[Listeriosis 1985-1995: microbiologic and epidemiologic aspects]

Listeriosis is an emerging foodborne infection caused by L. monocytogenes (L. m.), mainly identified in industrialized countries. It is a severe disease (meningitis, septicaemia, abortion) which preferentially affects individuals whose immune system is perturbed (pregnant women, newborns, immunocompromized patients and the elderly). Epidemiology is characterized by a background of sporadic cases on which may be surimposed outbreaks. Progresses in microbiology during the last decade (detection and typing of L. m., better understanding of L.m. ecology...) and epidemiological investigations (increased use of case-control studies) demonstrated that all kind of foods, at each step of the food chain, can transmit the disease. In many respects, L.m. differs from most recognized foodborne pathogens: it is ubiquitously present in nature, resistant to various kind of environments, microaerophilic and psychrophilic. Its tenacity in industrial environment and its capability to survive in food over extended period of time under adverse conditions made this bacterium the hottest topic for industrials during the last decade.