National outbreak of Salmonella Ajiobo infection in England and Wales, June 2006.
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Journal Article↗
Biomedical subjects
G K Adak
Publications and source records attributed to G K Adak.
Outbreaks of waterborne infectious intestinal disease in England and Wales, 1992-2003.
We reviewed the epidemiological and microbiological characteristics of 89 reported outbreaks of waterborne infectious intestinal disease affecting 4321 people in England and Wales over the period 1992-2003. Public water supplies were implicated in 24 outbreaks (27%), private water supplies in 25 (28%), swimming pools in 35 (39%) and other sources in five outbreaks (6%). Cryptosporidium was implicated in 69% of outbreaks, Campylobacter sp. in 14%, Giardia in 2%, E. coli O157 in 3% and Astrovirus in 1%. From 2000, there was a consistent decline in the number of outbreaks of waterborne disease associated with public water supplies. The incidence rate of outbreaks in recipients of private water supplies may be as high as 35 times the rate in those receiving public water supplies (1830 vs. 53 per million population). Private water suppliers need to be aware of the importance of adequate treatment and the prevention of faecal contamination of storage water. Swimming-pool operators need to ensure chlorination and in particular adequate filtration measures are in place.
Communicable Diseases↗
Publication bias in foodborne outbreaks of infectious intestinal disease and its implications for evidence-based food policy. England and Wales 1992-2003.
Systematic national surveillance of outbreaks of infectious intestinal disease (IID) was introduced in England and Wales in 1992 to provide comprehensive information on causative organisms, sources or vehicles of infection and modes of transmission. We compared information from this system with that published in the peer-reviewed literature between 1 January 1992 and 31 January 2003 to assess the potential effect of publication bias on food-safety policy. During the study period 1763 foodborne outbreaks of IID were reported to national surveillance. Fifty-five were published in the peer-reviewed literature. The peer-reviewed literature overestimated the impacts of milk/milk products, miscellaneous foods (e.g. sandwiches) and desserts and underestimated those of poultry, fish and shellfish, red meat/meat products and eggs/egg products. Without systematic surveillance, knowledge of causative organisms, sources or vehicles of infection and modes of transmission, as gleaned from the peer-reviewed literature, would potentially distort food-safety policy.
Animals↗
Foodborne general outbreaks of Salmonella Enteritidis phage type 4 infection, England and Wales, 1992-2002: where are the risks?
Foodborne outbreaks of Salmonella enterica serovar Enteritidis phage type 4 (PT4) infection (n=497), reported to the Health Protection Agency Communicable Disease Surveillance Centre between 1992 and 2002, were compared with other pathogens (n=1148) to determine factors (season, setting, food vehicles, food safety faults) associated with this pathogen. Logistic regression was applied to control for potential confounding. Foodborne general outbreaks of S. Enteritidis PT4 infection were more likely to occur in the spring and summer, and were more often linked to schools, private residences and residential institutions. Eggs, egg products and the use of raw shell egg were strongly associated with this pathogen. Most outbreaks were linked to cross-contamination and inadequate heat treatment. This paper describes the decline in the S. Enteritidis PT4 epidemic, providing evidence that control measures introduced, e.g. improved biosecurity and vaccination, have worked. Continued surveillance of human and veterinary salmonellosis is essential to detect future problems.
Disease Outbreaks↗
Foodborne general outbreaks of Shiga toxin-producing Escherichia coli O157 in England and Wales 1992-2002: where are the risks?
Between 1 January 1992 and 31 December 2002, Shiga toxin-producing Escherichia coli O157 (STEC O157) accounted for 44 of the 1645 foodborne general outbreaks of infectious intestinal disease reported to the Health Protection Agency Communicable Disease Surveillance Centre. These outbreaks, although rare, were characterized by severe infection, with 169 hospital admissions and five deaths reported. STEC O157 outbreaks were compared with other pathogens to identify factors associated with this pathogen. Single risk variable analysis and logistic regression were employed. Two distinct aetiologies were identified. Foodborne outbreaks of STEC O157 infection in England and Wales were independently associated with farms, which related to milk and milk products, and with red meats/meat products, which highlighted butchers' shops as a cause for concern. The introduction and adherence to effective control measures, based on the principles of hazard analysis, provide the best means of minimizing the risk of foodborne infection with this pathogen.
