Nosocomial gastroenteritis in two infant wards over 26 months

We retrospectively reviewed 209 cases of nosocomial diarrhea in two infant wards at St Göran's Children's Hospital. They occurred from April 1987 to May 1989, when 3105 patients spent 26,355 hospital days. The hospital is a 250-bed tertiary center with university affiliation. Fourteen percent of patients at risk developed nosocomial diarrhea, and the relative attack rate was 1.1 episodes per 100 hospital days. A probable viral etiology was found in 47% of patients. Rotavirus was most frequent and occurred during the community rotavirus seasons. Also small, round, structured viruses were common, and two outbreaks of astrovirus gastroenteritis occurred. Failure to detect a virus was particularly common among infants younger than 4 months. However, a seasonal distribution and peaks concordant with defined clusters in older patients, suggest also that some of these detection-negative cases may have a viral etiology.