An outbreak of food-borne botulism in Scotland, United Kingdom, November 2011.

An investigation is currently underway to explain an outbreak of food-borne botulism in Scotland. Three children in the same family were confirmed as having botulism following consumption of a meal made with a jar of korma sauce. Residual sauce from the jar, the jar lid and a remnant of the meal, all tested positive for Clostridium botulinum type A toxin. The children are recovering, although two remain ventilated and in intensive care unit.

Temperature-dependent transmission of rotavirus in Great Britain and The Netherlands.

In Europe, rotavirus gastroenteritis peaks in late winter or early spring suggesting a role for weather factors in transmission of the virus. In this study, multivariate regression models adapted for time-series data were used to investigate effects of temperature, humidity and rainfall on reported rotavirus infections and the infection-rate parameter, a derived measure of infection transmission that takes into account population immunity, in England, Wales, Scotland and The Netherlands. Delayed effects of weather were investigated by introducing lagged weather terms into the model. Meta-regression was used to pool together country-specific estimates. There was a 13 per cent (95% confidence interval (CI), 11-15%) decrease in reported infections per 1 degrees C increase in temperature above a threshold of 5 degrees C and a 4 per cent (95% CI, 3-5%) decrease in the infection-rate parameter per 1 degrees C increase in temperature across the whole temperature range. The effect of temperature was immediate for the infection-rate parameter but delayed by up to four weeks for reported infections. There was no overall effect of humidity or rainfall. There is a direct and simple relationship between cold weather and rotavirus transmission in Great Britain and The Netherlands. The more complex and delayed temperature effect on disease incidence is likely to be mediated through the effects of weather on transmission.

Campylobacter immunity and coinfection following a large outbreak in a farming community.

An outbreak of campylobacteriosis affected approximately one-half of 165 people attending an annual farmers' dance in Montrose, Scotland, in November 2005. Epidemiological investigations, including a cohort study (n = 164), identified chicken liver paté as the most likely vehicle of infection. Paté preparation involved deliberate undercooking of chicken livers by flash-frying, followed by mechanical homogenization. Typing of 32 Campylobacter strains (isolated from submitted stools) by multilocus sequence typing identified four distinct clades of Campylobacter jejuni. There was good agreement when isolates were typed by Penner serotyping, pulsed-field gel electrophoresis, and flaA short variable region sequencing but poorer agreement with phage and antibiotic susceptibility testing. At least three attendees were coinfected with two Campylobacter strains each. The outbreak was probably due to several livers contributing Campylobacter strains that survived undercooking and were dispersed throughout the paté. The study highlights improper culinary procedures as a potential human health risk and provides a striking counterexample to the "dominant outbreak strain" view of point source outbreaks of food-borne infections. It also demonstrates that previous exposure to biologically plausible sources of Campylobacter may confer protection against subsequent infection.

Clinical management of children with suspected or confirmed E. coli O157 infection.

Scotland continues to report higher rates of infection with Escherichia coli O157 than elsewhere in the UK. Infection with E. coli O157 usually manifests as acute, afebrile, painful, bloody diarrhoea and is the commonest cause of Haemolytic Uraemic Syndrome (HUS), an important cause of childhood renal failure. In 1996 an outbreak of E. coli O157 infection in Central Scotland, resulted in over 500 cases and 17 deaths. Ten years on, high-profile outbreaks of E. coli O157 infection in Scotland still result in cases of HUS and fatalities. We sought to identify outcomes and describe pre-hospital clinical management strategies using prospective, national surveillance of paediatric HUS cases, from 2003 to 2006 inclusive. We recommend that children who present with acute, afebrile, and painful bloody diarrhoea be referred to hospital as early as possible for appropriate clinical management.

How protective is breast feeding against diarrhoeal disease in infants in 1990s England? A case-control study.

