[Epidemic of listeriosis in Western France (1975--1976)]

Cases of human listeriosis have recently increased in Western France (Maine-et-Loire and Mayenne); until 1974, there were only 15 documented cases yearly where as in 1975, there were 113 cases, and in 1976, 54 documented cases at the hospitals of Angers and Laval. Included amongst the clinical manifestations observed, were 126 cases of materno-fetal infections and 41 cases of either septicemia or meningo-encephalitis. The bacteriological study revealed a certain variability of biological characteristics examined, the overwhelming frequence of bacteria of the strain 4 b and the predictable sensitivity of this strain to antibiotics commonly employed in cases of listeriosis. The human cases were notably more frequent between January and June but their geographical distribution was not related to cases of either animal disease nor listeria that was isolated from corn silage. In this report, we propose an etio-pathological explanation for this epidemic.