The aim of the investigation was to compare clinical and epidemiological characteristics of acute bacterial and viral diarrhea diseases in children. The authors describe a cohort of children up to 5 years of age admitted for acute diarrhea diseases to Infection Clinic of Faculty Hospital in Plzen in 2002. In the total of 1.735 patients in 2002, 392 children were hospitalized. Two hundred and eighty seven children (73 %) were admitted for diarrhea diseases. Etiology was verified in 67.2% of all cases of acute gastroenteritis. The diarrhea in this age group was most frequently caused by rotaviruses (29.9%), salmonellae were confirmed in 18.5% and Campylobacter jejuni was found in 9% of patients. The course of salmonelloses and campylobacterioses was not accompanied by extraintestinal complications. The most serious course of rotavirus infections with signs of medium-degree dehydration was encountered in 20% and that of serious degree in 8%. Nosocomial infections with retroviruses occurred in 4% of children hospitalized for diarrhea diseases. Nosocomial infections were the cause of extended hospitalization by four days on the average. The rotavirus infections proved to be the most frequent and most serious cause of acute diarrhea diseases in children up to five years of age, displaying a seasonal incidence and being complicated by severe dehydration.

        Key words: acute gastroenteritis, children, epidemiology, rotavirus infections, nosocomial rotavirus infections