bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization of human faecal flora by means of an improved fluoro-morphometrical method
Authors: Jansen G.J. , Wilkinson M. H. F. , Deddens B. , Waaij D. Van Der
Published: May 2009

The use of polyclonal antibodies in differentiating between samples of faecal microflora derived from ten healthy volunteers was assessed. The distribution of FITC-labelled antibodies (of the IgA, IgG and IgM isotype) over 144 morphologically distinct subsets of faecal bacteria (‘morphotypes’) was quantified by means of digital morphometry and quantitative immunofluorescence. Furthermore, a new dataprocessing algorithm was developed which makes objective quantitation of the antibody distributions over the faecal morphotypes possible. The results of this study imply that the antibody binding capacity of faecal morphotypes is a unique characteristic of faecal microflora.
The problems of tracing a geographically widespread outbreak of salmonellosis from a commonly eaten food: Salmonella typhimurium DT193 in North West England and North Wales in 1991
Authors: Thornton L. , Gray S. , Bingham P. , Salmon R. L. , Hutchinson D. N. , Rowe B. , Newton D. , Syed Q. U.
Published: May 2009

Geographically widespread outbreaks involving commonly isolated organisms and where the vehicles of infection are commonly eaten foodstuffs pose particular difficulties at a technical and organizational level.

An outbreak of Salmonella typhimurium infection, affecting 39 people, spread over a wide area in North West England and North Wales in April and May 1991, was detected thanks to the practice of sending specimens to the national reference laboratory where phage typing and characterizing of antibiotic resistance patterns enabled the identification of a cluster of distinctive isolates (S. typhimurium DT193 resistant to sulphonamides, trimethoprim and furazolidone). An investigation, involving twenty environmental health departments in addition to health authorities and the Public Health Laboratory Service, showed an association between the illness and eating loose sliced cooked ham (P = 0.004). Detailed tracing of the chain of supply of the ham showed this to be particularly cooked ham originating from a single small local producer (P = 0.00003). Further investigation of that producer revealed that a batch of ham distributed on one day in early April was undercooked due to a malfunction in cooking equipment.
Antigenic and genetic analyses of influenza type B viruses isolated in Russia, 1987–91
Authors: Hemphill M. L. , Rota P. A. , Ivanova V. T. , Slepushkin A. N. , Kendal A. P.
Published: May 2009

Four influenza type B viruses isolated in Russia during periods of relatively low (1987–8) or high (1990–1) influenza B activity were characterized antigenically using a microneutralization assay. These isolates were antigenically similar to contemporary reference strains from either of two separate lineages represented by B/Victoria/2/87 and B/Yamagata/16/88. The evolutionary relationships of the variable portion of the haemagglutinin (HA1) genes of these viruses were determined by comparison with influenza B HA1 sequences previously obtained. The Isolate B/USSR/2/87, collected during the 1987–8 influenza season, was found to be closely related to viruses on the B/Victoria/2/87 lineage that circulated during the 1988–9 influenza season in the United States. Sequence analysis of the isolates from the 1990–1 influenza season demonstrated co-circulation of viruses from both the B/Victoria/2/87 and B/Yamagata/16/88 lineages in Russia, confirming the antigenic analysis.
Enzyme-linked immunosorbent assays for the detection of antibody to Crimean-Congo haemorrhagic fever virus in the sera of livestock and wild vertebrates
Authors: Burt F. J. , Swanepoel R. , Braack L. E. O.
Published: May 2009

IgM antibody response to Crimean-Congo haemorrhagic fever (CCHF) virus was monitored in experimentally infected sheep and cattle by an IgM capture enzyme-linked immunoassay (ELISA). Specific binding of antigen was detected by a rabbit anti-CCHF horseradish peroxidase conjugate or a sandwich technique with hyperimmune mouse anti-CCHF ascitic fluid and commercially available anti-mouse immunoglobulin peroxidase conjugate. The persistence of IgM antibody activity was found to be of shorter duration than in humans, and this may be a function of the relative lack of susceptibility of these animals to infection with CCHF virus. IgG antibody responses in the sheep could be monitoried by sandwich ELISA using commercially available anti-sheep immunoglobulin peroxidase conjugates. Total antibody activity in the sera of experimentally infected sheep, cattle and small mammals could be monitored in a competitive ELISA (CELISA) using rabbit anti-CCHF peroxidase conjugate. The CELISA was applied to the sera of 960 wild vertebrates from a nature reserve in South Africa, and the prevalence of antibody was found to be greatest in large mammals such as rhinoceros, giraffe and buffalo, which are known to be the preferred hosts of the adult tick (Hyalomma) vectors of the virus.
Dose–response effects in an outbreak of Salmonella enteritidis
Authors: Mintz E. D. , Cartter M. L. , Hadler J. L. , Wassell J. T. , Zingeser J. A. , Tauxe R. V.
Published: May 2009

The effects of ingested Salmonella enteritidis (SE) dose on incubation period and on the severity and duration of illness were estimated in a cohort of 169 persons who developed gastroenteritis after eating hollandaise sauce made from grade–A shell eggs. The cohort was divided into three groups based on self–reported dose of sauce ingested. As dose increased, median incubation period decreased (37 h in the low exposure group 21 h in the medium exposure group v. 17·5 h. in the high exposure group, P = 0.006) and greater proportions reported body aches (71 v. 85 v. 94%, P = 0.0009) and vomiting (21 v. 56 v. 57%, P = 0.002). Among 118 case-persons who completed a follow–up questionnaire, increased dose was associated with increases in median weight loss in kilograms (3.2 v. 4.5 v. 5.0, P = 0.0001), maximum daily number of stools (12.5 v. 15.0 v. 20.0, P = 0.02), subjective rating of illness severity (P = 0.0007), and the number of days of confinement to bed (3.0 v. 6.5, P = 0.04). In this outbreak, ingested dose was an important determinant of the incubation period, symptoms and severity of acute salmonellosis.
Bacteriophage typing inSalmonella bareilly
Authors: Sharma N. C , Bhatia R. , Singh S. , John P. C. , Kumar S. , Singh H.
Published: May 2009

