an epidemiological study of listeriosis in dairy cattle

CHAPTER 2
The frequency and some characteristics of clinical
2. 1. Introduction
listeriosis in dairy cattle in England
Listeriosis is an infectious disease caused by micro-organisms of the genus Listeria
(Farber and Peterkin 1991, reviewed by Radostits and others 1994). Three distinct patterns
of clinical disease are recognised in both animals and people; encephalitis, abortion,
septicaemia. (Gray and Killinger 1966). In addition, mastitis (Gitter and others 1980, Boury
and others 1995), iritis and keratoconjunctivitis (Kummeneje and Mikkelsen 1975, Morgan
1977, Watson 1989, Bee 1993) have also been associated with Listeriosis in ruminants in
recent years.
Listeria has attracted considerable attention owing not only to increased reports of
clinical disease in animals (Gitter 1989) and people (MacLauchlin and others 1991) but
also to its implication as a food-borne pathogen (Schlech, 1991).
Although much progress has been made in the isolation, identification and typing of
listeria the epidemiology of listeriosis remains poorly understood (Donachie and Low
1995). There has been no study of the prevalence and incidence of listeriosis in dairy cattle
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