bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

SummaryThe 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

SummaryThe 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

SummaryData 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

SummaryThe 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

SummaryIn 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

SummaryThe 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

SummaryIn 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

SummaryMathematical 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

SummaryIn 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

SummaryBetween 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

SummaryAn 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

SummaryIn 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

SummaryTraditionally 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

SummaryComplex 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

SummaryOne 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

SummaryUsing 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

SummaryDuring 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

SummaryRoe 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

SUMMARYClinical 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).