI-positive specimen. Environmental samples The total coliform and thermotolerant (faecal) coliform counts in the lagoon water were 2.39* 10^4 and 9.5* 10^3 cfu/100 ml, respectively. The E. coli level was 1.93* 10^3 cfu/100 ml. These data support the hypothesis that the lagoon was the source of the outbreak among holiday-makers on the KZN Coast. The lagoon was reportedly contaminated by the wastewater treatment works effluent, which drained into the river flowing into the lagoon.

What are the symptoms?

{'answer_start': [917], 'text': ['diarrhoea and/or vomiting']}

Contamination Question Answering

An unexpected increase in gastroenteritis cases was reported by healthcare workers on the KwaZulu-Natal Coast, South Africa, January 2017 with >600 cases seen over a 3-week period. A case-control study was conducted to identify the source and risk factors associated with the outbreak so as to recommend control and prevention measures. Record review identified cases and controls and structured-telephonic interviews were conducted to obtain exposure history. Stool specimens were collected from 20 cases along with environmental samples and both screened for enteric pathogens. A reported sewage contamination event impacting the lagoon was the likely source with person-to-person spread perpetuating the outbreak. On 5 January 2017, the Outbreak Response Unit (ORU) of the National Institute for Communicable Diseases (NICD), SA, was alerted to a high number of persons falling ill with gastrointestinal symptoms (diarrhoea and/or vomiting) on the coast of KZN Province. The alert from health authorities in the KZN Province indicated that between 14 December 2016 and 5 January 2017, 690 people presented with gastrointestinal symptoms at a private hospital on the KZN south coast. Based on the available information at the time, which included local newspaper and online articles that reported a sewage spillage into a nearby lagoon; the investigating team hypothesised that contamination of a coastal lagoon could have led to the outbreak. The outbreak occurred within an urban community on the south coast of KZN Province during December 2016 and January 2017. A case-control study was conducted, with a case defined as a person of any age who presented to the private hospitals emergency department between 19 December 2016 and 6 January 2017 with an acute onset of diarrhoea and/or vomiting. Twenty acute phase stool specimens were collected from cases presenting to the hospital between 6 and 10 January 2017 and sent cooled to the Centre for Enteric Diseases (CED), NICD, for testing. Water samples were collected from the lagoon and a nearby wastewater treatment works discharge (final effluent), which drains into a river that flows into the lagoon (Fig. 1). A total of 311 cases and 126 controls were identified. The median age for the cases was 21 years (interquartile range 1040 years). The most common symptoms were vomiting (85%; 133/157), diarrhoea (73%; 115/157) and abdominal cramps (31%; 49/157). Of the 20 clinical specimens tested, 11 (55%) tested positive for NoV; nine were positive for NoV GI, while two were positive for NoV GII. Aeromonas, enterovirus and EPEC were also detected in one NoV GI-positive specimen and STEC in another NoV GI-positive specimen. Environmental samples The total coliform and thermotolerant (faecal) coliform counts in the lagoon water were 2.39* 10^4 and 9.5* 10^3 cfu/100 ml, respectively. The E. coli level was 1.93* 10^3 cfu/100 ml. These data support the hypothesis that the lagoon was the source of the outbreak among holiday-makers on the KZN Coast. The lagoon was reportedly contaminated by the wastewater treatment works effluent, which drained into the river flowing into the lagoon.

What is the concentration of the pathogen?

