The aim of this study was to investigate the relationship between dog and cat ownership and gastroenteritis in young children. A diary study of 965 children aged 4–6 years living in rural or semi-rural South Australia was undertaken. Data were collected on pet ownership, drinking water and other risk factors for gastroenteritis. Overall 89% of households had pets and dog ownership was more common than cat ownership. The multivariable models for gastroenteritis and pet ownership indicated that living in a household with a dog or cat was associated with a reduced risk of gastroenteritis (adj. OR 0·71, 95% CI 0·55–0·92; OR 0·70, % CI 0·51–0·97 respectively). This paper adds to the evidence that pets are not a major source of gastroenteritis in the home and lends support to the health benefits of pet ownership. However, this must be weighed against the potential negative consequences, such as dog bites, particularly for this age group.

More people with hepatitis C virus pass through incarcerated settings each year than any other venue. The goal of this study was to assess inmates' attitudes towards hepatitis C testing and treatment while incarcerated. We interviewed 153 male and female inmates at the Rhode Island Department of Corrections (RIDOC). Ninety-one per cent of inmates said they would agree to be tested for hepatitis C and 95% said that they would be willing to be treated for hepatitis C while incarcerated. Thirty-three per cent perceived themselves to be at risk for hepatitis C. Inmates were very interested in hepatitis C testing and, if indicated treatment. Inmates' attitudes towards hepatitis C testing and treatment do not pose a major obstacle to implementing comprehensive hepatitis C screening and treatment programme in correctional settings.

The rate at which infectious diseases spread through farm animal populations depends both on individual disease characteristics and the opportunity for transmission via close contact. Data on the relationships affecting the contact structure of farm animal populations are, therefore, required to improve mathematical models for the spatial spread of farm animal diseases. This paper presents data on the contact network for agricultural shows in Great Britain, whereby a link between two shows occurs if they share common competitors in the sheep class. Using the network, the potential for disease spread through agricultural shows is investigated varying both the initial show infected and the infectious period of the disease. The analysis reveals a highly connected network such that diseases introduced early in the show season could present a risk to sheep at the majority of subsequent shows. This data emphasizes the importance of maintaining rigorous showground and farm-level bio-security.

The objectives of this study were to characterize faeco-orally transmitted parasitic diseases and to identify the factors associated with these diseases, with emphasis on environmental factors, in children ranging from 1 up to 5 years old residing in substandard settlement areas. A population-based cross-sectional epidemiological design was used in a non-random selection of 29 out of the 78 substandard settlement areas in the municipality of Juiz de Fora, Brazil. A sample of 753 children were assessed from the target population consisting of all children of the appropriate age range residing in the selected areas. Data were collected by means of domiciliary interviews with their mothers or with the person responsible for them. The Hoffmann–Pons–Janer method was used in the parasitological examination of faeces. Binary logistic regression models were used to identify the factors associated with the diseases. A total of 319 sample children presented faeco-orally transmitted parasitic diseases. The factors associated with these parasitic diseases included the children's age, family income, number of dwellers in the domicile, consumption of water from shallow wells, consumption of water from natural sources, absence of covered domiciliary water reservoirs, and the presence of sewage flowing in the street.

We obtained a list of all reported cases of Escherichia coli O157 in Alberta during the 2000–2002 period, and using scan statistics we identified yearly temporal and spatial clusters of reported cases of E. coli O157 during the summer and in southern Alberta. However, the location of the spatial cluster in the south was variable among years. The impact of using both outbreak and sporadic data or only sporadic data on the identification of spatial and temporal clusters was small when analysing individual years, but the difference between spatial clusters was pronounced when scanning the entire study period. We also identified space-time clusters that incorporated known outbreaks, and clusters that were suggestive of undetected outbreaks that we attempted to validate with molecular data. Our results suggest that scan statistics, based on a space-time permutation model, may have a role in outbreak investigation and surveillance programmes by identifying previously undetected outbreaks.

This study analyses a screening programme for hepatitis C virus (HCV) infection among US veterans in a suburban Veterans Affairs Medical Center, in New York. This is the first study examining all 11 potential risk factors listed in the 2001 National U.S. Veterans Health Administration Screening Guidelines. A retrospective study was conducted of 5400 veterans ‘at risk’ of HCV, identified through a questionnaire in this institution's primary-care outpatient departments between 1 October 2001 and 31 December 2003. Multivariate logistic regression models were built to identify independent predictors of infection. Of 2282 veterans tested for HCV, 4·6% were confirmed by HCV PCR to be HCV infected. In the multivariate model developed, injection drug use, blood transfusion before 1992, service during the Vietnam era, tattoo, and a history of abnormal liver function tests were independent predictors of HCV infection. Our data support considering a more targeted screening approach that includes five of the 11 risk factors.

