ABSTRACT
Listeria monocytogenes is an important foodbome pathogen capable of causing severe illness with a high mortality rate (Slutsker and Schuchat, 1999; Anonymous, 2000a). Susceptible groups include pregnant women, the elderly and the immuno-compromised. A wide range of foodstuffs has been implicated in outbreaks of listeriosis (Slutsker and Schuchat, 1999). An outbreak of L. monocytogenes occurred in 1981 in the Maritime Provinces of Canada. A case control survey of the implicated individuals indicated that coleslaw was the most likely cause of this outbreak (T ab le 3 ) . Further investigation revealed that the cabbage used for preparing the coleslaw might have been contaminated w ith !, monocytogenes from sheep manure at the farm (Schlech et al., 1983). Gastroenteritis has been reported as associated with listeriosis (Salamina et al., 1996) although the disease usually presents with other symptoms, such as fever, muscle aches and nausea. Pregnant women may suffer flu-like illness, and infection can lead to stillbirth or premature delivery. The elderly and immuno-compromised may develop bacteraemia or meningitis. The duration of the illness is variable. The case-fatality rate for listeriosis in industrialized countries is up to 30% but may be higher if adequate treatment is not provided (Anonymous, 2000a).
