bluuebunny/crossref_metadata_2025_split huggingface dataset:
Risk factors for hepatitis C virus infection. A case-control study of blood donors in the Trent Region (UK)
Authors: Neal K. R. , Jones D. A. , Killey D. , James V. 
Published: May 2009

SUMMARYThe introduction of screening for hepatitis C virus (HCV) by the National Blood Transfusion Service identified donors who had acquired HCV infection. We undertook a case-control study amongst blood donors in the Trent Region to determine risks for HCV infection. A total of 74 blood donors confirmed positive for hepatitis C infection and 150 age, sex and donor venue matched controls were included in the study. Fifty-three percent of hepatitis C infected blood donors reported previous use of injected drugs compared to no controls; relative risk (RR) not estimatable (lower limit 95% CI = 20). Other risk factors were a history of: receipt of a blood transfusion or blood products RR = 3·6 (95% CI 1·5–8·3), having been a ‘health care worker’ RR = 2·8 (95% CI 1·1–7·6), tattooing RR = 3·3 (95% CI 1·2–8·7), and an association with having been born abroad RR = 3·2 (95% CI 1·1–9·5). No risk was shown for a history of multiple sexual partners, ear piercing or acupuncture. Injecting drug use explains more than 50% of hepatitis C infections in blood donors, a group who are less likely to have injected drugs than the general population.
Identification of outbreak-associated and other strains ofClostridium difficileby numerical analysis of SDS-PAGE protein patterns
Authors: Costas M. , Holmes B. , Ganner M. , On S. L. W. , Hoffman P. N. , Worsley M. A. , Panigrahi H. 
Published: May 2009

SUMMARYSeventy-three cultures ofClostridium difficileisolated both during, and in the period immediately following, an outbreak of infection in a group of three hospitals, were characterized by one-dimensional sodium dodecyl sulphate–polyacrylamide gel electrophoresis (SDS–PAGE) of whole-cell proteins. Each protein pattern was characterized by the presence of one or two dense bands which were highly reproducible. The protein patterns were used as the basis for a numerical analysis which divided the strains into five phenons (electrophoretic or EP types). The majority, 60 of the 73 cultures, belonged to a single phenon which included strains from both patients and the environment. We conclude that high-resolution SDS–PAGE of proteins provides an effective method for typingC. difficileand therefore for tracing the possible spread of epidemic strains in hospitals and other institutions, thereby allowing a better understanding of the epidemiology of the organism.
The frequency of culturing stools from adults with diarrhoea in Great Britain
Authors: Feldman R. A. , Banatvala N. 
Published: May 2009

SUMMARYUtilizing the Office of Population Censuses and Surveys (OPCS) Omnibus Survey, it was possible to measure the frequency with which a stool culture was obtained following episodes of diarrhoea in adults. Interviewing over 8000 adults, over a 4-month period between October 1992 and January 1993, 633 persons (7·9%) reported one episode of diarrhoea in the previous month, and 5·4 % of these individuals with diarrhoea reported that a stool had been requested for examination. No significant regional differences were observed with the sample size available. The estimate of the rate of diarrhoea in adults was just under one episode per person per year.
Prevalence of hepatitis A virus infection among sewage workers in Singapore
Authors: Heng B. H. , Goh K. T. , Doraisingham S. , Quek G. H. 
Published: May 2009

SUMMARYTo determine whether or not occupational exposure to sewage is associated with a higher seroprevalence of hepatitis A virus (HAV) infection, 600 sewage workers in Singapore were tested for total (IgG and IgM) antibody to HAV by enzyme immunoassay. Using logistic regression with stepwise procedure, the adjusted seroprevalence of sewage workers was 2·2 times higher than that of another non-occupationally exposed population group. Seroprevalence was significantly correlated with age and educational levels, the association being independent of the occupational association. The epidemiological data in the study show that sewage workers have an increased occupational risk of acquiring HAV infection and should be protected by active immunization.
Identification of astrovirus serotypes from children treated at the Hospitals for Sick Children, London 1981–93
Authors: Noel J. , Cubitt D. 
Published: May 2009