Disease Outbreaks↗
Campylobacter coli - an important foodborne pathogen.
OBJECTIVES: Campylobacters are the most common bacterial cause of infectious intestinal disease (IID) in temperate countries. C. jejuni is the predominant cause of campylobacter IID, but the impact of other, less prevalent species has largely been ignored. Here, we present estimates of the burden of indigenously acquired foodborne disease (IFD) due to Campylobacter coli, the second most common cause of human campylobacteriosis. METHODS: Data from surveillance sources and specific epidemiologic studies were used to calculate the number of illnesses, presentations to general practice (GP), hospital admissions, hospital occupancy and deaths due to indigenous foodborne C. coli IID in England and Wales for the year 2000. RESULTS: We estimate that in the year 2000, C. coli accounted for over 25,000 cases of IFD. This organism was responsible for more than 12,000 presentations to GP, 1000 hospital admissions, nearly 4000 bed days of hospital occupancy and 11 deaths. The cost to patients and the National Health Service was estimated at nearly pound 4 million. CONCLUSIONS: Although C. coli comprises a minority of human campylobacter disease, its health burden is considerable and greater than previously thought. Targeted research on this organism is required for its successful control.
Campylobacter Infections↗
A national outbreak of multi-resistant Salmonella enterica serovar Typhimurium definitive phage type (DT) 104 associated with consumption of lettuce.
Between 1 August and 15 September 2000, 361 cases of Salmonella enterica serotype Typhimurium definitive phage type (DT) 104, resistant to ampicillin, chloramphenicol, streptomycin, sulphonamides, spectinomycin and tetracycline (R-type ACSSuSpT), were identified in England and Wales residents. Molecular typing of 258 isolates of S. Typhimurium DT104 R-type ACSSuSpT showed that, although isolates were indistinguishable by pulsed-field gel electrophoresis, 67% (174/258) were characterized by a particular plasmid profile. A statistically significant association between illness and consumption of lettuce away from home was demonstrated (OR = 7.28; 95% CI=2.25-23.57; P=0.0006) in an unmatched case-control study. Environmental investigations revealed that a number of food outlets implicated in the outbreak had common suppliers of salad vegetables. No implicated foods were available for microbiological testing. An environmental audit of three farms that might have supplied salad vegetables to the implicated outlets did not reveal any unsafe agricultural practices. The complexity of the food supply chain and the lack of identifying markers on salad stuffs made tracking salad vegetables back to their origin extremely difficult in most instances. This has implications for public health since food hazard warnings and product withdrawal are contingent on accurate identification of the suspect product.
Bacteriophage Typing↗
General outbreaks of infectious intestinal disease (IID) in hospitals, England and Wales, 1992-2000.
Between 1992 and 2000, 26.6% (1,396/5,257) of all general outbreaks of infectious intestinal disease (IID) reported to the Public Health Laboratory Service (PHLS) Communicable Disease Surveillance Centre (CDSC) occurred in hospitals. Over 29,000 patients and staff were affected and the mortality risk was higher than for outbreaks in other settings [relative risk 2.00 (95% CI: 1.52-2.63) P<0.001]. Person-to-person spread was the predominant mode of transmission. The mortality risk was highest in foodborne disease outbreaks [relative risk 3.22 (95% CI: 1.41-7.36); P=0.003]. Most outbreaks occurred between November and April. The pathogens most frequently reported were Norwalk-like virus (NLV) (54%) and Clostridium difficile (12.6%). These findings emphasize the public health importance of outbreaks of IID in hospitals, especially during the winter when pressures on hospitals are at their height.
Caliciviridae Infections↗
Investigation of an outbreak of E. coli O157 infections associated with a trip to France of schoolchildren from Somerset, England.