A total of 675 stdrains ofSalmonella bareillyreceived from different parts of India and France during 1959–92 were phage typed using six bacteriophages. Overall ttypability achieved was 90·8% with 23 distinctphage types excluding a group of untypable strains. Phage types have been defined in octal code. Simpson's coefficient was applied for diversity index having a value of 0·839. This system was found to be reproducible, stable and epidemiologically useful.
Legionellaceae in the potable water of Nova Scotia hospitals and Halifax residences
Authors: Marrie T. , Green P. , Burbridge S. , Bezanson G. , Neale S. , Hoffman P. S. , Haldane D.
Published: May 2009

Water was cultured from 39 of 48 hospitals (7 Halifax hospitals and 32 non-Halifax hospitals) in the province of Nova Scotia and from 90 residences (74 private dwellings, 16 apartments) in Halifax to determine the frequency of legionella contamination. Six of seven Halifax hospitals had Legionellaceae isolated from their potable water compared with 3 of 32 non-Halifax hospitals (P < 0.0001). Overall. 19 of 59 (32%) of the water samples from Halifax hospitals were positive for legionellae compared with 5 of 480 (1%) samples from non-Halifax hospitals (P < 0.0000). Five of the six positive Halifax hospitals hadLegionella pneumophilaserogroup 1 and 1 hadL. longbeachaeserogroup 2 recovered from their potable water. Legionella contamination was associated with older, larger (> 50 beds) hospitals with total system recirculation. These hospitals also had water with a higher pH and calcium content but lower sodium, potassium, nitrate, iron and copper content.

Fourteen of the 225 (6.2%) water samples from Halifax residences were positive for legionellae – 8% (6/74) of the single family dwellings were positive, compared with 25% (4/16) apartments. The positivity rate of 15.7% for the 19 electric hot-water heaters in Halifax homes was not significantly different from the 32% positivity for Halifax hospitals.L. longbeachaeaccounted for 2 of the 14 isolates of legionellae from Halifax homes.
Seroprevalence of hepatitis B and C in a Merseyside hospital for the mentally handicapped
Authors: Cunningham S. J. , Cunningham R. , Izmeth M. G. A. , Baker B. , Hart C. A.
Published: May 2009

This study reports the prevalence of antibodies to hepatitis B virus (HBV) and C virus (HCV). and the frequency of potential exposure to these viruses among patients and staff in six long-stay wards of a hospital caring for mentally handicapped adults from the Mersey region. A retrospective survey of risk behaviour among 134 patients and questionnaire survey of 75 nursing staff was performed. Serum samples from both groups were tested for HBV markers and patient sera for antibodies to HCV by enzyme-linked immunosorbent assay (ELISA). None of the 102 patients tested had antibodies against HCV. although 17 had detectable antibody to HBV core (anti-HBc). Seven out of the 17 were positive for HBV surface antigen. None was positive for IgM antibody to HBV core. Only 1 out of 61 staff had anti-HBc and none was positive for surface antigen. Twenty-nine of 75 (39%) staff reported bites sufficient to break the skin and 52 (69%) significant other injuries from patients; 25 (31%) of staff had not received HBV vaccination. None of the patients had received HBV vaccine.

We conclude that HCV does not appear to be a major hazard in this closed community but the prevalence of HBV markers indicating past exposure among patients is high, vaccine uptake is incomplete and incidents which may allow viral transmission are frequent.
An outbreak of diarrhoeal disease attributed to Shigella sonnei
Authors: Samonis G. , Elting L. , Skoulika E. , Maraki S. , Tselentis Y.
Published: May 2009

An outbreak of gastroenteritis occurred in a village on the Island of Crete, with 1479 inhabitants. One hundred and thirty–eight symptomatic patients from 57 different families were examined. Thirty percent of children under 12 years were affected compared with 4% of adolescents and adults (P < 0.0001). Thirty–five out of 105 stool cultures (33%) grew Shigella sonnei. Thirty–four isolates had the same susceptibility pattern and were sensitive to ampicillin, while one was resistant to this antibiotic. Thirty–three isolates had the same plasmid profile. Based on epidemiologic and environmental findings, it was concluded that the transmission of shigellosis was waterborne. Shigella were not isolated from water, but one of the three village springs was found to be contaminated with faecal coliforms. This spring was probably contaminated by sewage material, due to its proximity to a source of untreated sewage effluent. Implementation of environmental and control measures brought the epidemic to an end.
In vivoR–plasmid transfer in a patient with a mixed infection of shigella dysentery
Authors: Bratoeva M. P. , John. J. F.
Published: May 2009