SUMMARYAn enzyme immunoassay (EIA) for astrovirus type 1 together with immune electronmicroscopy (IBM) was used to type a collection of 162 astroviruses obtained from 1981–93 from children with diarrhoea. The EIA was found to be specific for astrovirus type 1. Astrovirus types 2–4 were typed by IEM.Astrovirus type 1 was the prevalent serotype 107/125 (86%), followed by type 3 (8%), type 4 (6%) and type 2 (1 %). Six samples containing astrovirus could not be typed or detected by EIA because they were coated with coproantibodies; 11 others were not identified. Virus particles could no longer be detected in 15/162 (9%) samples following storage for≥2 years.Selected samples containing astrovirus types 1–4 were passaged in CaCO2cells and their identity confirmed by one or both assays. One sample was shown to have remained viable for 10 years when stored as an aqueous suspension at −20 °C.Two patients with severe combined immune deficiency disease (SCID) were shown to be excreting astrovirus type 1 for 32 and 102 days respectively. One child was simultaneously shedding rotavirus and the other child was excreting adenovirus.
Rubella seroepidemiology in a non-immunized population of São Paulo State, Brazil
Authors: De Azevedo Neto R. S. , Silveira A. S. B. , Nokes D. J. , Yang H. M. , Passos S. D. , Cardoso M. R. A. , Massad E. 
Published: May 2009

SUMMARYA rubella serological survey of 476 individuals selected by cluster sampling technique from Caieiras, a small town located in the outskirts of São Paulo city, southeastern Brazil, was carried out over the period November 1990–January 1991. The aim of the study was to characterize rubella epidemiology in a representative non-immunized community in south east Brazil. The survey comprised a seroprevalence study, stratified by age (0–40 years) and a seroconversion study of rubella vaccine in non-infected children below 2 years of age. Mathematical techniques were applied to resultant data sets to determine the age dependent rates of decay in the proportion of individuals with maternally derived antibodies, vaccine seroconversion, and infection of susceptibles, termed the force of infection, and to estimate the average age at first infection.
Pseudomonas pseudomalleiisolates collected over 25 years from a non-tropical endemic focus show clonality on the basis of ribotyping
Authors: Currie B. , Smith-Vaughan H. , Golledge C. , Buller N. , Sriprakash K. S. , Kemp D. J. 
Published: May 2009

SUMMARYBetween 1966 and 1991, melioidosis, a disease caused byPseudomonas pseudomalleithat is mostly confined to tropical regions, occurred in farm animals and a farmer in temperate south-west Western Australia. Using anEscherichia coliprobe containing a ribosomal RNA operon,P. pseudomalleiDNA from isolates from 8 animals, a soil sample and the human case showed an identical ribotype on Southern blotting. The ribotype was different from the 3 commonest ribotypes seen in tropical Australia. This molecular typing supports the theory of clonal introduction ofP. pseudomalleiinto a non-endemic region, with environmental contamination, local dissemination and persistence over 25 years. As melioidosis is often fatal in humans, such persistence in a temperate region is cause for concern.
The production of Clostridium botulinum type A, B and D toxin in rotting carcasses
Authors: Ortiz N. E. , Smith G. R. 
Published: May 2009

SUMMARYCarrion is a major source of botulinal toxin for animals. A type D strain of Clostridium botulinum differed from type A and B strains in producing (1) much higher concentrations of toxin in putrefying mouse carcasses at several different temperatures over a period of 35 days, (2) toxicity that sometimes persisted in mouse carcasses for at least a year, and (3) mouse carcasses with exceptionally high oral toxicity. Fish carcasses were much less favourable than mouse carcasses for type D toxigenesis.The study, together with earlier studies on types C and E, indicated that carrion contaminated with C. botulinum type C or D is likely to be particularly dangerous for animals that may ingest it. This accords with the observation that carrion-transmitted botulism in animals is usually caused by type C or D.
Genotypic evaluation of rickettsial isolates recovered from various species of ticks in Portugal
Authors: Bacellar F. , Regnery R. L. , Núncio M. S. , Filipe A. R. 
Published: May 2009

SUMMARYTwelve rickettsial isolates, fromRhipicephalus sanguineus, R. turanicus, Dermacentor marginatusandHyalomma marginatus, were subjected to genotypic analysis. Amplification of specific DNA sequences, restriction endonuclease digestion of amplified DNA products, and gel electrophoresis were used to identify specific DNA fragment-banding patterns. Five patterns were resolved. Four were homologous with those of previously described rickettsial genotypes,R. conorii, R. slovaca, R. rhipicephaliandR. massiliae. The fifth pattern differed by only a single altered restriction endonuclease cleavage site. For the first time in Portugal a widely distributed spectrum of spotted fever group rickettsia was found among potential vector species stressing the need to determine their potential for human and domestic animals infection.
An investigation of possible routes of transmission of lumpy skin disease virus (Neethling)
Authors: Carn V. M. , Kitching R. P. 
Published: May 2009