{'answer_start': [2869], 'text': ['1.93* 10^3 cfu/100 ml']}

Contamination Question Answering

An unexpected increase in gastroenteritis cases was reported by healthcare workers on the KwaZulu-Natal Coast, South Africa, January 2017 with >600 cases seen over a 3-week period. A case-control study was conducted to identify the source and risk factors associated with the outbreak so as to recommend control and prevention measures. Record review identified cases and controls and structured-telephonic interviews were conducted to obtain exposure history. Stool specimens were collected from 20 cases along with environmental samples and both screened for enteric pathogens. A reported sewage contamination event impacting the lagoon was the likely source with person-to-person spread perpetuating the outbreak. On 5 January 2017, the Outbreak Response Unit (ORU) of the National Institute for Communicable Diseases (NICD), SA, was alerted to a high number of persons falling ill with gastrointestinal symptoms (diarrhoea and/or vomiting) on the coast of KZN Province. The alert from health authorities in the KZN Province indicated that between 14 December 2016 and 5 January 2017, 690 people presented with gastrointestinal symptoms at a private hospital on the KZN south coast. Based on the available information at the time, which included local newspaper and online articles that reported a sewage spillage into a nearby lagoon; the investigating team hypothesised that contamination of a coastal lagoon could have led to the outbreak. The outbreak occurred within an urban community on the south coast of KZN Province during December 2016 and January 2017. A case-control study was conducted, with a case defined as a person of any age who presented to the private hospitals emergency department between 19 December 2016 and 6 January 2017 with an acute onset of diarrhoea and/or vomiting. Twenty acute phase stool specimens were collected from cases presenting to the hospital between 6 and 10 January 2017 and sent cooled to the Centre for Enteric Diseases (CED), NICD, for testing. Water samples were collected from the lagoon and a nearby wastewater treatment works discharge (final effluent), which drains into a river that flows into the lagoon (Fig. 1). A total of 311 cases and 126 controls were identified. The median age for the cases was 21 years (interquartile range 1040 years). The most common symptoms were vomiting (85%; 133/157), diarrhoea (73%; 115/157) and abdominal cramps (31%; 49/157). Of the 20 clinical specimens tested, 11 (55%) tested positive for NoV; nine were positive for NoV GI, while two were positive for NoV GII. Aeromonas, enterovirus and EPEC were also detected in one NoV GI-positive specimen and STEC in another NoV GI-positive specimen. Environmental samples The total coliform and thermotolerant (faecal) coliform counts in the lagoon water were 2.39* 10^4 and 9.5* 10^3 cfu/100 ml, respectively. The E. coli level was 1.93* 10^3 cfu/100 ml. These data support the hypothesis that the lagoon was the source of the outbreak among holiday-makers on the KZN Coast. The lagoon was reportedly contaminated by the wastewater treatment works effluent, which drained into the river flowing into the lagoon.

What is the event?

{'answer_start': [26], 'text': ['gastroenteritis cases']}

Contamination Question Answering

An unexpected increase in gastroenteritis cases was reported by healthcare workers on the KwaZulu-Natal Coast, South Africa, January 2017 with >600 cases seen over a 3-week period. A case-control study was conducted to identify the source and risk factors associated with the outbreak so as to recommend control and prevention measures. Record review identified cases and controls and structured-telephonic interviews were conducted to obtain exposure history. Stool specimens were collected from 20 cases along with environmental samples and both screened for enteric pathogens. A reported sewage contamination event impacting the lagoon was the likely source with person-to-person spread perpetuating the outbreak. On 5 January 2017, the Outbreak Response Unit (ORU) of the National Institute for Communicable Diseases (NICD), SA, was alerted to a high number of persons falling ill with gastrointestinal symptoms (diarrhoea and/or vomiting) on the coast of KZN Province. The alert from health authorities in the KZN Province indicated that between 14 December 2016 and 5 January 2017, 690 people presented with gastrointestinal symptoms at a private hospital on the KZN south coast. Based on the available information at the time, which included local newspaper and online articles that reported a sewage spillage into a nearby lagoon; the investigating team hypothesised that contamination of a coastal lagoon could have led to the outbreak. The outbreak occurred within an urban community on the south coast of KZN Province during December 2016 and January 2017. A case-control study was conducted, with a case defined as a person of any age who presented to the private hospitals emergency department between 19 December 2016 and 6 January 2017 with an acute onset of diarrhoea and/or vomiting. Twenty acute phase stool specimens were collected from cases presenting to the hospital between 6 and 10 January 2017 and sent cooled to the Centre for Enteric Diseases (CED), NICD, for testing. Water samples were collected from the lagoon and a nearby wastewater treatment works discharge (final effluent), which drains into a river that flows into the lagoon (Fig. 1). A total of 311 cases and 126 controls were identified. The median age for the cases was 21 years (interquartile range 1040 years). The most common symptoms were vomiting (85%; 133/157), diarrhoea (73%; 115/157) and abdominal cramps (31%; 49/157). Of the 20 clinical specimens tested, 11 (55%) tested positive for NoV; nine were positive for NoV GI, while two were positive for NoV GII. Aeromonas, enterovirus and EPEC were also detected in one NoV GI-positive specimen and STEC in another NoV GI-positive specimen. Environmental samples The total coliform and thermotolerant (faecal) coliform counts in the lagoon water were 2.39* 10^4 and 9.5* 10^3 cfu/100 ml, respectively. The E. coli level was 1.93* 10^3 cfu/100 ml. These data support the hypothesis that the lagoon was the source of the outbreak among holiday-makers on the KZN Coast. The lagoon was reportedly contaminated by the wastewater treatment works effluent, which drained into the river flowing into the lagoon.

What are the initial steps of investigation?