A retrospective cohort study was conducted after 2 confirmed and 8 probable cases of VTEC 0157 occurred in a schoolgroup from Somerset following a trip to France. The strain of the 2 confirmed cases was vero-cytotoxin type 2, phage type 34. Despite its low statistical power due to small numbers, this study suggested the most likely vehicle of infection was cucumber salad (crude RR=4.3, 95%CI [0.6-29], adjusted OR=107, 95%CI indeterminate, p=0.08). The cucumbers were purchased from Belgium but it was not possible to trace them back to source. The international nature of this outbreak emphasises the importance of close collaboration between organisations in the management of outbreaks, of ensuring international standards in food safety, and of agreeing a common standard in VTEC typing across Europe.
Adolescent↗
Point source outbreaks of Campylobacter jejuni infection--are they more common than we think and what might cause them?
Despite being the commonest bacterial cause of infectious intestinal disease (IID) in England and Wales, outbreaks of campylobacter infection are rarely reported. However, data from the Campylobacter Sentinel Surveillance Scheme suggested that outbreaks might be more common than was previously suspected, since a high proportion of cases reported other illness in the home or in the community at the same time as their illness. To identify factors that might lead to these apparent outbreaks, the exposures of cases of Campylobacter jejuni infection reporting other illness, either in the home or the community, were compared with those for cases not reporting other illness using case-case methodology. Illness in the home was associated with consuming organic meats in the winter, having contact with a pet suffering from diarrhoea or visiting a farm in the 2 weeks before the onset of symptoms. Illness in the community was associated with the consumption of foods in restaurants or drinking unpasteurized milk. Prevention of campylobacter infection requires that better methods of outbreak detection and investigation are developed, which in turn should lead to a better understanding of risk factors.
Adolescent↗
Milkborne general outbreaks of infectious intestinal disease, England and Wales, 1992-2000.
From 1 January 1992 to 31 December 2000, 27 milkborne general outbreaks of infectious intestinal disease (IID) were reported to the Public Health Laboratory Service (PHLS) Communicable Disease Surveillance Centre (CDSC). These outbreaks represented a fraction (2%) of all outbreaks of foodborne origin (N = 1774) reported to CDSC, but were characterized by significant morbidity. Unpasteurized milk (52%) was the most commonly reported vehicle of infection in milkborne outbreaks, with milk sold as pasteurized accounting for the majority of the rest (37%). Salmonellas (37%), Vero cytotoxin-producing Escherichia coli (VTEC) O157 (33%) and campylobacters (26%) were the most commonly detected pathogens, and most outbreaks were linked to farms (67%). This report highlights the importance of VTEC O157 as a milkborne pathogen and the continued role of unpasteurized milk in human disease.
Animals↗
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.
Communicable Diseases↗
Trends in indigenous foodborne disease and deaths, England and Wales: 1992 to 2000.
BACKGROUND: Commitment to food safety is evidenced by high profile governmental initiatives around the globe. To measure progress towards targets, policy makers need to know the baseline from which they started. AIM: To describe the burden (mortality, morbidity, new presentations to general practice, hospital admissions, and hospital occupancy) and trends of indigenous foodborne disease (IFD) in England and Wales between 1992 and 2000. METHODS: Routinely available surveillance data, special survey data, and hospital episode statistics were collated and arithmetic employed to estimate the burden and trends of IFD in England and Wales. Adjustments were made for underascertainment of disease through national surveillance and for foreign travel. The final estimates were compared with those from the USA. RESULTS: In 1995 there were an estimated 2,365,909 cases, 21,138 hospital admissions, and 718 deaths in England and Wales due to IFD. By 2000 this had fallen to 1,338,772 cases, 20,759 hospital admissions, and 480 deaths. In terms of disease burden the most important pathogens were campylobacters, salmonellas, Clostridium perfringens, verocytotoxin producing Escherichia coli (VTEC) O157, and Listeria monocytogenes. The ratio of food related illness in the USA to IFD in England and Wales in 2000 was 57:1. Taking into account population rates, this ratio fell to 11:1 and converged when aetiology and disease severity were considered. CONCLUSION: Reducing IFD in England and Wales means tackling campylobacter. Lowering mortality rates however also requires better control and prevention of salmonellas, Cl perfringens, L monocytogenes, and VTEC O157.
