Report on verocytotoxin-producing Escherichia coli / Advisory Committee on the Microbiological Safety of Food.

  • Great Britain. Committee on the Microbiological Safety of Food. Working Group on Verocytotoxin-Producing Escherichia Coli.
Date:
1995
Catalogue details

Licence: Open Government Licence

Credit: Report on verocytotoxin-producing Escherichia coli / Advisory Committee on the Microbiological Safety of Food. Source: Wellcome Collection.

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    and TTP currently being undertaken. We have therefore recommended that clinical laboratories routinely examine all diarrhoeal stools for 0157 VTEC and that national prospective surveillance studies of HC, HUS and TTP are carried out. There is also a need to carry out case-control studies during outbreaks to provide better knowledge about sources, routes of transmission, risk factors and socio-economic costs associated with infection. Farm animals, especially cattle, are considered to be a reservoir of VTEC, but the true incidence and prevalence of 0157 VTEC in cattle in the UK are not known. There is also a lack of knowledge about the epidemiology of 0157 VTEC infections in farm animals, and husbandry and other factors which may affect herd infection and control. We have therefore recommended that appropriate studies are carried out. We have recognised the importance of hygienic slaughterhouse practices, whilst acknowledging that it is impossible in the short-term to ensure that animal carcases are totally free of O157 VTEC and other micro-organisms. Research into the effectiveness of processing aids such as carcase washes is also recommended. Laboratory diagnosis of O157 VTEC in clinical, food and environmental samples has developed over recent years with the use of liquid enrichment and the development of methods such as immunomagnetic separation. Methods for detecting non-O157 VTEC remain available only to reference laboratories. There is a need for research into improved isolation media for O157 VTEC, rapid methods to detect VTEC of all serogroups and Verocytotoxin in food and clinical samples. Improved sub-typing methods for VTEC are also needed, especially for 0157. We also believe that the currently available methods for testing food and environmental samples should be fully evaluated so that there is consistency of approach. From outbreak investigations, food appears to be a major vehicle of 0157 VTEC infection. A variety of foodstuffs have been implicated: undercooked minced beef products (especially beefburgers), raw cows’ milk and cheese, contaminated pasteurised milk and untreated water. Person-to-person spread occurs, probably by the direct faecal-oral route, and this has resulted in outbreaks in hospitals, child care centres, nursing homes, and other institutions. We have endorsed recently formulated public health measures for the control of outbreaks in general, and VTEC in particular, which are essential to prevent and control person-to-person transmission. We have considered how the foodborne transmission of VTEC can be prevented and controlled. We have recommended that food hygiene measures based on the HACCP system (which identifies those points in the food chain where pathogenic micro- organisms may be controlled or eliminated) should be taken in relation to the storage, handling and correct heat treatment of raw materials, including avoidance of cross- contamination. We have endorsed the Government’s Chief Medical Officer’s (CMO) advice, that beefburgers should be cooked until the juices run clear and there are no pink bits inside. We believe this advice should be reiterated to caterers and consumers, as should Government advice on the cooking of minced beef and minced beef products. 8