Large outbreaks of giardiasis caused by person-to-person transmission, or a combination of transmission routes, have not previously been reported. A large, prolonged giardiasis outbreak affected families belonging to a country club in a suburb of Boston, Massachusetts, during June–December 2003. We conducted a retrospective cohort study to determine the source of this outbreak. Giardiasis-compatible illness was experienced by 149 (25%) respondents to a questionnaire, and was laboratory confirmed in 97 (65%) of these cases. Of the 30 primary cases, exposure to the children's pool at the country club was significantly associated with illness (risk ratio 3·3, 95% confidence interval 1·7–6·5). In addition, 105 secondary cases probably resulted from person-to-person spread; 14 cases did not report an onset date. This outbreak illustrates the potential for Giardia to spread through multiple modes of transmission, with a common-source outbreak caused by exposure to a contaminated water source resulting in subsequent prolonged propagation through person-to-person transmission in the community. This capacity for a common-source outbreak to continue propagation through secondary person-to-person spread has been reported with Shigella and Cryptosporidium and may also be a feature of other enteric pathogens having low infectious doses.

The records of sewer baiting work for three London boroughs were examined to see whether there were locations that exhibited ‘rat’ (Rattus norvegicus) activity more often than would be expected by chance, a feature we dubbed ‘hotspots’. More than 100 000 baiting records were checked covering 15 years of the London Borough of Enfield (Enfield) and 5 years each of the London Borough of Barnet (Barnet), and the Royal Borough of Kensington and Chelsea (RBKC). The additional boroughs were included for comparison to see whether any effect observed was confined to Enfield or was a feature that could be found in both inner and outer city locations. Each borough was divided into kilometre squares corresponding with those found both on Ordnance Survey maps and also Thames Water Utilities Asset maps. The number of records per square were logged and then the number of positive records for all the manholes in that square on a year-on-year basis. We examined 350 km2 in Enfield, 377 km2 in Barnet and 66 km2 in RBKC. The data were subjected to a weighted analysis (i.e. allowing for the number of manholes per square and the varying total rat population from year to year). Some areas were shown to exhibit significantly higher amounts of activity than others suggesting that their distribution is not random and that there must be environmental and other factors, which make certain locations attractive to rats. Squares with very high activity, repeating year-on-year, ‘hotspots’, were found in all three boroughs, suggesting that the phenomena are widespread.

A case-control study was undertaken in an acute district general hospital to identify risk factors for hospital-acquired bacteraemia caused by methicillin-resistant Staphylococcus aureus (MRSA). Cases of hospital-acquired MRSA bacteraemia were defined as consecutive patients from whom MRSA was isolated from a blood sample taken on the third or subsequent day after admission. Controls were randomly selected from patients admitted to the hospital over the same time period with a length of stay of more than 2 days who did not have bacteraemia. Data on 42 of the 46 cases of hospital-acquired bacteraemia and 90 of the 92 controls were available for analysis. There were no significant differences in the age or sex of cases and controls. After adjusting for confounding factors, insertion of a central line [adjusted odds ratio (aOR) 35·3, 95% confidence interval (CI) 3·8–325·5] or urinary catheter (aOR 37·1, 95% CI 7·1–193·2) during the admission, and surgical site infection (aOR 4·3, 95% CI 1·2–14·6) all remained independent risk factors for MRSA bacteraemia. The adjusted population attributable fraction, showed that 51% of hospital-acquired MRSA bacteraemia cases were attributable to a urinary catheter, 39% to a central line, and 16% to a surgical site infection. In the United Kingdom, measures to reduce the incidence of hospital-acquired MRSA bacteraemia in acute general hospitals should focus on improving infection control procedures for the insertion and, most importantly, care of central lines and urinary catheters.

The aim of this study was to describe the natural history of HCV after 16 years of infection, in a cohort of individuals who acquired their infections on a known date in the United Kingdom. A total of 924 HCV-infected transfusion recipients (cases) and 475 anti-HCV negative transfusion recipients (controls) were eligible for inclusion in the study. Survival was compared between cases and controls to see if there was any excess mortality attributable to HCV. The results show that all-cause mortality was not significantly different between cases and controls (hazard ratio 1·17, 95% CI 0·92–1·49, P=0·21). However, the risk of death directly from liver disease was higher in cases than controls (hazard ratio 2·71, 95% CI 1·09–6·75, P=0·03). Nearly 30% of those HCV-infected cases who died directly from liver disease were known to have consumed excess alcohol.

