Rotaviruses are a major cause of severe diarrheal illness in children, who frequently require hospital admission because of the severity of symptoms. Since clinically significant infection can result from the ingestion of just one plaque-forming viral unit, it is important to determine the time period during which virus particles may be shed by children recovering from acute infection. Richardson and colleagues evaluated the length of time that rotavirus was excreted following severe acute infection in children.

Thirty-seven children aged one to 39 months were included in the study. All of the study subjects were admitted to an Australian hospital because of severe confirmed rotavirus infection but were otherwise healthy, with normal serum immunoglobulin levels. Fecal specimens were examined for rotavirus using molecular biologic techniques with very high sensitivity and specificity. Specimens were collected daily for 14 days following admission to the hospital and then weekly for at least 100 days. Approximately 26 specimens were collected from each child.

Although the median duration of viral excretion was 10 days, the range was four to 57 days. In 16 children (43 percent), viral shedding ceased within 10 days of hospital admission. In 11 children (30 percent), viral excretion was detectable for 22 to 57 days. Many of the children with extended periods of viral excretion had intermittent viral shedding. It was not possible to predict which children would have long periods of viral shedding on the basis of age, duration of diarrhea or symptom severity. Children with extended excretion showed different patterns of IgA antibody response to infection and had more frequent recurrence of diarrhea during convalescence.

The authors conclude that approximately one third of immunocompetent children with severe rotavirus infection continue to secrete potentially infective virus particles for at least three weeks following hospital admission. In some cases, excretion may continue for up to 57 days. Children who secrete virus for prolonged periods cannot be easily distinguished from other children with rotavirus infection and could be important sources of infection in the community.