SUMMARYBritish cattle were infected with the South African (Neethling) strain of lumpy skin disease virus (LSDV) and their clinical signs monitored over a 3-week period. Different routes of infection were assessed for effect on the clinical characteristics of the disease by using a clinical scoring system. Neither of 2 animals inoculated onto the conjunctival sac showed clinical signs or seroconverted. The intradermal route produced local lesions in 21 of 25 animals, and generalized infection in 4. In contrast the intravenous route produced generalized lesions in 8 of 11 animals. Seven uninfected animals were housed in contact with infected animals for 1 month. None developed clinical signs or produced detectable serum neutralizing antibodies. Six of seven of these animals were then challenged and were fully susceptible to infection. The results suggest that the transmission of LSDV between animals by contagion is extremely inefficient, and that parenteral inoculation of virus is required to establish infection. The high proportion of animals with generalized disease following intravenous inoculation implies that naturally occurring cases of generalized LSD may follow spread by intravenously feeding arthropods.
Serosurvey and laboratory diagnosis of imported sandfly fever virus, serotype Toscana, infection in Germany
Authors: Schwarz T. F. , Jäger G. , Gilch S. , Pauli C. 
Published: May 2009

SUMMARYOf eight acute infections in German tourists caused by sandfly fever virus, serotype Toscana (TOS). and diagnosed clinically and serologically, seven were acquired during visits to Tuscany, Italy, and one to Coimbra, Portugal. An indirect immunofluorescence assay (IFA) using infected cells, and a newly developed enzyme-immunoassay (EIA) using crude virus antigen prepared from infected Vero-E6 cells was used to detect anti-TOS IgM and IgG. In a seroepidemiological survey of 859 health care workers and medical students, anti-TOS IgG was detected in 1·0% by IFA, and in 0·7% by EIA. In 2034 German patients hospitalized for various diseases, 1·6% were positive for anti-TOS IgG by IFA, and 0·8% by EIA. Anti-TOS IgG was detected in 43 samples of commercial immunoglobulins at titres of 10–1000 by EIA. Although the seroprevalence of antibodies to TOS is low in Germany, TOS infection should be considered in patients returning from endemic areas who complain of fever, and headaches, and have symptoms of meningitis.
Estimating the economic benefits of avoiding food-borne risk: is ‘willingness to pay’ feasible?
Authors: Donaldson C. , Mapp T. , Ryan M. , Curtin K. 
Published: May 2009

SUMMARYIn this paper, the results of a pilot study of willingness to pay (WTP) to avoid poultry-borne illness are reported. Through this, the problems of devising an economic measure of the ‘intangible’ benefits of prevention of food-borne risk are explored. The study is the first to allow those against a prevention policy (irradiation of poultry-meat) to register their WTP not to have the policy implemented. The study demonstrates that it is feasible to obtain answers to WTP questions from a self-selected sample. Future studies should ensure greater representativeness of respondents, that better information about benefits is provided to respondents and that an appropriate method of aggregation of benefits is used.
Thermal sensitivity ofClostridium botulinumtype C toxin
Authors: Hubálek Z. , Halouzka J. 
Published: May 2009

SUMMARYA sterile suspension containing 950 mouse LD50 per ml of type C botulinum toxin was exposed for various periods to different temperatures. The time required for the 99% (hundred-fold) reduction of toxicity was more than 5 years at -70°C or -20°C, 6 montha at +5 °C, 3 weeks at +20 °C, 2 weeks at +28 °C, 2 days at +37 °C, 9h at +42°C, less than 30 min at 56 °C, less than 20 min at +60 °C, and below 5 min at +80 °C. The results suggest thatClostridium botulinumtype C toxin, if produced in an ecosystem of the mild climatic zone, might persist there over the winter season and cause the intoxication of vertebrates next carly spring in the absence of further microbial toxigenesis.
The growth of salmonella in rumen fluid from cattle at slaughter
Authors: Mattila T. , Frost A. J. , O'Boyle D. 
Published: May 2009

