Campylobacter jejuni is the most commonly isolated bacterial pathogen associated with diarrhoea in the UK (Ketley 1997) and other industrialized countries (Mead et al. 1999). Historically, the North-west region of England has had a higher than average rate of infection (Jones and Telford 1991) but otherwise the data in that area reflect the trends observed in the UK national data, i.e. an increase over the years in the annual number of cases since 1981, and a late spring/early summer annual peak. There is also a lower secondary autumn peak.
Campylobacter jejuni colonizes the gastrointestinal tract of a broad range of animals but the most important risk factor for humanCampylobacter infection is widely held to be the handling and consumption of raw poultry and cross-contamination to uncooked products (Tauxe 1992). However, there is now a growing body of molecular evidence that suggests the significance of non-poultry sources of human clinical infection has been underestimated. This review focuses on the significance of Campylobacter colonization of cattle and sheep, the incidence and rate of shedding among these animals and the role of the dairy farm as a reservoir of Campylobacter infection.
Aim: This is a review of the natural Campylobacter colonization and transmission among ruminant livestock in the dairy farm environment.
Methods and Results: Using cultural detection methods and enumeration techniques the distribution of Campylobacter in ruminant animals at birth, on the farm, at slaughter and in the farm environment have been examined. Colonization and shedding rates are higher among young animals while patterns of shedding in adult animals may be seasonal. Stored and land-dispersed slurries provide a reservoir for scavenging birds and flies and a source for runoff.
Conclusions: The dairy farm plays a significant role in the dissemination of Campylobacter sub-types that can cause disease in the human community.
Significance and Impact of Study: An understanding of the role of the dairy farm in the environmental cycle of Campylobacter is required in order to devise intervention strategies.