Transfer of shigella R–plasmidsin vivohas seldom been demonstrated. Strains ofShigella dysenteriaetype 1 andShigella flexneritype 5b were isolated from a Bulgarian traveller who visited Vietnam and developed dysentery, which was treated with trimethoprim/sulfamethoxazole (TMP/SMZ) for a short time. Both species of shigellae are unusual in Bulgaria where strains ofS. sonneipredominate. Both shigella strains were multiresistant to the same antimicrobial agents. Each strain contained a 48–kilobase plasmid that conferred the entire resistance phenotype to a susceptibleEscherichia coli. Restriction endonuclease patterns of plasmid DNA from the respective strains were identical. Transmissible plasmids of the same resistance phenotypes and restriction patterns were isolated from the patient's colonicE. coli. Transconjugants hybridized to a dihydrofolate reductase type I–DNA probe. These studies support the hypothesis that R–plasmid transfer may occur between non-pathogenic, faecal strains and pathogenic shigellae, a process that may have been facilitated by inadequate treatment with TMP/SMZ at the onset of the illness.
Lyme disease: a search for a causative agent in ticks in south–eastern Australia
Authors: Russell R. C. , Doggett S. L. , Munro R. , Ellis J. , Avery D. , Hunt C. , Dickeson D.
Published: May 2009

Attempts were made to identify the causative organism of Lyme disease in Australia from possible tick vectors.

Ticks were collected in coastal areas of New South Wales, Australia, from localities associated with putative human infections. The ticks were dissected; a portion of the gut contents was examined for spirochaetes by microscopy, the remaining portion inoculated into culture media. The detection of spirochaetes in culture was performed using microscopy, and immunochemical and molecular (PCR) techniques. Additionally, whole ticks were tested with PCR for spirochaetes.

From 1990 to 1992, approximately 12000 ticks were processed for spirochaetes. No evidence ofBorrelia burgdorferior any other spirochaete was recovered from or detected in likely tick vectors. Some spirochaete–like objects detected in the cultures were shown to be artifacts, probably aggregates of bacterial flagellae.

There is no definitive evidence for the existence in Australia ofB. burgdorferithe causative agent of true Lyme disease, or for any other tick–borne spirochaete that may be responsible for a local syndrome being reported as Lyme disease.
Landfill sites, botulism and gulls
Authors: Ortiz N. E. , Smith G. R.
Published: May 2009

Botulism due toClostridium botulinumtype C causes considerable mortality in gulls in the UK, and refuse disposal sites are suspected as a major source of toxin.C. botulinumtypes B, C and D were each found in 12 (63.2%) of 19 landfill sites examined. Type E was detected in only one (5.2%) and types A, F and G were not found. The prevalence of type C spores was much higher than that demonstrated in the UK environment by earlier surveys. The presence of these spores, together with the rotting organic matter and generated heat associated with landfill sites, undoubtedly leads to bacterial proliferation and toxigenesis. This is likely to result in botulism in scavenging gulls unless skilled landfill management prevents the ingestion of toxic material. Type D spores were previously shown to be rare in the UK environment and their high prevalence on landfill sites was therefore surprising. Four composite samples of refuse collected before distribution on a landfill gave negative results forC. botulinumand it seems likely that the gulls themselves play a major role in introducing contamination.
Epidemic cholera in rural El Salvador: risk factors in a region covered by a cholera prevention campaign
Authors: Quick R. E. , Thompson B. L. , Zuniga A. , Dominguez G. , De Brizuela E. L. , De Palma O. , Almeida S. , Valencia A. , Ries A. A. , Bean N. H. , Blake P. A.
Published: May 2009

In response to the Latin American cholera epidemic, El Salvador began a prevention programme in April 1991. The first case was confirmed in August, and 700 cases were reported within 3 months. A matched case-control study was conducted in rural La Libertad Department in November 1991. Illness was associated with eating cold cooked or raw seafood (odds ratio [OR] = 7·0; 95% confidence limits [CL] = 1·4, 35·0) and with drinking water outside the home (OR = 8·8; 95% CL = 1·7, 44·6). Assertion of knowledge about how to prevent cholera (OR = 0·2; 95% CL = 0·1, 0·8) and eating rice (OR = 0·2; 95% CL = 0·1, 0·8) were protective. More controls than patients regularly used soap (OR = 0·3; 95% CL = 0·1, 1·0). This study demonstrated three important points for cholera prevention: (1) seafood should be eaten cooked and hot; (2) populations at risk should be taught to treat household drinking waterandto avoid drinking water outside the home unless it is known to be treated; and (3) education about hygiene can be an important tool in preventing cholera.
The effect of CMV infection on progression of human immunodeficiency virus disease in a cohort of haemophilic men followed for up to 13 years from seroconversion
Authors: Sabin C. A. , Phillips A. N. , Lee C. A. , Janossy G. , Emery V. , Griffiths P. D.
Published: May 2009

The effect of prior infection with cytomegalovirus (CMV) on progression of HIV disease in a cohort of 111 men with haemophilia was studied after 13 years followup. The relative hazards associated with CMV positivity on progression to AIDS, death and a CD4 count of 0·05 × 109/1 were 2·28, 2·42 and 2·34, respectively. CMV seropositive patients were significantly older than the seronegative and this was controlled for by using a Cox proportional hazards model. The relative hazards for the three endpoints decreased to 1·89, 1·82 and 1·93 respectively and were marginally non-significant (P = 0·05, 0·08 and 0·08 for the three endpoints respectively). We conclude that this cohort continues to show evidence of a ‘co-factor’ effect associated with prior infection with CMV which is confounded by age but not completely explained by age differences. The potential biological significance of these results is discussed in the context of recent controlled clinical trials which show a survival benefit from long-term high-dose acyclovir, a drug with activity in vivo against CMV and other herpesviruses.
The Public Health Laboratory Service national case-control study of primary indigenous sporadic cases of campylobacter infection
Authors: Adak G. K. , Cowden J. M. , Nicholas S. , Evans H. S.
Published: May 2009

The aetiology of sporadic campylobacter infection was investigated by means of a multicentre case-control study. During the course of the study 598 cases and their controls were interviewed.