AIMS: To assess the effect of several measures of infant feeding on diarrhoeal disease, and whether these effects vary according to markers of social deprivation. METHODS: Case-control study of diarrhoeal disease cases presenting to 34 general practices in England. Controls were stratified on age group, area deprivation index for the practice, and whether or not the practice was in London. Data were available on 304 infants (167 cases and 137 controls). RESULTS: After adjustment for confounders, breast feeding was associated with significantly less diarrhoeal disease. Associations were striking even in infants aged > or = 6 months. They did not vary by social class, but were greater in those living in rented council accommodation and in more crowded households. The effect of receiving no breast milk was stronger in more deprived areas than in less deprived areas. The effect of not receiving exclusive breast milk was stronger in more deprived areas than in less deprived areas. In formula fed infants, there was significantly more diarrhoeal disease in those not sterilising bottles/teats with steam or chemicals. The protective effect of breast feeding did not persist beyond two months after breast feeding had stopped. CONCLUSIONS: Breast feeding protects against diarrhoeal disease in infants in England although the degree of protection may vary across infants and wear off after breast feeding cessation. Education about the benefits of breast feeding and the risks of inadequate sterilisation should be targeted at carers in deprived areas or households.

Epidemiology of Salmonella enterica serovars enteritidis and Typhimurium in animals and people in Scotland between 1990 and 2001.

Two serovars of salmonella which are currently of particular importance in both human and animal infections are Salmonella enterica serovars Enteritidis phage type 4 (PT4) and Typhimurium definitive type 104 (DT104). This paper describes the trends in the relationships between the levels of infection of people and a range of farm animal species with these two serovars and explores some of the reasons behind them. In 1996, there was a peak of 520 reports of S Typhimurium DT104 infection in people in Scotland, but the number has decreased every year since, to 96 in 2001. In cattle the incidence of S Typhimurium DT104 also peaked in 1996, with 138 incidents, and it has similarly decreased every year to 2001 when there were 10 reported incidents. Similar declines have been observed in its incidence in sheep and pigs. In people the number of reports of S Enteritidis PT4 peaked in 1997 at 1684 and then declined to 457 in 2001. In chickens, the number of reports of S Enteritidis PT4 peaked in 1998 at 34 incidents, but no incidents were reported in the following three years.

A European outbreak of Salmonella enterica serotype Typhimurium definitive phage type 204b in 2000.

OBJECTIVE: To describe the clinical, epidemiologic and microbiological features of a large outbreak of infection with a multiresistant Salmonella enterica serotype Typhimurium definitive type DT204b infection involving at least 392 people in five European countries. METHODS: Icelandic public-health doctors responded to a report on an Internet news site of an outbreak of infection with a multiresistant strain of Typhimurium DT104 in England by contacting the Public Health Laboratory Service (PHLS) Communicable Disease Surveillance Centre (CDSC). An international alert was sent out through Enter-net. All strains from England & Wales, The Netherlands, Scotland and Germany, and 17 of the outbreak isolates from Iceland, were phage-typed, screened for antimicrobial resistance, and subjected to molecular typing. Hypothesis-generating interviews were conducted, followed by case-control studies performed in Iceland and England. RESULTS: Isolates from cases in Iceland, England and Wales, The Netherlands, Scotland and Germany were identified as Typhimurium DT204b. The antimicrobial resistance pattern was ACGNeKSSuTTmNxCpL. All strains tested displayed an identical plasmid profile. Strains from five cases in England & Wales and five cases in Iceland possessed identical pulsed-field profiles. Although a common source was suspected, only Iceland implicated imported lettuce as a vehicle, with an analytic epidemiologic study (OR = 40.8; P = 0.005; 95% CI 2.7-3175). CONCLUSION: The identification of international outbreaks, necessary for investigation and control, can be facilitated by standardized phage-typing techniques, the electronic transfer of molecular typing patterns, formal and informal links established through international surveillance networks, and the early reporting of national outbreaks to such networks.

The infectious intestinal disease study of England: a prospective evaluation of symptoms and health care use after an acute episode.

The sequelae of Infectious Intestinal Disease (IID) in a population-based sample of cases and matched controls were investigated for a period of 3 months following the initial infection. Incident cases of IID presenting to GPs or occurring in the community and controls were studied at 3 weeks and over a 3-month follow-up period. Cases were six times more likely than controls to have gastrointestinal symptoms, particularly diarrhoea, at 3 weeks. Ten per cent of cases consulted their GP in the 3 months after episode and 2.3% were referred to hospital. GP presentation rates were twice as high in cases. Gastrointestinal symptoms persist after IID, leading to an increased likelihood of GP consultation and hospital referral. Diagnosis of irritable bowel syndrome may be more likely following IID. The burden of IID is likely to be considerable given its high incidence and the frequency of such sequelae.

