[Epidemiology of listeriosis in Germany: a changing but ignored pattern].

Listeriosis is emerging as a food-borne disease. Although the incidence of clinical presentations is low, this infectious disease with a rather poor prognosis deserves attention. Approximately 20-30% of patients with recognized listeriosis die in spite of an appropriate antibiotic regimen. In the last two years the number of registered cases of listeriosis in Germany has more than doubled. This increase is clearly due exclusively to the rising number of infections in elderly persons, while the number of infections in newborns has remained constant. Genotyping does not show a conclusive correlation between human and food isolates. Since the human isolates belong to numerous different clones. There is no specific food or group of food items that can be held responsible for the infections. This view is also supported by the fact that listeriosis cases occur sporadically and not in outbreaks, making it highly unlikely that industrially produced and widely distributed food items are the cause. Furthermore, even within the food isolates there is a large diversity of clones. A comprehensive explanation for the changes in the epidemiology of human listeriosis has yet to be given.