Conditional logistic regressional analysis of the data collected showed that occupational exposure to raw meat (odds ratio [OR] 9·37; 95 % confidence intervals [CI] 2·03, 43·3), having a household with a pet with diarrhoea (OR 2·39; CI 1·09. 5·25), and ingesting untreated water from lakes, rivers and streams (OR 4·16; CI 1·45. 11·9) were significant independent risk factors for becoming ill with campylobacter. Handling any whole chicken in the domestic kitchen that had been bought raw with giblets, or eating any dish cooked from chicken of this type in the home (OR 0·41–0·44; CI 0·24, 0·79) and occupational contact with livestock or their faeces (OR 0·44; CI 0·21, 0·92) were significantly associated with a decrease in the risk of becoming ill with campylobacter.
Infecting dose and severity of typhoid: analysis of volunteer data and examination of the influence of the definition of illness used
Authors: Glynn J. R. , Hornick R. B. , Levine M. M. , Bradley D. J.
Published: May 2009

Data from volunteers challenged with Salmonella typhi were reanalysed to explore the relationship between challenge dose and severity of disease. Among 120 ill volunteers who received between 105 and 109 organisms, dose was weakly correlated with peak temperature (r = 0·22, 95% CI 0·04–0·39), duration of temperature above 103 °F (39·4 °C: r = 0·13, 95% CI –0·03 to 0·55) and symptom score (r = 0·27, 95% CI 0·09–0·43). The association with symptom score was lost after adjusting for year, and the findings depended on the definition of illness used: with stricter definitions the associations with temperature were also lost. The study shows the need for caution in interpreting the relationship between dose and severity of disease.
Carriage ofStaphylococcus aureusamong 104 healthy persons during a 19-month period
Authors: Eriksen N. H.Riewerts , Espersen F. , Rosdahl V.Thamdrup , Jensen K.
Published: May 2009

The present study was undertaken to investigate the frequency of the nasal carrier rate ofStaphylococcus aureus. The investigation was performed on 104 healthy persons. The total number of swabs performed was 1498 and this resulted in isolation of 522S. aureusstrains. All strains have been identified, tested for antibiotic susceptibility, and phage-typed. The carrier-index (number of positive swabs/number of total swabs for each individual person) was compared with different sampling and culturing methods, phage type, age, and resistance to antibiotics. There was statistical difference in carrier rate according to sex (P·05). Among the 104 persons 15 (14·4%) were persistent carriers, 17 (16·3%) intermittent carriers, 55 (52·9%) occasional carriers and 17 (16·3%) non-carriers. Among intermittent and occasional carriers the phage-type distribution was different from theS. aureusstrains isolated from Danish hospitalized patients in 1992, while the persistent carriers had similar phage-type distribution.
An outbreak of waterborne cryptosporidiosis associated with a public water supply in the UK
Authors: Atherton F. , Newman C. P. S. , Casemore D. P.
Published: May 2009

In November and December 1992, an outbreak of waterborne cryptosporidiosis occurred in Bradford, a city in the North of England. In all 125 cases were involved, the majority of whom lived in part of the city which received its drinking water supply from a single water treatment works. A case control study demonstrated an association between illness and the consumption of tapwater from this source; those drinking large volumes being more likely to have been ill. Treated water from the defined source yielded cryptosporidial oocysts. Heavy rainfall was recorded in the catchment area of the reservoir supplying raw water to the treatment works, immediately prior to the probable time of infection, based on dates of onset of illness.
β-Lactam resistance in normal faecal flora from South Africa
Authors: Shanahan P. M. A. , Thomson C. J. , Amyes S. G. B.
Published: May 2009

The genetic and biochemical basis of ampicillin resistance amongst the aerobic Gram-negative commensal faecal flora of healthy volunteers in South Africa has been determined. Amongst 608 ampicillin resistant strains isolated from 320 of the participants, 158 were able to transfer their ampicillin resistant determinants intoEscheriehia coliK-12 J62–2. Iso-electric focusing of the β-lactamases, extracted from the transconjugants, demonstrated that ampicillin resistance resulted from the presence of the TEM-1, TEM-2 and SHV-1 β-lactamases in 94·3%, 2·5% and 3·2% of isolates respectively. Endonuclease restriction digests of the plasmids isolated from the transconjugants showed that the β-lactamase genes were present on a wide variety of plasmid types; 101 distinct plasmid endonuclease restriction patterns were identified. Transferable ampicillin resistance was associated with resistance to other antibiotics at the following frequencies: trimethoprim (48·7 %), streptomycin (35·4 %), tetracycline (27·2%), spectinomycin (9·5%), chloramphenicol (3·2%) and gentamicin (1·3%). One antibiotic resistance pattern, ampicillin and trimethoprim. predominated (28%). In total. 77·9% of the plasmids conferred resistance to other antibiotics raising the possibility that use of any of these agents, not simply ampicillin, may contribute to the maintenance of resistance genes.
Priorities in global measles control: report of an outbreak in N'Djamena, Chad
Authors: Ndikuyeze A. , Cook A. , Cutts F. T. , Bennett S.
Published: May 2009

