[Distribution of Salmonella spp. serotypes isolated in Spain during a 4-year period (1993-1996)].

BACKGROUND: Knowledge of the epidemiology of salmonellosis over time is the main tool for public health care control of this disease which is the main cause of alimentary toxic infections in Spain. The epidemiologic marker of choice in this genus is the stable, simple technique of serotyping, which, given its wide use allows the follow up of the main serotypes over the years. This study analyzes the seasonal trends of the main serotypes of Salmonella received in the National Reference Laboratory of Salmonella and Shigella in Spain (LNRSSE) from 1993-1996. MATERIALS AND METHODS: Serotyping of the strains of Salmonella received in the LNRSSE during the years of the study with sera induced in our laboratory and commercial laboratories was undertaken. The strains of human origin the trends of the main serotypes were evaluated with the Mantel-Haenszel chi 2 test. RESULTS AND DISCUSSION: Nineteen thousand seven hundred forty-one strains of Salmonella from most of the autonomous communities of Spain were analyzed. Ninety-two point one two percent of the strains of human origin were received from laboratories that sent strains throughout at least three of the four years of the study, thereby allowing evaluation of the serotype trends for this group of strains. The enteritidis and typhimurium serotypes were the most frequently observed. In these serotypes the strains of human origin were typed with double the frequency of that found among those from food and three-fold greater than that found among the strains of environmental origin. Typhimurium was the more frequently found than enteriditis in the group of strains from diseased animals. Finally, the significant statistical increase of the hadar serotype, which surpassed the virchow serotype in recent years, is of note.