{'answer_start': [183], 'text': ['case-control study']}

Contamination Question Answering

An unexpected increase in gastroenteritis cases was reported by healthcare workers on the KwaZulu-Natal Coast, South Africa, January 2017 with >600 cases seen over a 3-week period. A case-control study was conducted to identify the source and risk factors associated with the outbreak so as to recommend control and prevention measures. Record review identified cases and controls and structured-telephonic interviews were conducted to obtain exposure history. Stool specimens were collected from 20 cases along with environmental samples and both screened for enteric pathogens. A reported sewage contamination event impacting the lagoon was the likely source with person-to-person spread perpetuating the outbreak. On 5 January 2017, the Outbreak Response Unit (ORU) of the National Institute for Communicable Diseases (NICD), SA, was alerted to a high number of persons falling ill with gastrointestinal symptoms (diarrhoea and/or vomiting) on the coast of KZN Province. The alert from health authorities in the KZN Province indicated that between 14 December 2016 and 5 January 2017, 690 people presented with gastrointestinal symptoms at a private hospital on the KZN south coast. Based on the available information at the time, which included local newspaper and online articles that reported a sewage spillage into a nearby lagoon; the investigating team hypothesised that contamination of a coastal lagoon could have led to the outbreak. The outbreak occurred within an urban community on the south coast of KZN Province during December 2016 and January 2017. A case-control study was conducted, with a case defined as a person of any age who presented to the private hospitals emergency department between 19 December 2016 and 6 January 2017 with an acute onset of diarrhoea and/or vomiting. Twenty acute phase stool specimens were collected from cases presenting to the hospital between 6 and 10 January 2017 and sent cooled to the Centre for Enteric Diseases (CED), NICD, for testing. Water samples were collected from the lagoon and a nearby wastewater treatment works discharge (final effluent), which drains into a river that flows into the lagoon (Fig. 1). A total of 311 cases and 126 controls were identified. The median age for the cases was 21 years (interquartile range 1040 years). The most common symptoms were vomiting (85%; 133/157), diarrhoea (73%; 115/157) and abdominal cramps (31%; 49/157). Of the 20 clinical specimens tested, 11 (55%) tested positive for NoV; nine were positive for NoV GI, while two were positive for NoV GII. Aeromonas, enterovirus and EPEC were also detected in one NoV GI-positive specimen and STEC in another NoV GI-positive specimen. Environmental samples The total coliform and thermotolerant (faecal) coliform counts in the lagoon water were 2.39* 10^4 and 9.5* 10^3 cfu/100 ml, respectively. The E. coli level was 1.93* 10^3 cfu/100 ml. These data support the hypothesis that the lagoon was the source of the outbreak among holiday-makers on the KZN Coast. The lagoon was reportedly contaminated by the wastewater treatment works effluent, which drained into the river flowing into the lagoon.

What is the duration of the event?

{'answer_start': [1043], 'text': ['between 14 December 2016 and 5 January 2017']}

Contamination Question Answering

An unexpected increase in gastroenteritis cases was reported by healthcare workers on the KwaZulu-Natal Coast, South Africa, January 2017 with >600 cases seen over a 3-week period. A case-control study was conducted to identify the source and risk factors associated with the outbreak so as to recommend control and prevention measures. Record review identified cases and controls and structured-telephonic interviews were conducted to obtain exposure history. Stool specimens were collected from 20 cases along with environmental samples and both screened for enteric pathogens. A reported sewage contamination event impacting the lagoon was the likely source with person-to-person spread perpetuating the outbreak. On 5 January 2017, the Outbreak Response Unit (ORU) of the National Institute for Communicable Diseases (NICD), SA, was alerted to a high number of persons falling ill with gastrointestinal symptoms (diarrhoea and/or vomiting) on the coast of KZN Province. The alert from health authorities in the KZN Province indicated that between 14 December 2016 and 5 January 2017, 690 people presented with gastrointestinal symptoms at a private hospital on the KZN south coast. Based on the available information at the time, which included local newspaper and online articles that reported a sewage spillage into a nearby lagoon; the investigating team hypothesised that contamination of a coastal lagoon could have led to the outbreak. The outbreak occurred within an urban community on the south coast of KZN Province during December 2016 and January 2017. A case-control study was conducted, with a case defined as a person of any age who presented to the private hospitals emergency department between 19 December 2016 and 6 January 2017 with an acute onset of diarrhoea and/or vomiting. Twenty acute phase stool specimens were collected from cases presenting to the hospital between 6 and 10 January 2017 and sent cooled to the Centre for Enteric Diseases (CED), NICD, for testing. Water samples were collected from the lagoon and a nearby wastewater treatment works discharge (final effluent), which drains into a river that flows into the lagoon (Fig. 1). A total of 311 cases and 126 controls were identified. The median age for the cases was 21 years (interquartile range 1040 years). The most common symptoms were vomiting (85%; 133/157), diarrhoea (73%; 115/157) and abdominal cramps (31%; 49/157). Of the 20 clinical specimens tested, 11 (55%) tested positive for NoV; nine were positive for NoV GI, while two were positive for NoV GII. Aeromonas, enterovirus and EPEC were also detected in one NoV GI-positive specimen and STEC in another NoV GI-positive specimen. Environmental samples The total coliform and thermotolerant (faecal) coliform counts in the lagoon water were 2.39* 10^4 and 9.5* 10^3 cfu/100 ml, respectively. The E. coli level was 1.93* 10^3 cfu/100 ml. These data support the hypothesis that the lagoon was the source of the outbreak among holiday-makers on the KZN Coast. The lagoon was reportedly contaminated by the wastewater treatment works effluent, which drained into the river flowing into the lagoon.

