Salmonellosis: an epidemiologic study.

Background: Salmonella species commonly produce acute gastroenteritis. The clinical course may be affected by factors such as age, immunosuppression, and underlying disorders. Objectives: To investigate clinical and laboratory differences in the infected population and the risk of complications according to the different age groups. Methods: The records of 295 patients with positive cultures for Salmonella were divided into six age groups and reviewed retrospectively for the years 1994-1997. Demographic, clinical and laboratory data, extraintestinal manifestations, underlying disorders, organism source, and susceptibilty to antibiotics were analyzed. Results: We found that 88.5% were only stool positive, 9.2% had positive blood cultures, and 2.4% were positive in both blood and stool; 3.6% were found to have underlying disorders. Anemia, disturbed liver function tests and hypoalbuminemia were the most common pathologic laboratory findings. Salmonella serogroups B and D were isolated most frequently. The rate of positive blood cultures increased significantly during the years, as did resistance to ampicillin and trimethoprimsulfamethoxazole. Salmonella infection has two peaks of incidence: at ages 1-5 and 15-65 years. Bacteremia was prominent in the extreme ages. Conclusions: Salmonella infection has a different clinical presentation in different age groups. The significant increase in the rate of bacteremia in the extreme age groups necessitates a different attitude and management for these heterogeneous patient populations.