Hepatitis C virus (HCV) and hepatitis B virus (HBV) are highly prevalent, often co-occuring infections among drug users. We examined HBV prevalence and risk behaviour patterns among a group of HCV-negative heroin and/or cocaine users in order to understand HBV risk and prevention opportunities among this unique group. Of 164 people enrolled, 44% had injected drugs. Overall, 24% of participants tested positive for exposure to HBV; drug injectors (28%) were only slightly and not significantly (P=0·287) more likely to test positive than those who had never injected drugs (21%). HBV exposure was significantly associated with multiple indicators of greater sex risk. HBV status was not associated with any demographic characteristic, but participants who reported longer duration of cocaine use were significantly less likely to test positive to exposure for HBV. It appears that HBV risk among HCV-negative drug users in this cohort is primarily due to sexual behaviour.

Mycobacterium avium subspecies paratuberculosis (Map), the cause of ruminant paratuberculosis, has been proposed as the causative agent of Crohn's disease. The objective of this study was to determine whether exposure to clinical cases of bovine paratuberculosis was a risk factor for Crohn's disease. A questionnaire was sent to dairy farmers living on premises where the occurrence or absence of clinical cases of bovine paratuberculosis had previously been determined. The prevalence of Crohn's disease was found to be similar to that reported in other studies in the United Kingdom and showed no association with bovine paratuberculosis. There was, however, a univariate association with geographical region. Ulcerative colitis showed univariate associations with age, frequency of contact with cattle and with smoking. The results do not support the hypothesis that Map plays a causative role in the aetiology of Crohn's disease.

Over the past years Shiga-like toxin-producing Escherichia coli (STEC) O157:H7 emerged as an important cause of severe gastrointestinal illnesses and haemolytic–uraemic syndrome (HUS) with up to 10% of children infected with STEC developing HUS. We conducted a geographical ecological study using the district as the statistical unit. For each district, we estimated the incidence of HUS among children <15 years for the period 1996–2001 from national HUS surveillance data and data obtained on cattle density. We used multivariate Poisson regression to quantify the relation, adjusted for covariates, between paediatric HUS incidence and exposure to cattle. In univariate analysis, a positive association was observed between several cattle-density indicators and HUS incidence. In multivariate analysis, HUS paediatric incidence was associated with dairy cattle density and the ratio of calves to children <15 years (P<0·001). Our findings are consistent with previous studies in other countries and support the recommendation to limit exposure of children to dairy cattle and manure to reduce the risk of STEC infection.

In April 2002, five cases of fascioliasis were diagnosed in Tourcoing. A case-finding and a case-control study were carried out to identify the source of the outbreak and take appropriate control measures. Eighteen cases were identified through the medical laboratories carrying out serology for fascioliasis. Fourteen cases and 23 controls, identified by the physicians of the cases, were interviewed on symptoms of the disease and their consumption of uncooked plants. Cases were more likely than controls to have eaten commercialized raw watercress (OR 86·7, P<0·001) and 13 (93%) of the cases reported its consumption. A single producer common to all cases was identified. The inspection of his watercress beds showed a lack of protection against Lymnaea truncatula. This outbreak of fascioliasis due to commercialized watercress indicates that actual sanitary regulations do not allow for the efficient prevention of infestation of watercress production in France.

In February and in June 1998, two people developed acute hepatitis B following in-patient care in a district general hospital. Initial enquiries indicated their infections were not attributable to staff undertaking exposure-prone procedures (EPPs). We report the findings and implications of the subsequent investigation: a multi-disciplinary, multi-agency investigation, including molecular epidemiological analysis. Occupational Health records showed that staff involved in EPPs with the patients were HBsAg negative. No contact between the patients was identified nor were there failures in sterilization. The patients' HBV strains were identical, indicating a common source. A total of 231 out of 232 staff who might have treated either patient were tested for HBsAg; the remaining doctor, working abroad, was HBsAg- and HBeAg-positive and had the same HBV strain as the patients. On two occasions the doctor's hand had been cut while breaking glass vials, but there was no documentation linking these events to the two patients. The doctor had been vaccinated in 1993 and tested for anti-HBs prior to commencing work in 1997. The doctor was recalled to Occupational Health but did not attend and was not followed up. In total, 4948 patients potentially treated by the doctor received an explanatory letter and 3150 were tested for HBsAg. Only one was positive, and HBV sequencing showed no link to the doctor. Occasionally transmission of HBV from heath-care workers can occur in a non-EPP setting and the implications of this require examination by those setting national policy. Occupational Health Services should investigate clinical heath-care workers who do not respond to vaccination. They should ensure HBV carriers are identified and offer them appropriate advice to prevent transmission to patients.