Campylobacter Infections↗
General outbreaks of infectious intestinal disease linked with salad vegetables and fruit, England and Wales, 1992-2000.
Between 1992 and 2000, 1,518 foodborne general outbreaks of infectious intestinal disease (IID) were reported to the Public Health Laboratory Service (PHLS) Communicable Disease Surveillance Centre (CDSC), of which 83 (5.5%) were associated with the consumption of salad vegetables or fruit (SVF). The pathogens most frequently reported were salmonellas (41.0%) and Norwalk-like virus (NLV) (15.7%). In total 3,438 people were affected; 69 were admitted to hospital and one person died. Most outbreaks were linked to commercial catering premises (67.5%). Three community outbreaks, of Salmonella enterica serovar Typhimurium Definitive Phage Type (DT) 104, S. Typhimurium DT 204b and Shigella sonnei infection, were found to be associated with lettuce contaminated at source, and these accounted for 501 (14.6%) cases. The latter two outbreaks were international, involving several European countries. This demonstrates how contamination of SVF during production/processing can result in major, geographically widespread, outbreaks of infection with serious public health consequences.
Disease Outbreaks↗
General outbreaks of infectious intestinal diseases linked with private residences in England and Wales, 1992-9: questionnaire study.
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Community-Acquired Infections↗
Verocytotoxin-producing Escherichia coli (VTEC) O157 and other VTEC from human infections in England and Wales: 1995-1998.
A total of 3429 isolations of verocytotoxin-producing Escherichia coli O157 (VTEC O157) was confirmed from human sources in England and Wales during the period 1995-1998. The largest annual total was 1087 in 1997. Most infections occurred in the third quarter of each year. The overall rate of infection ranged from 1.28 to 2.10/100,000 population and showed regional variation. The highest incidence was in children aged 1-4 years. Annually, between 5% and 11% of strains were from patients who had travelled abroad. There were 67 general outbreaks of infection represented by 407 (11.9%) VTEC O157 isolates. Outbreaks involved transmission by contaminated food or water, person-to-person spread and direct or indirect animal contact, and five were associated with foreign travel. The majority (76%) of strains carried verocytotoxin (VT) 2 genes and 23.3% were VT1+VT2. Most strains had the flagellar antigen H7, but c. 14% were non-motile. Approximately 20% of isolates were resistant to antimicrobial agents, predominantly streptomycin, sulphonamides and tetracycline. In addition to VTEC O157, strains of serogroup O157 that did not possess VT genes were identified. These were either derivatives of VTEC O157 that had lost VT genes or were strains with H antigens other than H7 that have never been associated with VT production. Strains of VTEC other than O157 were characterised. Most were associated with diarrhoea, bloody diarrhoea or haemolytic uraemic syndrome and had virulence markers in addition to VT.
Adolescent↗
General outbreaks of infectious intestinal disease associated with fish and shellfish, England and Wales, 1992-1999.
Between 1992 and 1999 1425 foodborne general outbreaks of Infectious Intestinal Disease (IID) were reported to the PHLS Communicable Disease Surveillance Centre. Of these, 148 (10%) were associated with the consumption of fish and shellfish. Three main aetiologies were identified. Outbreaks associated with fish (47%) occurred more frequently in the summer months, and were linked with Scombrotoxic fish poisoning caused by the consumption of tuna that was improperly stored. Outbreaks associated with molluscs (36%) were associated with the consumption of oysters contaminated with viral pathogens, particularly in February. Outbreaks associated with the consumption of crustaceans (11%) often involved eating prawns that contained either salmonellas or viral pathogens. The maintenance of microbial quality from prior to capture/harvesting until the moment of consumption, based on a Hazard Analysis and Critical Control Point style approach, is essential if gastrointestinal illness associated with such produce is to be avoided.
Adolescent↗
The Task Force on E. coli O157 Final Report: the view from here.
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Advisory Committees↗