Reducing risks from E. coli 0157 on the organic farm

Abstract

E.coli 0157 is a bacterial pathogen of the human intestinal tract which is carried in certain species of livestock and wildlife without ill effect. Such organisms are termed zoonotics. Various types of Campylobacter and Salmonella are other major causes of food borne illness that like E. coli 0157, are zoonotic in livestock and appear to have been on the increase in recent decades. E. coli 0157 is particularly hazardous because of the very low number of organisms that can cause infection and because of serious complications that can result from infection, especially in infants and the elderly. As well as from contaminated food, E. coli 0157 can be acquired through casual contact with manure and with fecal contaminated surfaces and water. Thus farm residents and workers should be aware of the nature of E. coli 0157 and of personal measures they can take to reduce the risk of infection. Reducing the levels of zoonotics in farm animals is seen as a key component of strategies to reduce the occurrence of food borne infections generally. A number of the existing practices of organic farming could be expected to discriminate against E. coli 0157. However, none can ensure its absence and the routes by which 0157 moves into farms apply to organic farms, for example via birds that have been feeding on a farm with a high level of E. coli 0157. Some provisional guidelines for reducing levels of E. coli 0157 on organic farms and the risk to farm workers and residents are offered. They are pertinent also to gardeners who use manure or buy bulk compost.