Surveillance of foodborne outbreaks of infectious intestinal disease in England and Wales 1992-1999: contributing to evidence-based food policy?

Between 1992 and 1999, a total of 1426 general outbreaks of infectious intestinal disease reported to the Public Health Laboratory Service (PHLS) Communicable Disease Surveillance Centre (CDSC) were described as foodborne. Where the evidence base to support the conclusions drawn was provided (66.3% of outbreaks) a combination of microbiological and analytical evidence was reported in 4% of outbreaks (60/1426); microbiological evidence alone in 10% of outbreaks (149/1426); analytical evidence alone in 23% of outbreaks (322/1426); microbiological evidence in combination with descriptive epidemiology in 3% of outbreaks (46/1426) and descriptive epidemiology alone in 26% of outbreaks (365/1426). Information supplied to CDSC by local investigators appears to be of varying quality and depth and may be influenced by the individual characteristics of outbreaks such as size and duration, outbreak setting, causative organism, vehicles of infection and time of year. These findings have implications for the use of these surveillance data in developing evidence-based food policy.

Foodborne infectious risks: do we need a wide system of data collection and survey? The lessons learned from the study of infectious intestinal disease in England.

In 2000, the United Kingdom Government's Food Standards Agency published "A report of the study of infectious intestinal disease in England". This report was the result of over a decade's endeavour and cost well in excess of 2 million pound sterling (approximately 3.3 million euros). The study originated in 1989. In response to national epidemics of foodborne infection with Salmonella enteritidis phage type 4 and Listeria monocytogenes, the Government set up the Committee on the Microbiological Safety of Food (the Richmond Committee). This committee wished to know the actual level of clinical disease in the population giving rise to the laboratory reports of gastro-intestinal pathogens in national surveillance data and recommended studies to achieve this objective. In addition, successors to the to Richmond Committee decided that it would be of value to collect information from both cases and controls, including documenting exposure to biologically plausible risk factors so that differences between the ill and the well could be identified. Enquiries were also made about the clinical course of disease, so that long term sequelae and socio-economic costs could be estimated. A full description of this enormous study is beyond the scope of this paper, which defends the personal view that resources might have been better spent on a less ambitious enquiry.

The study of infectious intestinal disease in England: risk factors for cases of infectious intestinal disease with Campylobacter jejuni infection.

This is a case-control study aimed at identifying risk factors for intestinal infection with Campylobacter jejuni. Cases were defined as subjects with diarrhoea occurring in community cohorts or presenting to General Practitioners (GPs) with Campylobacter jejuni in stools. Controls were selected from GP lists or cohorts, matched by age, sex, and GP practice. Travel abroad and consumption of chicken in a restaurant were statistically significantly associated with being a case. There was no statistically significant risk associated with consumption of chicken other than in restaurants nor with reported domestic kitchen hygiene practices. Consumption of some foods was associated with a lower risk of being a case. Most cases remained unexplained. We suggest that infection with low numbers of micro-organisms, and individual susceptibility may play a greater role in the causation of campylobacter infection than previously thought. It is possible that in mild, sporadic cases infection may result from cross contamination from kitchen hygiene practices usually regarded as acceptable. Chicken may be a less important vehicle of infection for sporadic cases than for outbreaks, although its role as a source of infection in both settings requires further clarification in particular in relation to the effect of domestic hygiene practices. The potential effect of diet in reducing the risk of campylobacteriosis requires exploration.

Epidemiological investigation of the central Scotland outbreak of Escherichia coli O157 infection, November to December 1996.

On Friday, 22 November 1996, the microbiologist at a hospital in Lanarkshire, Scotland, identified presumptive Escherichia coli O157 in faecal specimens submitted by three patients with bloody diarrhoea, and confirmed its presence in one. Over the next 6 h, 12 more potential cases were identified. Investigations first indicated then confirmed a single food premises as the source of infection. Effective control measures were applied promptly. The outbreak was declared over on 20 January 1997, by which time 512 cases had been identified, and infection with the outbreak strain confirmed in 279. Twenty deaths occurred in cases during the outbreak and there were two more in cases during 1997. Seventeen of these deaths resulted from the outbreak. This paper describes the outbreak's epidemiological investigation, referring to other investigations, and control measures, where appropriate.