SUMMARYThe pH of the rument contents of cattle was recorded at slaughter; pH ranged from 5.5 to 7–8 and was not correlated with the period from saleyard to slaughter. Volatile fatty acids (VFA) were measured in 43 rumen samples; acetic, propionic and butyric were the major acids present, and the total VFA ranged from 75·9 mM/1 for samples between pH 6–7, to 7·1 mM/1 for samples of pH 8–9. TenSalmonellastrains belonging to 8 serotypes were grown in these 43 rumen samples. Where acid levels of these samples were high and pH low, mostSalmonellasp. were inhibited: as the pH rose (pH 7–8) allSalmonellaserotypes grew, some vigorously; as the total acid declined and pH continued to rise, growth of salmonella ceased. Serotypes and strains of the same serotype differed in their ability to grow in rumen contents, particularly when the pH was low.
Experimental observations on the pathogenesis of necrobacillosis
Authors: Smith G. R. , Wallace L. M. , Noakes D. E. 
Published: May 2009

SUMMARYEarlier studies showed that the minimum infective dose (>106organisms) of a virulent strain ofFusobacterium necrophorumcould be greatly reduced by suspending the fusobacteria in sub-lethal doses of cultures of other bacteria such asEscherichia colibefore inoculating mice subcutaneously.In the present study the infective dose of the same strain ofF. necrophorumwas reduced by a factor of >103by suspending the fusobacteria in sub-lethal doses of 5% homogenate of gaur or wallaby faeces. Sterile faecal filtrate had no such effect. The sites of low grade infection produced by the prior subcutaneous injection ofE. coliculture or gaur faecal suspension were susceptible to superinfection by doses ofF. necrophorumfar below those required to infect normal tissue.This work helps to explain the production of necrobacillosis by the faecal contamination of small wounds. It proved impossible, however, to produce necrobacillosis in mice by the subcutaneous injection of faecal suspensions from 33 farm cattle. This suggests that the proportion of cattle with virulentF. necrophorumin their faeces is low.
Horizontal transmission ofCampylobacter jejuniamongst broiler chicks: experimental studies
Authors: Shanker S. , Lee A. , Sorrell T. C. 
Published: May 2009

SUMMARYHorizontal transmission ofCampylobacter jejuniwas investigated in campylobactor–free broiler chicks. One hundred and twenty chicks housed individually, were provided with water containing 102−109c.f.u./mlC. jejuni. Colonization was rapid [47 of 73 (64 %) positive cloacal cultures within 3 days and 65 of 73 (89 %) within 7 days], depenedent onC. jejuni–contaminated water or colonized seeder chicks. Transmission occurred in 2–7 days concurrent with a gradual increase ofC. jejuniin litter, water and feed. Environmental samples were culture–negative within 3 days following removal of colonized chicks. Treatment of 1–day–old chicks with adult caecal microbiota did not affect colonization. Treated and control chicks were allC. jejuni–positive within 3 days of seeder challenge.
The epidemiology of beta-haemolytic non-Group A streptococci isolated from the throats of children over a one-year period
Authors: Cimolai N. , MacCulloch L. , Damm S. 
Published: May 2009

SUMMARYThe incidence of beta-haemolytic non-Group A streptococci (BHNAS) in the throats of a paediatric population was examined over a 1-year period. There was minimal seasonal fluctuation of Lancefield groups including species and biotypes within Groups C and G streptococci. A trend of increasing incidence with age ofStreptococcus anginosus(‘Streptococcus milleri’) (possessing Groups C and G Lancefield antigens) was evident. A clinical impression of streptococcal pharyngitis was more common in patients with large-colony Groups C or G streptococci isolated from their throats compared with those patients where other BHNAS were isolated. This study is requisite to the planning of case control studies which are required to test the association of BHNAS (especially Groups C and G subgroups) and pharyngitis.
The epidemiological relationship between salmonella isolated from poultry meat and sewage effluents at a long-stay hospital
Authors: Reilly W. J. , Oboegbulem S. I. , Munro D. S. , Forbes G. I. 
Published: May 2009