From when until when the event happened

{'answer_start': [1529], 'text': ['during December 2016 and January 2017']}

Contamination Question Answering

An unexpected increase in gastroenteritis cases was reported by healthcare workers on the KwaZulu-Natal Coast, South Africa, January 2017 with >600 cases seen over a 3-week period. A case-control study was conducted to identify the source and risk factors associated with the outbreak so as to recommend control and prevention measures. Record review identified cases and controls and structured-telephonic interviews were conducted to obtain exposure history. Stool specimens were collected from 20 cases along with environmental samples and both screened for enteric pathogens. A reported sewage contamination event impacting the lagoon was the likely source with person-to-person spread perpetuating the outbreak. On 5 January 2017, the Outbreak Response Unit (ORU) of the National Institute for Communicable Diseases (NICD), SA, was alerted to a high number of persons falling ill with gastrointestinal symptoms (diarrhoea and/or vomiting) on the coast of KZN Province. The alert from health authorities in the KZN Province indicated that between 14 December 2016 and 5 January 2017, 690 people presented with gastrointestinal symptoms at a private hospital on the KZN south coast. Based on the available information at the time, which included local newspaper and online articles that reported a sewage spillage into a nearby lagoon; the investigating team hypothesised that contamination of a coastal lagoon could have led to the outbreak. The outbreak occurred within an urban community on the south coast of KZN Province during December 2016 and January 2017. A case-control study was conducted, with a case defined as a person of any age who presented to the private hospitals emergency department between 19 December 2016 and 6 January 2017 with an acute onset of diarrhoea and/or vomiting. Twenty acute phase stool specimens were collected from cases presenting to the hospital between 6 and 10 January 2017 and sent cooled to the Centre for Enteric Diseases (CED), NICD, for testing. Water samples were collected from the lagoon and a nearby wastewater treatment works discharge (final effluent), which drains into a river that flows into the lagoon (Fig. 1). A total of 311 cases and 126 controls were identified. The median age for the cases was 21 years (interquartile range 1040 years). The most common symptoms were vomiting (85%; 133/157), diarrhoea (73%; 115/157) and abdominal cramps (31%; 49/157). Of the 20 clinical specimens tested, 11 (55%) tested positive for NoV; nine were positive for NoV GI, while two were positive for NoV GII. Aeromonas, enterovirus and EPEC were also detected in one NoV GI-positive specimen and STEC in another NoV GI-positive specimen. Environmental samples The total coliform and thermotolerant (faecal) coliform counts in the lagoon water were 2.39* 10^4 and 9.5* 10^3 cfu/100 ml, respectively. The E. coli level was 1.93* 10^3 cfu/100 ml. These data support the hypothesis that the lagoon was the source of the outbreak among holiday-makers on the KZN Coast. The lagoon was reportedly contaminated by the wastewater treatment works effluent, which drained into the river flowing into the lagoon.

What type of samples were examined?

