Duration of Excretion of Rotavirus

Source: Richardson S, et al. Extended excretion of rotavirus after severe diarrhoea in young children. Lancet 1998; 351:1844-1888.

Rotaviruses are the major cause of severe diarrhea during childhood. It has been reported that almost all immunocompetent children experiencing a primary rotavirus infection cease shedding rotavirus in their stools within 10 days of the onset of their symptoms, and only 1-2% of children examined after discharge from the hospital have excreted the virus for longer than 20 days. In these studies, virus excretion was identified by relatively insensitive techniques such as enzyme immunoassay (EIA), electron microscopy of fecal extracts, and gel electrophoresis looking for viral RNA. Since ingestion of as little as one viral unit can cause human infection, duration of possible infectivity after a rotavirus infection must be established by the most sensitive tests.

Richardson and associates from the Children’s Hospital in Melbourne, Australia, studied the duration of fecal excretion of rotavirus in 37 children who were admitted to their hospital with severe rotavirus diarrhea. Sequential fecal specimens were collected from each child during 100 days of surveillance. Each specimen was screened for the presence of rotavirus by EIA and also by amplification of genome double-stranded viral RNA using reverse transcription polymerase chain reaction.

Duration of excretion of rotavirus in these children ranged from four to 57 days. Excretion ceased within 10 days in 16/37 (43%) children and within 20 days in 26/37 (70%) children. Extended excretion of virus was extended to 25-57 days in the remaining 11 children. Extended excretion was associated with recurrence of mild gastrointestinal symptoms during convalescence.

Because prolonged fecal excretion of rotavirus may occur in as many as 30% of children with severe rotavirus diarrhea, the risk of transmission of this disease to others may be greater than previously believed.—CH