CLINICO-EPIDEMIOLOGIC STUDY OF HUMAN LIST ERIOSIS IN BARCELONA (SPAIN) (1990-1991)

BACKGROUND: The aim of this study was to determine the incidence of hu man listeriosis in Barcelona in addition to its clinical form of prese ntation, seasonability, risk groups and evolution. METHODS: A prospect ive study of the cases of listeriosis registered in the city of Barcel ona, Spain (population of 1,643,542 inhabitants) over the period from January 1, 1990 to December 31, 1991 was carried out. RESULTS: Fifty-f ive cases were reviewed with a global rate of incidence of listeriosis of 9.4 per one million inhabitants per year with predominance being o bserved in the summer months (39% in 1990, 42% in 1991). Ninety-one pe rcent of the cases were observed in non pregnant adults, with 86% of t he patients being immunosuppressed. Nosocomial listeriosis, diagnosed in 23 patients (42%), was predominant in the group with immunosuppress ive treatment (p = 0.0005). The main site of isolation was blood in 45 cases (82%), in the form of primary bacteremia in 30 cases (54%) with a significantly greater association with nosocomial listeriosis (p < 0.0005). Global mortality was 49%, being greater in the group of patie nts with nosocomial infection (p = 0.01) and with primary bacteremia ( p < 0.001). No patients without known risk factors or pertaining to th e perinatal group have died. CONCLUSIONS: The use of an active system of registration of listeriosis facilitates better knowledge of its inc idence, distribution and infection pattern thus allowing the early det ection of epidemic outbreaks with the aim of controlling such an infec tion, given the social implications and morbidity of this disease.