{'answer_start': [1996], 'text': ['Water samples']}

Contamination Question Answering

An unexpected increase in gastroenteritis cases was reported by healthcare workers on the KwaZulu-Natal Coast, South Africa, January 2017 with >600 cases seen over a 3-week period. A case-control study was conducted to identify the source and risk factors associated with the outbreak so as to recommend control and prevention measures. Record review identified cases and controls and structured-telephonic interviews were conducted to obtain exposure history. Stool specimens were collected from 20 cases along with environmental samples and both screened for enteric pathogens. A reported sewage contamination event impacting the lagoon was the likely source with person-to-person spread perpetuating the outbreak. On 5 January 2017, the Outbreak Response Unit (ORU) of the National Institute for Communicable Diseases (NICD), SA, was alerted to a high number of persons falling ill with gastrointestinal symptoms (diarrhoea and/or vomiting) on the coast of KZN Province. The alert from health authorities in the KZN Province indicated that between 14 December 2016 and 5 January 2017, 690 people presented with gastrointestinal symptoms at a private hospital on the KZN south coast. Based on the available information at the time, which included local newspaper and online articles that reported a sewage spillage into a nearby lagoon; the investigating team hypothesised that contamination of a coastal lagoon could have led to the outbreak. The outbreak occurred within an urban community on the south coast of KZN Province during December 2016 and January 2017. A case-control study was conducted, with a case defined as a person of any age who presented to the private hospitals emergency department between 19 December 2016 and 6 January 2017 with an acute onset of diarrhoea and/or vomiting. Twenty acute phase stool specimens were collected from cases presenting to the hospital between 6 and 10 January 2017 and sent cooled to the Centre for Enteric Diseases (CED), NICD, for testing. Water samples were collected from the lagoon and a nearby wastewater treatment works discharge (final effluent), which drains into a river that flows into the lagoon (Fig. 1). A total of 311 cases and 126 controls were identified. The median age for the cases was 21 years (interquartile range 1040 years). The most common symptoms were vomiting (85%; 133/157), diarrhoea (73%; 115/157) and abdominal cramps (31%; 49/157). Of the 20 clinical specimens tested, 11 (55%) tested positive for NoV; nine were positive for NoV GI, while two were positive for NoV GII. Aeromonas, enterovirus and EPEC were also detected in one NoV GI-positive specimen and STEC in another NoV GI-positive specimen. Environmental samples The total coliform and thermotolerant (faecal) coliform counts in the lagoon water were 2.39* 10^4 and 9.5* 10^3 cfu/100 ml, respectively. The E. coli level was 1.93* 10^3 cfu/100 ml. These data support the hypothesis that the lagoon was the source of the outbreak among holiday-makers on the KZN Coast. The lagoon was reportedly contaminated by the wastewater treatment works effluent, which drained into the river flowing into the lagoon.

What was the age of the affected people?

{'answer_start': [2260], 'text': ['21 years']}

Contamination Question Answering

An unexpected increase in gastroenteritis cases was reported by healthcare workers on the KwaZulu-Natal Coast, South Africa, January 2017 with >600 cases seen over a 3-week period. A case-control study was conducted to identify the source and risk factors associated with the outbreak so as to recommend control and prevention measures. Record review identified cases and controls and structured-telephonic interviews were conducted to obtain exposure history. Stool specimens were collected from 20 cases along with environmental samples and both screened for enteric pathogens. A reported sewage contamination event impacting the lagoon was the likely source with person-to-person spread perpetuating the outbreak. On 5 January 2017, the Outbreak Response Unit (ORU) of the National Institute for Communicable Diseases (NICD), SA, was alerted to a high number of persons falling ill with gastrointestinal symptoms (diarrhoea and/or vomiting) on the coast of KZN Province. The alert from health authorities in the KZN Province indicated that between 14 December 2016 and 5 January 2017, 690 people presented with gastrointestinal symptoms at a private hospital on the KZN south coast. Based on the available information at the time, which included local newspaper and online articles that reported a sewage spillage into a nearby lagoon; the investigating team hypothesised that contamination of a coastal lagoon could have led to the outbreak. The outbreak occurred within an urban community on the south coast of KZN Province during December 2016 and January 2017. A case-control study was conducted, with a case defined as a person of any age who presented to the private hospitals emergency department between 19 December 2016 and 6 January 2017 with an acute onset of diarrhoea and/or vomiting. Twenty acute phase stool specimens were collected from cases presenting to the hospital between 6 and 10 January 2017 and sent cooled to the Centre for Enteric Diseases (CED), NICD, for testing. Water samples were collected from the lagoon and a nearby wastewater treatment works discharge (final effluent), which drains into a river that flows into the lagoon (Fig. 1). A total of 311 cases and 126 controls were identified. The median age for the cases was 21 years (interquartile range 1040 years). The most common symptoms were vomiting (85%; 133/157), diarrhoea (73%; 115/157) and abdominal cramps (31%; 49/157). Of the 20 clinical specimens tested, 11 (55%) tested positive for NoV; nine were positive for NoV GI, while two were positive for NoV GII. Aeromonas, enterovirus and EPEC were also detected in one NoV GI-positive specimen and STEC in another NoV GI-positive specimen. Environmental samples The total coliform and thermotolerant (faecal) coliform counts in the lagoon water were 2.39* 10^4 and 9.5* 10^3 cfu/100 ml, respectively. The E. coli level was 1.93* 10^3 cfu/100 ml. These data support the hypothesis that the lagoon was the source of the outbreak among holiday-makers on the KZN Coast. The lagoon was reportedly contaminated by the wastewater treatment works effluent, which drained into the river flowing into the lagoon.

What is the source of contamination?

