Asymptomatic excretion of rotavirus before and after rotavirus diarrhea in children in day care centers.

A 12-month prospective study of diarrhea in children in day care centers (DCCs) provided an opportunity to evaluate the duration of excretion of rotavirus from children before and after episodes of diarrhea caused by rotavirus. Ninety-nine episodes of rotavirus diarrhea occurred in 94 children. Asymptomatic rotavirus excretion occurred in 50% of children tested on the day before diarrhea occurred, 31% two days before diarrhea, and 9% in days 3 through 5 before diarrhea. Two children had positive specimens 11 and 13 days, respectively, before illness. During the week after cessation of diarrhea, 32% had positive specimens; 12% had positive stool specimens during the second week after diarrhea episodes. Electrophoretic testing of rotavirus RNA from stool specimens showed different electrophoretic migration patterns of the genomic RNA among the pairs tested, but the genomic RNA was the same within each pair of symptomatic and asymptomatic specimens. Excretion of rotavirus before and after diarrhea is common in children in DCCs; the role that asymptomatic excretion plays in the spread of this disease within DCCs is unknown.