In N'Djamena, capital of Chad, measles vaccination coverage of 12–23-month-old children fell from 61% in 1990 to 15% in 1993. A community survey of measles after an outbreak in 1993 showed that among children < 5 years of age, the mean monthly attack rate was 37 per 1000 (95% CI, 32–43) and the mean case fatality rate was 7·4%. Measles incidence was highest (77/1000/month) in children aged 9–11 months and fell among children > 3 years of age. Incidence rates were high (56/1000/month) among 6–8-month-old children, but only 3 deaths occurred in this age group. Measles vaccine efficacy, estimated by comparing attack rates in unvaccinated and vaccinated children, was 71 % (95% CI, 59–80%). Extrapolation of the results to the city population indicated that an estimated 19000 cases and > 1000 measles-associated deaths occurred in 1993. This preventable morbidity and mortality, in a city where coverage was formerly among the highest in Africa, shows the need for sustained global commitment to preventive health care.
The development of an age structured model for schistosomiasis transmission dynamics and control and its validation forSchistosoma mansoni
Authors: Chan M. S. , Guyatt H. L. , Bundy D. A. P. , Booth M. , Fulford A. J. C. , Medley G. F.
Published: May 2009

Mathematical models are potentially useful tools to aid in the design of control programmes for parasitic diseases. In this paper, a fully age structured epidemiological model of human schistosomiasis is developed and parameterized, and used to predict trends in infection prevalence, intensity and prevalence of heavy infections over age and time during several rounds of mass and age targeted treatment. The model is validated against data from aSchistosoma mansonicontrol programme in Kenya.
Antibiotic susceptibility of campylobacter isolates from sewage and poultry abattoir drain water
Authors: Koenraad P. M. F. J. , Jacobs-Reitsma W. F. , Van Der Laan T. , Beumer R. R. , Rombouts F. M.
Published: May 2009

In this study, thein vitrosusceptibility of 209 campylobacter strains to the quinolones nalidixic acid, flumequine, ciprofloxacin, enrofloxacin, and to ampicillin, tetracycline and erythromycin was tested by the disk diffusion method. The strains were isolated from poultry abattoir effluent (DWA) and two sewage purification plants (SPA and SPB). Sewage purification plant SPA received mixed sewage, including that from a poultry abattoir, whereas SPB did not receive sewage from any meat-processing industry. The quinolone resistance of the DWA isolates ranged from 28% for enrofloxacin to 50% for nalidixic acid. The strains isolated from the sewage purification plants were more susceptible to the quinolones with a range of 11–18% quinolone resistance for SPB isolates to 17–33% quinolone resistance for SPA isolates. The susceptibility criteria as recommended by National Committee Clinical Laboratory Standards (USA) cannot readily be employed for campylobacter isolates. This investigation shows that the resistance of campylobacter bacteria is highest in the plant receiving sewage from a poultry slaughterhouse. Monitoring of antibiotic resistance of aquaticCampylobacterspp. is important, as surface waters are recognized as possible sources of infection.
Nationwide outbreak of human salmonellosis in Germany due to contaminated paprika and paprika-powdered potato chips
Authors: Lehmacher A. , Bockemühl J. , Aleksic S.
Published: May 2009

Between April and September 1993, a nationwide outbreak of salmonellosis occurred in Germany which was traced to contaminated paprika and paprika-powdered potato chips. Of the estimated 1000 cases, children below 14 years were principally affected. Levels of 0·04–0·45 organisms per gram were found in the snacks. The infective dose was estimated at 4–45 organisms with an attack rate of 1 in 10000 exposed persons. The unique feature of the outbreak was the variety of serovars involved. S. saintpaul, S. rubislaw and S. javiana were isolated during the same time period from paprika powder, spice mixtures, snacks and patients. Their clonal identity was confirmed by molecular typing methods. Furthermore, monophasic and non-motile strains of rare salmonella O-groups were isolated from both paprika products and patients. This is the largest documented outbreak due to contaminated spices which proved that even extremely low numbers of salmonellae adapted to the dry state were able to cause illness.
An outbreak of cryptosporidiosis associated with a resort swimming pool
Authors: MacKenzie W. R. , Kazmierczak J. J. , Davis J. P.
Published: May 2009

An outbreak of cyptosporidiosis occurred in late April 1993 among resort hotel guests which was temporally associated with, but geographically distant from, a massive waterborne outbreak of cryptosporidiosis in Milwaukee, Wisconsin, that occurred in late March and early April of 1993. A case-control study was performed among groups with members who reported illness and among a systematic sample of groups who stayed at the resort hotel during the risk period. Of 120 persons interviewed, 51 (43%) met the case definition. Swimming in the resort hotel's pool was significantly associated with case status (OR = 9·8; 95% Cl 3·4, 29·7), as was consumption of ice from the hotel's ice machines (OR = 2·3; 95% Cl 1·01, 5·2). When analysis was restricted only to laboratory-confirmed cases and controls, swimming pool use was the only risk factor significantly associated with illness (OR=13·0; 95%C1 2·6, 88·7). Following waterborne outbreaks of cryptosporidiosis associated with water supplies, swimming pools should be considered as possible ongoing sources for transmission regionally.
Outbreak of cryptosporidiosis associated with a disinfected groundwater supply
Authors: Bridgman S. A. , Robertson R. M. P. , Syed Q. , Speed N. , Andrews N. , Hunter P. R.
Published: May 2009