{'answer_start': [632], 'text': ['lagoon']}

Contamination Question Answering

An unexpected increase in gastroenteritis cases was reported by healthcare workers on the KwaZulu-Natal Coast, South Africa, January 2017 with >600 cases seen over a 3-week period. A case-control study was conducted to identify the source and risk factors associated with the outbreak so as to recommend control and prevention measures. Record review identified cases and controls and structured-telephonic interviews were conducted to obtain exposure history. Stool specimens were collected from 20 cases along with environmental samples and both screened for enteric pathogens. A reported sewage contamination event impacting the lagoon was the likely source with person-to-person spread perpetuating the outbreak. On 5 January 2017, the Outbreak Response Unit (ORU) of the National Institute for Communicable Diseases (NICD), SA, was alerted to a high number of persons falling ill with gastrointestinal symptoms (diarrhoea and/or vomiting) on the coast of KZN Province. The alert from health authorities in the KZN Province indicated that between 14 December 2016 and 5 January 2017, 690 people presented with gastrointestinal symptoms at a private hospital on the KZN south coast. Based on the available information at the time, which included local newspaper and online articles that reported a sewage spillage into a nearby lagoon; the investigating team hypothesised that contamination of a coastal lagoon could have led to the outbreak. The outbreak occurred within an urban community on the south coast of KZN Province during December 2016 and January 2017. A case-control study was conducted, with a case defined as a person of any age who presented to the private hospitals emergency department between 19 December 2016 and 6 January 2017 with an acute onset of diarrhoea and/or vomiting. Twenty acute phase stool specimens were collected from cases presenting to the hospital between 6 and 10 January 2017 and sent cooled to the Centre for Enteric Diseases (CED), NICD, for testing. Water samples were collected from the lagoon and a nearby wastewater treatment works discharge (final effluent), which drains into a river that flows into the lagoon (Fig. 1). A total of 311 cases and 126 controls were identified. The median age for the cases was 21 years (interquartile range 1040 years). The most common symptoms were vomiting (85%; 133/157), diarrhoea (73%; 115/157) and abdominal cramps (31%; 49/157). Of the 20 clinical specimens tested, 11 (55%) tested positive for NoV; nine were positive for NoV GI, while two were positive for NoV GII. Aeromonas, enterovirus and EPEC were also detected in one NoV GI-positive specimen and STEC in another NoV GI-positive specimen. Environmental samples The total coliform and thermotolerant (faecal) coliform counts in the lagoon water were 2.39* 10^4 and 9.5* 10^3 cfu/100 ml, respectively. The E. coli level was 1.93* 10^3 cfu/100 ml. These data support the hypothesis that the lagoon was the source of the outbreak among holiday-makers on the KZN Coast. The lagoon was reportedly contaminated by the wastewater treatment works effluent, which drained into the river flowing into the lagoon.

What was the alert of the event?

{'answer_start': [863], 'text': ['persons falling ill with gastrointestinal symptoms']}

Contamination Question Answering

An unexpected increase in gastroenteritis cases was reported by healthcare workers on the KwaZulu-Natal Coast, South Africa, January 2017 with >600 cases seen over a 3-week period. A case-control study was conducted to identify the source and risk factors associated with the outbreak so as to recommend control and prevention measures. Record review identified cases and controls and structured-telephonic interviews were conducted to obtain exposure history. Stool specimens were collected from 20 cases along with environmental samples and both screened for enteric pathogens. A reported sewage contamination event impacting the lagoon was the likely source with person-to-person spread perpetuating the outbreak. On 5 January 2017, the Outbreak Response Unit (ORU) of the National Institute for Communicable Diseases (NICD), SA, was alerted to a high number of persons falling ill with gastrointestinal symptoms (diarrhoea and/or vomiting) on the coast of KZN Province. The alert from health authorities in the KZN Province indicated that between 14 December 2016 and 5 January 2017, 690 people presented with gastrointestinal symptoms at a private hospital on the KZN south coast. Based on the available information at the time, which included local newspaper and online articles that reported a sewage spillage into a nearby lagoon; the investigating team hypothesised that contamination of a coastal lagoon could have led to the outbreak. The outbreak occurred within an urban community on the south coast of KZN Province during December 2016 and January 2017. A case-control study was conducted, with a case defined as a person of any age who presented to the private hospitals emergency department between 19 December 2016 and 6 January 2017 with an acute onset of diarrhoea and/or vomiting. Twenty acute phase stool specimens were collected from cases presenting to the hospital between 6 and 10 January 2017 and sent cooled to the Centre for Enteric Diseases (CED), NICD, for testing. Water samples were collected from the lagoon and a nearby wastewater treatment works discharge (final effluent), which drains into a river that flows into the lagoon (Fig. 1). A total of 311 cases and 126 controls were identified. The median age for the cases was 21 years (interquartile range 1040 years). The most common symptoms were vomiting (85%; 133/157), diarrhoea (73%; 115/157) and abdominal cramps (31%; 49/157). Of the 20 clinical specimens tested, 11 (55%) tested positive for NoV; nine were positive for NoV GI, while two were positive for NoV GII. Aeromonas, enterovirus and EPEC were also detected in one NoV GI-positive specimen and STEC in another NoV GI-positive specimen. Environmental samples The total coliform and thermotolerant (faecal) coliform counts in the lagoon water were 2.39* 10^4 and 9.5* 10^3 cfu/100 ml, respectively. The E. coli level was 1.93* 10^3 cfu/100 ml. These data support the hypothesis that the lagoon was the source of the outbreak among holiday-makers on the KZN Coast. The lagoon was reportedly contaminated by the wastewater treatment works effluent, which drained into the river flowing into the lagoon.