A study of infectious intestinal disease in England: risk factors associated with group A rotavirus in children.

OBJECTIVE: To identify risk factors for infectious intestinal disease (IID) due to rotavirus group A in children aged under 16 years. METHODS: Case-control study of cases of IID with rotavirus infection presenting to general practitioners (GPs) or occurring in community cohorts, and matched controls. RESULTS: There were 139 matched pairs. In children under 16 years the following risk factors were significantly associated with rotavirus IID: living in rented council housing (adjusted OR = 3.78, P = 0.022), accommodation with more than five rooms (OR = 0.72, P = 0.002), contact with someone ill with IID (OR = 3.45, P < 0.001). Some foods were associated with decreased risk. In infants, bottle feeding with or without breast feeding was associated with increased risk (OR = 9.06, P < 0.05). CONCLUSIONS: Contact with persons with IID, living in rented council housing and accommodation with fewer rooms, were significant risk factors for sporadic rotavirus IID in children whereas breast feeding is protective in infants.

Investigation and management of sporadic gastrointestinal infections with potentially Vero cytotoxin producing Escherichia coli in Scotland.

Recognition of the potential of Escherichia coli O157 and other Vero cytotoxin producing E. coli (VTEC) organisms to cause serious disease led to the recommendation that all diarrhoeal stool specimens be examined for E. coli O157. National guidelines exist for the testing and exclusion of cases and contacts of VTEC infection. A survey was conducted to discover the extent to which these recommendations are followed in Scotland by asking about current practices for public health management of identified cases and laboratory investigation of E. coli infection. About two thirds of Scottish health boards followed national guidelines for testing and exclusion of cases and contacts of VTEC O157 infection. Most laboratories tested all diarrhoeal stools for E. coli O157 but detection methods varied and a minority tested selected stools for non-O157 E. coli serogroups. Standardisation of policies for laboratory testing of VTEC infection would improve national surveillance. Adherence to evidence based guidelines would standardise public health management of VTEC infections in Scotland.

Food poisoning notification: time for a rethink.

The notification of food poisoning is a statutory obligation of medical practitioners in the United Kingdom. Its objectives and methods are vague and ill documented, and the value of its output doubtful. Statutory notification of food poisoning is poor at identifying outbreaks, or single cases of severe disease, or as a measure of longer term trends. It should be fundamentally reformed.

A study of infectious intestinal disease in England: plan and methods of data collection.

The Committee on the Microbiological Safety of Food, set up in 1989 by the Department of Health in response to national epidemics of foodborne infection, considered the available evidence and commissioned a study of infectious intestinal disease (IID) in England. Seventy practices (with 489,500) patients overall) recruited from the Medical Research Council's General Practice Research Framework between August 1993 and January 1995 collected data for one year. The practice populations were representative of practices in England by area and urban/rural location, but with fewer small and affluent practices. There were five main components. i) A population cohort of 9776 (40% of those eligible) were enrolled to estimate the incidence and aetiology of IID in the community, and a large proportion were followed up. A median of 10% of patients on practice age-sex registers had moved away or died. ii) A nested case control component based on cases ascertained in the cohort was used to identify risk factors for IID in the community. iii) In a case control component used to identify risk factors and to estimate the incidence and aetiology of IID presenting in 34 general practices 70% of the 4026 cases returned risk factor questionnaires, 75% submitted stools, and matched controls were found for 75% of cases. iv) An enumeration component was used to estimate the incidence of IID presenting to general practitioners (GPs) in 36 practices and the proportion of specimens sent routinely for microbiological examination. v) In a socioeconomic costs component used to estimate the burden of illness of IID in the community and presenting to GPs 63% of those who returned a risk factor questionnaire also returned a socioeconomic questionnaire and were representative by age, sex, and social class. Despite variable enrolment and compliance the study sample had sufficient power for the multivariable analysis. The characteristics associated with low enrollment and compliance must be considered in the interpretation of the main study results.