In an outbreak of cryptosporidiosis in Warrington. a town in North-West England. 47 cases were recorded between November 1992 and February 1993. most within the first month. There was a strong statistical association between cases and residence in an area supplied from two groundwater sources. In a case-control study, a strong association between having drunk unboiled tap water from these sources, and a dose-response relationship were found. Oocysts were not detected in the water supply. During very heavy rainfall one source of water was found to drain surface water directly from a field containing livestock faeces, thereby bypassing natural sandstone filtration. Exceptionally heavy rainfall occurred at the probable time of infection. After withdrawal of the original water supply, the outbreak rapidly subsided. It was concluded that there was very strong evidence that this outbreak was waterborne. This, the second documented outbreak of cryptosporidiosis attributable to a groundwater supply, demonstrates that infection can be transmitted from a disinfected groundwater source despite apparently satisfactory treated water quality. We recommend that guidelines for protection of groundwater are implemented, raw groundwater should be routinely monitored for microbiological contamination, and the structure of all sources and waterworks should be assessed in risk surveys of water catchment areas.
Association between clinical presentation, biogroups and virulence attributes ofYersinia enterocoliticastrains in human diarrhoeal disease
Authors: Burnens A. P. , Frey A. , Nicolet J.
Published: May 2009

Traditionally the enteric pathogenYersinia enterocoliticahas been differentiated into biogroups. Despite being considered as non-pathogenic, biogroup 1A isolates have constituted a sizeable fraction of strains from patients with gastroenteritis in many reports. To establish a potential clinical significance for biogroup 1A isolates ofY. enterocolitica, clinical disease in patients with gastroenteritis excreting such isolates was compared with symptoms among patients found infected with pathogenic biogroups. Clinical data and isolates of 66 patients from whomY. enterocoliticahad been isolated by direct plating were available for study. There was an association between patient age below 3 years and infection with ‘pathogenic’Y. enterocolitica. The severity of gastroenteritis and other symptoms, however, did not depend on the biogroup, or the presence of the virulence plasmid in the yersinia strain isolated from the patients. Strains belonging to biogroup 1A ofY. enterocoliticashowed two clusters of ribotypes, one of which encompassed most isolates recovered from humans, the other being associated with environmental isolates. This might indicate the existence of human-adapted and potentially pathogenic strains among biogroup 1A ofY. enterocolitica.
The transmission dynamics of hepatitis B in the UK: a mathematical model for evaluating costs and effectiveness of immunization programmes
Authors: Williams J. R. , Nokes D. J. , Medley G. F. , Anderson R. M.
Published: May 2009

Complex hepatitis B (HBV) epidemiology makes it difficult to evaluate and compare effectiveness of different immunization policies. A method for doing so is presented using a mathematical model of HBV transmission dynamics which can represent universal infant and adolescent vaccination strategies and those targeted at genito-urinary (GU) clinic attenders and infants born to infectious mothers. Model structure, epidemiological underpinning, and parameterization, are described. Data from the UK National Survey of Sexual Attitudes and Lifestyles is used to define patterns of sexual activity and GU clinic attendance; data deficiencies are discussed, in particular that of UK seroprevalence of HBV markers stratified by age, sex, and risk factors. General model predictions of endemic HBV marker prevalence in homosexual and heterosexual populations seem consistent with published UK data. The simulations exhibit non-linearities in the impact of different vaccination strategies. Estimated number of carriers prevented per vaccine dose for each strategy provides a measure of costs and benefits, varying temporally over the course of a programme, and with level of vaccine coverage. Screening before vaccination markedly increases payback per dose in homosexuals but not in heterosexuals; mass infant vaccination gives the poorest effectiveness ratio and vaccination of infants after antenatal screening the best; in general, increasing vaccine coverage yields lower pay-back per dose. The model provides a useful framework for evaluating costs and benefits of immunization programmes, but for precise quantitative comparison more UK epidemiological data is urgently needed.
Relative abundance of enterovirus serotypes in sewage differs from that in patients: clinical and epidemiological implications
Authors: Hovi T. , Stenvik M. , Rosenlew M.
Published: May 2009

One thousand one hundred and sixty-one non-polio enterovirus strains, isolated during regular screening of Finnish sewage specimens, were analysed for serotype distribution seasonally through 20 years, and the findings were compared with similar data based on 1681 clinical isolates. Coxsackievirus B4 (CBV-4), CBV-5, echovirus 11 (EV-11), EV-6, CBV-2 and CBV-3 were the most common serotypes in sewage, whilst CBV-5, EV-11, coxsackievirus A9, EV-22, CBV-3 and EV-30 were the most common clinical isolates. Reasons for the differences are not known but several explanations are possible. Seasonal variation of enterovirus occurrence in both sources showed an expected peak in the autumn with a trough in the spring. The occurrence of enteroviruses was closely correlated with monthly recordings of mean relative humidity. A further observation concerning the clinical specimens in Finland was the relative excess of some serotypes, such as echovirus 22 and coxsackievirus A9, and paucity of others, for instance, echoviruses 4 and 9, when compared to published data from other countries. This is consistent with the idea of geographically restricted circulation of enteroviruses.
Listeriaspecies in domestic environments
Authors: Beumer R. R. , te Giffel M. C. , Spoorenberg E. , Rombouts F. M.
Published: May 2009

Using a direct isolation methodListeriaspp. were detected in 101 (47·4%) of 213 houses investigated.L. monocytogeneswas present in 45 houses (21·1%).Listeriaspp. occurred at all sampling sites. Dish-cloths (37%) and surface samples round the drain in the bathroom (27·2%) were most frequently contaminated. Highest numbers (c. 104c.f.u./object) were found in dish-cloths and washing-up brushes. Lower levels (up to 103c.f.u./object) were obtained from kitchen sinks, refrigerator vegetable compartment samples and tooth brushes. In total, 132 isolations ofListeriaspp. were made from 871 samples.L. innocua(53%) andL. monocytogenes(41%) were the predominant species in the positive samples. OtherListeriaspp. were found in only 6% of the positive samples.
Viral meningitis due to echovirus types 6 and 9: epidemiological data from Western Australia
Authors: Ashwell M. J. S. , Smith D. W. , Phillips P. A. , Rouse I. L.
Published: May 2009