What were the associated pathogens of concern?

{'answer_start': [2616], 'text': ['NoV GI']}

Contamination Question Answering

In May 2007, Escherichia coli was detected in tap water supplied by a company in North Holland. The company issued advice through mass media to boil tap water before consumption; this advice was lifted six days later. A cross-sectional study was implemented to investigate compliance among residents in this area. Based on postcode, a total of 300 households, chosen randomly from a database of a private company performing internet-based surveys for different marketing purposes, were sent a self-administered questionnaire for this study. The questionnaire contained questions on demographic information, source of information regarding the advice, response to it and personal opinions on the companys reaction and the advice. Ninety-nine (66%) households of the affected area and 90 (60%) households from non-affected areas served by the same company replied to the survey. All respondents knew about the advice. 81.8% of the respondents in the affected area and 5.6% of the non-affected areas reported complying with the advisory. Most respondents from the affected area still used unboiled water to brush teeth, wash salads and fruits. There was no difference in compliance between men and women. Using the mass media was proved to be efficient to inform the public and could be used in the future in similar settings. However, more detailed wording of boiling advices should be considered in the future. Introduction Consumption of drinking water may cause waterborne disease which can be prevented by protection of the source water, efficient treatment processes and reliable distribution systems. The European Union Drinking Water Directive [1] demands monitoring of tap water for different parameters, such as Escherichia coli, to indicate possible faecal contamination from humans and animals. System failure or human error may cause an increase in the level of pathogens in the water posing a risk of waterborne disease. For example, in 2001, a large outbreak of gastroenteritis occurred due to accidental introduction of partially treated water to the drinking water supply system in the Netherlands, resulting in 921 households being exposed to contaminated water [2]. In the event that faecal contamination is detected the drinking water company may issue an advice to boil tap water before using it for domestic purposes. On 15 May 2007, E. coli was detected in samples collected the day before of the finished tap water delivered by a company in the province Noord-Holland (North-Holland) in the Netherlands. For preventive reasons, on the same day the company issued an advice for consumers to boil tap water for two minutes before consumption but that this was not necessary for taking a shower or washing. This information was broadcasted through mass-media including the national and regional television channel, radio and newspapers. In addition, a public website used during emergency situations (www.crisis.nl) and a toll-free telephone number were made available for the public to provide information to households in the affected area. The boil water advice had an impact on approximately 180,000 households in the affected area comprising 13 municipalities. The advice was lifted a week later, on 22 May 2007, as risk for public health was no longer present. In September 2007, the water company published a press release informing that the cause of the water contamination was due to run-off of rainwater contaminated with faeces of breeding gulls on the roof that had seeped into one of the six storage rooms [3]. Elevated levels of microorganisms in drinking water may represent a public health risk. For this reason, we investigated compliance with boil water advice issued by the private water company following the 2007 incident. Methods A cross-sectional study was implemented to investigate factors that may have affected water consumption habits of the residents in the area supplied by the water company. For this purpose, on the companys behalf, a self-administered questionnaire was sent to 300 households in June 2007. Households were selected on the basis of their residence postcodes; half in the area where the advice was valid and half in areas served by the same company but where the advice did not apply. These participants were derived from a database of a private company that conducts online consumer surveys for marketing purposes. The questionnaire contained questions on demographic information, level of urbanisation, source and time of receiving the information regarding the advice, initial and secondary response to the advice and personal opinions on the companys response and the advice itself. The data were sent back to the drinking water company and the National Institute for Public Health and the Environment, where they were analysed. The statistical analysis was done with STATA v10. 