Co-circulation of respiratory syncytial virus (RSV) and influenza has made the partitioning of morbidity and mortality from each virus difficult. Given the interaction between chronic obstructive lung disease (COPD) and pneumonia, often one can be mistaken for the other. Multivariate time-series methodology was applied to examine the impact of RSV and influenza on hospital admissions for bronchiolitis, pneumonia, and COPD. The Granger Causality Test, used to determine the causal relationship among series, showed that COPD and pneumonia are not influenced by RSV (P=0·2999 and 0·7725), but RSV does influence bronchiolitis (P=0·0001). Influenza was found to influence COPD, pneumonia, and bronchiolitis (P<0·0001). The use of multivariate time series and Granger causality applied to epidemiological data clearly illustrates the significant contribution of influenza and RSV to morbidity in the population.

Stringency of milk pasteurization has been established on requirements for Coxiella burnetii as being the most heat-resistant organisms of public heath significance. This paper discusses the estimation of the efficiency of pasteurization time/temperature combinations as required in regulations for food safety. Epidemiological studies have been interpreted as C. burnetii being a significant pathogen causing clinical disease through ingestion of milk. The paper examines the evidence and challenges the designation of C. burnetii as a foodborne pathogen. Consequently it questions the need for pasteurization parameters to be established on its heat resistance characteristics.

Twenty-one Candida albicans isolates from three HIV-infected patients were collected over a period of 3 years and characterized for fluconazole susceptibility, infectivity and genetic relatedness. Fluconazole resistance was found in five isolates, four exhibited dose-dependent susceptibility and the remainder were fully susceptible to this agent. Pulsed-field gel electrophoresis of SfiI restriction digests of the genomic DNA from the isolates revealed that isolates from the same swab specimen were identical despite differences in susceptibility to fluconazole and isolates recovered over time from the three patients retained clonally related DNA fingerprints within each patient. This small-scale study confirms the persistence of oral colonization of C. albicans strains in HIV-infected patients. Clinical data also suggests that the primary infecting strain may become a persistent colonist in the oral cavity once the immune function of the patient has been restored.

Nasopharyngeal carriage of potential pathogens was studied in 425 healthy 3- to 6-year-old children attending 16 day-care centres (DCCs) in nine Czech cities during the winter 2004–2005. The overall carriage of pathogens was 62·8% (Streptococcus pneumoniae, 38·1%; Haemophilus influenzae, 24·9%; Moraxella catarrhalis, 22·1%; Staphylococcus aureus, 16%). An age-related downward trend was observed for colonization with respiratory pathogens in contrast to Staph. aureus whose carriage was significantly higher among older children. The following serotypes of colonizing S. pneumoniae were the most predominant: 23F (20·6%), 6A (15·1%), 6B (12·7%), 18C (7·8%), 15B and 19F (6% each). The majority (94·3%) of H. influenzae isolates were non-typable; among capsulated isolates, serotype b was not found. Decreased susceptibility to penicillin was determined in 3% of pneumococci; 4·6% of H. influenzae strains and 85·1% of M. catarrhalis strains produced β-lactamase. As for non-β-lactam antibiotics, pneumococci resistant to trimethoprim–sulphamethoxazole were the most common (15·7%) among the attendees.

This study investigates a sorbitol-fermenting enterohaemorrhagic Escherichia coli (SF EHEC) O157 infection in a farmer's family in the Austrian province of Salzburg. The investigation commenced after a 10-month-old boy was admitted to hospital with the clinical diagnosis of a haemolytic–uraemic syndrome (HUS) and his stool specimen grew SF EHEC O157:H−. In a subsequent environmental survey, a stool specimen of the 2-year-old brother and faecal samples of two cattle from the family's farm were also found to be positive for SF EHEC O157:H−. All four isolates had indistinguishable phenotypic and molecular characteristics and were identical to the first strain detected in Bavaria in 1988. Despite identical isolates being demonstrated in Bavaria after 1988, and until this report, increased surveillance in neighbouring Austria had not found this organism. We propose that the strain may have recently spread from Bavaria to Austria. Although SF EHEC O157:H− strains are still rare, they may represent a considerable health threat as they can spread from farm animals to humans and between humans.