During the autumn of 1992, Western Australia experienced a large viral meningitis outbreak of dual aetiology. Of the 161 cases, 64% were children under 15 years of age, with the highest notification rate being in children less than 5 years of age. Echovirus 9 caused 41% of cases and occurred mainly in the metropolitan areas of Western Australia whereas echovirus 6, which caused 37% of cases, was more widespread. An enterovirus was cultured from 70% of CSF specimens, 88% of faecal specimens and 68% of upper respiratory tract specimens. High CSF white cell counts and neutrophil predominance were common. Seven cases had normal CSF white cell counts even though an enterovirus was isolated from the CSF. Therefore, the CSF findings were of restricted value in excluding viral meningitis, and did not reliably distinguish between bacterial and viral meningitis.
Detection of four species ofBorrelia burgdorferisensu lato inIxodes ricinusticks collected from roe deer (Capreolus capreolus) in the Netherlands
Authors: Rijpkema S. G. T. , Herbes R. G. , Verbeek-De Kruif N. , Schellekens J. F. P.
Published: May 2009

Roe deer (Capreolus capreolus) were investigated for their value as sentinel animals for Lyme borreliosis in the Netherlands. Serum was obtained from 114 roe deer, and 513Ixodes ricinus, predominantly females (72%), were obtained from 47 animals (41%). The polymerase chain reaction was used to detect DNA ofBorrelia burgdorferisensu lato in a total of 190 ticks, comprising 106 engorged ticks and 84 non-engorged ticks. Borrelia DNA was detected in 24 engorged ticks (23%) and 26 non-engorged ticks (31%). This difference was not significant (P = 0·25). Four species ofB. burgdorferisensu lato were identified in the ticks:B. burgdorferisensu stricto,Borrelia garinii, Borrelia afzeliiand group VS116.B. afzeliiwas most commonly found and present in 13 mixed infections, and in 28 single infections. Fifteen sera (13%) contained antibodies toBorreliaspp. Ticks are more appropriate sentinel animals for Lyme borreliosis than roe deer, an important host forI. ricinus. Although the viability of borrelia spirochaetes in engorged ticks collected from roe deer was not assessed, a bloodmeal taken from roe deer did not eliminate borrelia spirochaetes from the tick. The relevance of this finding for transovarial transmission of borrelia spirochaetes in ticks is discussed.
Human listeriosis in Britain, 1967–85, a summary of 722 cases: 1. Listeriosis during pregnancy and in the newborn
Authors: McLauchlin J.
Published: May 2009

Clinical information was collected on 722 cases ofListeria monocytogenesinfections in humans occurring in Britain between 1967 and 1985: 248 cases (34%) were associated with pregnancy (maternal, foetal, and neonatal), and comprised 9 cases (4%) of maternal bacteraemia without infection of the foetus; 42 cases (19%) of intra-uterine deaths; 118 cases (54%) of neonatal infection diagnosed within 2 days post-partum; and 50 cases (23%) of neonatal infection diagnosed as ill after 2 days post-partum. An overall mortality of 50% was recorded.

The cases unassociated with pregnancy are described elsewhere (see accompanying paper).
An outbreak of Salmonella saint-paul infection associated with beansprouts
Authors: O'Mahony M. , Cowden J. , Smyth B. , Lynch D. , Hall M. , Rowe B. , Teare E. L. , Tettmar R. E. , Rampling A. M. , Coles M. , Gilbert R. J. , Kingcott E. , Bartlett C. L. R.
Published: May 2009

In March 1988, there was an outbreak of infection by a strain of Salmonella saint-paul with a distinctive antigenic marker. A total of 143 reports were received between 1 March and 7 June. Preliminary investigations suggested that raw beansprouts were a possible source of infection and a case-control study confirmed the association. S. saint-paul of the epidemic type was isolated from samples of beansprouts on retail sale in different cities in the United Kingdom and from mung bean seeds on the premises of the producer who was most strongly associated with cases. In addition, Salmonella virchow PT34 was isolated from samples of raw beansprouts and was subsequently associated with seven cases of infection. Four other serotypes of salmonella were also isolated from beansprouts. On 8 April the public were advised to boil beansprouts for 15 seconds before consumption, and the premises of the one producer associated with many cases were closed. As a result of these actions there was a significant decrease in the number of infections with S. saint-paul.
Serologically proven acute rubella infection in patients with clinical diagnosis of dengue
Authors: Bustos J. , Hamdan A. , Loroño M. A. , Montero M. T. , Gómez B.
Published: May 2009

Patients with a clinical diagnosis of dengue but negative by serological testing were studied for rubella infection. Paired sera were obtained from 69 patients during an outbreak in Yucatán, México. The presence of specific anti-viral IgM in the acute sera was considered as diagnostic for rubella infection. The immunoglobulin was determined by measuring the difference in the inhibition of hemagglutination between the non-reduced and the reduced fractionated sera. Immunoglobulins were separated by sucrose density centrifugation. Acute rubella infection was found in 7 (10·1%) of the patients. These results demonstrate active rubella infection in patients clinically diagnosed as dengue.
Introduction and Comments
Authors: Johnson James
Published: May 2009