SUMMARYBetween February 1988 and March 1989 chicken carcases delivered to the kitchen of a long stay psycho–geriatric hospital were screened every week for salmonella contamination. While 214 of 477 (45▒) individual carcases carried one or more salmonella types, every single consignment examined contained affected carcases.Simultaneously sewers draining the residential accommodation and excluding kitchen effluent, were also monitored. Thirty out of 79 (38▒) of Moore's swabs were positive for salmonella. There was a statistically significant association between the salmonella types isolated from chicken and those isolated from sewers the following week.Following a change in kitchen policy to order only cooked chicken there was a significant reduction in the isolation of salmonella from the sewers.
The influence of age on the response of SPF hens to infection with Salmonella enteritidis PT4
Authors: Humphrey T. J. , Chart H. , Baskerville A. , Rowe B. 
Published: May 2009

SUMMARYWhen Specific Pathogen–Free hens were infected with Salmonella enteritidis PT4 by direct administration into the crop, the age of the bird at infection was found to have an effect on both pathogenesis and antibody response. Birds at 20 weeks of age showed no adverse signs and developed high titres of antibodies of the IgM class, while those which were 1 year old at infection developed relatively little antibody arid had acute septicaemia, with 6 of 10 birds either dying or having to be humanely destroyed. The implication of these results for the control of salmonella infections in poultry is discussed.
Meningococcal carriage in close contacts of cases
Authors: Cartwright K. A. V. , Stuart J. M. , Robinson P. M. 
Published: May 2009

SUMMARYBetween 1 October 1986 and 31 March 1987, 55 cases of meningococcal disease were identified in the South-West of England, an attack rate of 1·54 per 100000 during the study period. Antibiotics used in the treatment of the disease successfully eliminated nasopharyngeal carriage of meningococci in 13 out of 14 cases without use of rifampicin. The overall meningococcal carriage rate in 384 close contacts was 18·2% and the carriage rate of strains indistinguishable from the associated case strain was 11·1%. The carriage rate of indistinguishable strains in household contacts (16·0%) was higher than the carriage rate in contacts living at other addresses (7·0%, P > 0·05). A 2·day course of rifampicin successfully eradicated meningococci from 46 (98%) of 47 colonized contacts.In one third of cases groupable meningococci were isolated from at least one household contact; 92% of these isolates were of the same serogroup as the associated case strain. When a meningococcus is not isolated from a deep site in a clinical case of meningococcal disease, culture of serogroup A or C strains from nasopharyngeal swabs of the case or of household contacts is an indication that the close contact group should be offered meningococcal A + C vaccine in addition to chemoprophylaxis. The failure in this and other studies to isolate meningococci from any household contact in the majority of cases may be due either to the relative insensitivity of nasopharyngeal swabbing in detecting meningococcal carriage or to the acquisition of meningococci by most index cases from sources outside the household.
Social and geographical risk factors inHelicobacter pyloriinfection
Authors: Whitaker C. J. , Dubiel A. J. , Galpin O. P. 
Published: May 2009

SummaryA correlation between childhood crowding and the later development of gastric cancer has been demonstrated by Barker and colleagues, who proposed that the relationship was the consequence of infection by an organism such asHelicobacter pylori. In order to test this hypothesis the presence of IgG antibodies toH. pyloriin sera from blood donors in North Wales has been investigated. During donation sessions, donors answered questions relating to social conditions and domicile in childhood (at age 10 years) and adult life (the preceding 2 years).A stepwise logistic regression analysis of the data demonstrated significant independent relationships between seropositivity and the following factors: sharing a bed in childhood, housing density, locality of birth, adult social class and age.
An analysis of the diversity ofHaemophilus parainfluenzaein the adult human respiratory tract by genomic DNA fingerprinting
Authors: Kerr G. R. D. , Forbes K. J. , Williams A. , Pennington T. H. 
Published: May 2009

SummaryA method for typingHaemophilusspecies is described, based on the analysis of genomic DNA fromHaemophilus parainfluenzae. The DNA was extracted by a rapid method and digested with the restriction enzymeBamHI to provide a characteristic ‘fingerprint’. The pattern of fragments in the ranges 1–1·6 kb, 1·6–2 kb and 2–3 kb were used to produce a numerical profile of each isolate. In total 97 isolates were examined; 88 from throat swab material isolated from the 15 members of a British Antarctic Survey base and 9 type strains. Seventy-two of the 88 antarctic isolates wereH. parainfluenzaeand were found to be very diverse, comprising 41 identifiable strains with up to 5 strains being isolated from a single throat swab sample. There was evidence for both carriage and transmission within the isolated community. The technique provided a highly discriminatory method for characterizingHaemophilusstrains which is suitable for epidemiological studies.