2 EUROSURVEILLANCE Vol. 14 Issue 12 26 March 2009 www.eurosurveillance.org Results Ninety-nine households (66%) from the area affected by water contamination and 90 households (60%) from control areas supplied with water by the same company replied to the survey. Women more often than men responded to the questionnaire in both the affected and the non-affected areas (57.7% of all responders). The respondents represented 189 households with a total population of 505 people, 176 (34.9%) of whom were below the age of 18 years. There was no statistically significant difference in the number of children per household between the affected and the non-affected areas (p=0.112). Descriptive results for the two different areas are presented in Table 1. All 189 respondents (100%) in both areas answered that they had been informed about the advice. Ninety-five (50.3%) of them said they had first heard about it through the television. Other sources were radio (24.3%), friends, relatives or neighbours (22.8%), newspapers (19.6%) and the internet (7.4%). Persons living in the affected area were more frequently disappointed (14.1%) about the choice of the company to use mass media for the advice than people residing in the non- affected area (2.2%). In the affected area, seven (9.3%) of the respondents had first reacted with fear to the information on the possible contamination of water, 34 (45.3%) responded with self- control and 34 (45.3%) with the intention to take measures. The corresponding percentages for the non affected area were 15.7%, 72.9% and 11.4%. About half (48.5%) of the respondents from the affected area said they had looked for more information when they had heard about the advice, while the corresponding proportion of respondents from the non-affected area was only 8.9% (p<0.001). The most common source of active search for more information was the website of the water supply company. Eighty-one (81.8%) of all respondents in the affected area said they had complied with the advice. This was done by buying bottled water (43.4% of all respondents in affected area) or boiling tap water for two minutes before consuming it (70.7%). None of the respondents in the area stopped consuming tap water completely. Five (5.6%) of the respondents in the non-affected area were buying bottled water and three of them (3.3%) were boiling tap water during the advice. These numbers were considerably lower than the corresponding ones in the affected area, but showed that compliance exceeded beyond the affected area. Even though it had not been advised to boil water for activities such as washing and showering, 26 (26.3%) of the respondents in the affected area stated that they had not been aware of that. Concerning the image of the drinking water company, 177 respondents (93.7%) thought that the company had done well informing the consumers about the water contamination and its response to it. This prevailing opinion was not different between respondents from the affected area and those from the non affected area. The respondents compliance with the advice was independent of sex, age and the presence of children in the household. However, the respondents were 138.6 times more likely to follow the advice if a second person in the household was following it as well (p<0.001). Reasons for non-compliance with the advice are given in Table 2. Some of the respondents replied that they had been using boiled water for uses other than drinking, too. These results are shown in Table 3. The majority of the respondents stated that their image of the company had not changed after the incident and the six-day advice (78.8% in the affected area and 88.9% in the non-affected area). Factors affecting compliance The type of mass media from which people in the affected area found out about the advice played no significant role in the subsequent compliance of the respondents. The highest compliance rates occurred among those in the affected area who heard about the advice from the internet (90%) or from friends (89.5%). Respondents informed by more than one source were more likely T a b l e 1 Survey on boil water advice in the North Holland province in the Netherlands, 2007, demographic characteristics of the respondents Affected area (n=99) Non-affected area (n=90) Total (n=189) p-value Respondents age (years) 47.7 48.4 48.0 0.7549 Number of people living in the household 2.62 2.82 2.72 0.2526 Number of children living in the household 0.78 1.11 0.93 0.0510 T a b l e 2 Reasons for non-compliance with boil water advice in the affected area in the North Holland province, the Netherlands, 2007 (n=11) Reason given N % I have enough immunity 1 9.1 The risk was small 1 9.1 I was not worried 3 27.3 It was too much inconvenience 2 18.2 I forgot about it 2 18.2 I had only just found out 2 18.2 Total 11 100.0 T a b l e 3 Use of boiled water for uses other than drinking in the affected area in the North Holland province, the Netherlands, 2007 (n=99) Domestic use N % To brush teeth 30 28.1 To wash salads 48 35.6 To wash fruits 51 48.4 To make coffee 56 54.7 To make ice cubes 89 87.2 To give to pets 73 69.4 EUROSURVEILLANCE Vol. 14 Issue 12 26 March 2009 www.eurosurveillance.org 3 to have complied with the advice (90.9% against 79.2%) but this difference was not statistically significant. The source of information did not depend on the age (p=0.6532). Compliance with the advice did not differ between households with children and those without children (p=0.536). Respondents who undertook active search for more information may have been more likely to follow the advice than those who did not proceed to further active search for more information (89.4% vs. 74.5%, p=0.058). Since all respondents knew about the advice, it was not possible to estimate unwitting compliance rates.

What is the initial cause of the event?

{'answer_start': [3461], 'text': ['run-off of rainwater contaminated']}