[Listeria and listeriosis: from farm to fork].

Listeria monocytogenes is a bacterium widely spread in the environment. Its persistence in industrial environment leads to food product contamination from the raw materials and constitutes a recurrent problem in food processing industry despite the use of cold chain procedures. L. monocytogenes is a foodborne pathogen causing severe and life-threatening infections that evolve mainly under sporadic mode, even if epidemics sometimes occur. Listeriosis causes mainly septicemia, central nervous system infections (meningitis and meningoencephalitis) and abortions. Listeriosis occurs primarily at risk groups of population like elderly people, pregnant women, neonates and patients with underlying diseases or impaired cellular immunity. In France, the epidemiological surveillance of listeriosis is based on two complementary approaches: the mandatory notification and the microbiological characterization by the National Reference Centre for Listeria of L. monocytogenes strains isolated from patients. The joined efforts of government and food producers have led to decrease significantly the incidence of listeriosis in France since 20 years and the number of epidemics. However, the recent observation of increasing number of listeriosis cases in most of the industrialised countries calls up to the attentiveness to reconsider the current rules and to reinforce the epidemiological surveillance of listeriosis in a context where susceptible people including the elderly are in increasing number.