We open this issue with a vigorous exchange on a matter that, to put it mildly, is politically fraught. In a series of provocative publications beginning in 2006, John Mearsheimer and Stephen Walt address what they call “the Israel Lobby” and detail what they see as the dire consequences that that lobby has generated for American foreign policy making. In our lead essay here, Robert Lieberman challenges Walt and Mearsheimer in precisely the way I think debate on their thesis needs to proceed. Lieberman focuses on the causal claims Walt and Mearsheimer advance, the evidence they adduce for those claims, and the ways that their arguments fit with established research on how American politics operates. Mearsheimer and Walt have written a spirited response to Lieberman who, in turn, offers a brief reply. It is safe to say that neither party to this exchange has persuaded the other. Yet, though their exchange is frank, both Lieberman and Mearsheimer and Walt keep their eye on the ball—they are concerned to establish whether and to what extent the Israel lobby exists and operates in the way Mearsheimer and Walt claim it does.
The “Israel Lobby” and American Politics
Authors: Lieberman Robert C.
Published: May 2009

In their recent book,The Israel Lobby and U.S. Foreign Policy,John Mearsheimer and Stephen Walt argue that American support for Israel does not serve American interests. Nevertheless, they observe that American foreign policy regarding the Middle East, especially in recent years, has tilted strongly toward support for Israel, and they attribute this support to the influence of the “Israel lobby” in American domestic politics. Their book is principally an attempt to make a causal argument about American politics and policymaking. I examine three aspects of this argument—its causal logic, the use of evidence to support hypotheses, and the argument's connection with the state of knowledge about American politics—and conclude that the case for the Israel lobby as the primary cause of American support for Israel is at best a weak one, although it points to a number of interesting questions about the mechanisms of power in American politics. Mearsheimer and Walt's propositions about the direct influence of the Israel lobby on Congress and the executive branch are generally not supported by theory or evidence. Less conclusive and more suggestive, however, are their arguments about the lobby's apparent influence on the terms and boundaries of legitimate debate and discussion of Israel and the Middle East in American policymaking. These directions point to an alternative approach to investigating the apparent influence of the Israel lobby in American politics, focusing less on direct, overt power over policy outcomes and more on more subtle pathways of influence over policy agendas and the terms of policy discourse.
Chasing the chimera
Authors: Norrie Kenneth McK.
Published: May 2009

During the 2008 US Presidential election, voters in California, as well as choosing a president, were asked to withdraw the right of same-sex couples to marry, the Californian Supreme Court having, six months previously, conferred that right by judicial decision.1 ‘Proposition 8’ aimed to restore the definition of marriage to its historical heterosexual limitations, and it passed, by a fairly narrow margin. The feature most remarkable to an outsider during the Proposition 8 campaign was the stunningly apocalyptical terms in which the debate was conducted, on both sides of the argument. The same-sex marriage debate is in the United States of America conducted in such venomous terms as to leave a European observer quite breathless. Nancy Polikoff’s latest book brings some calm to the discussion. It is a measured and thoughtful contribution to the debate and, though she does not directly address the question of why it is so much more contentious in the US than in other Western jurisdictions, her analysis does shed much light on that puzzling question. There are three main explanations that spring out of this engaging book.
Structural basis for the nuclease activity of a bacteriophage large terminase
Authors: Smits Callum , Chechik Maria , Kovalevskiy Oleg V , Shevtsov Mikhail B , Foster Andrew W , Alonso Juan C , Antson Alfred A
Published: May 2009

The DNA‐packaging motor in tailed bacteriophages requires nuclease activity to ensure that the genome is packaged correctly. This nuclease activity is tightly regulated as the enzyme is inactive for the duration of DNA translocation. Here, we report the X‐ray structure of the large terminase nuclease domain from bacteriophage SPP1. Similarity with the RNase H family endonucleases allowed interactions with the DNA to be predicted. A structure‐based alignment with the distantly related T4 gp17 terminase shows the conservation of an extended β‐sheet and an auxiliary β‐hairpin that are not found in other RNase H family proteins. The model with DNA suggests that the β‐hairpin partly blocks the active site, and in vivo activity assays show that the nuclease domain is not functional in the absence of the ATPase domain. Here, we propose that the nuclease activity is regulated by movement of the β‐hairpin, altering active site access and the orientation of catalytically essential residues.
Plexin‐B1 is a GTPase activating protein for M‐Ras, remodelling dendrite morphology
Authors: Saito Yasuhiro , Oinuma Izumi , Fujimoto Satoshi , Negishi Manabu
Published: May 2009

Plexins are receptors for axonal guidance molecules known as semaphorins. We recently reported that the semaphorin 4D (Sema4D) receptor, Plexin‐B1, induces axonal growth cone collapse by functioning as an R‐Ras GTPase activating protein (GAP). Here, we report that Plexin‐B1 shows GAP activity for M‐Ras, another member of the Ras family of GTPases. In cortical neurons, the expression of M‐Ras was upregulated during dendritic development. Knockdown of endogenous M‐Ras—but not R‐Ras—reduced dendritic outgrowth and branching, whereas overexpression of constitutively active M‐Ras, M‐Ras(Q71L), enhanced dendritic outgrowth and branching. Sema4D suppressed M‐Ras activity and reduced dendritic outgrowth and branching, but this reduction was blocked by M‐Ras(Q71L). M‐Ras(Q71L) stimulated extracellular signal‐regulated kinase (ERK) activation, inducing dendrite growth, whereas Sema4D suppressed ERK activity and down‐regulation of ERK was required for a Sema4D‐induced reduction of dendrite growth. Thus, we conclude that Plexin‐B1 is a dual functional GAP for R‐Ras and M‐Ras, remodelling axon and dendrite morphology, respectively.