Diarrhea accounts for 9 to 13 percent of hospitalizations in children younger than five years of age. Epidemiologic characteristics of rotavirus, such as winter seasonality, predisposition to rotavirus infection in children four to 23 months of age and geographic migration of rotavirus epidemics, have been used to estimate that this infection causes one third of all pediatric hospitalizations associated with diarrhea. Parashar and associates conducted a retrospective analysis to assess the morbidity from diarrhea and to estimate the disease burden of rotavirus to determine the potential benefit of a rotavirus vaccine.

Data on approximately 1 million children up to six years of age who were enrolled in four health maintenance organizations were transmitted to the Centers for Disease Control and Prevention. Retrospective analysis of data from October 1992 through September 1994 included all events for which a diagnostic code specific to diarrhea was listed. Diarrhea was associated with 6.3 percent of all hospitalizations among children at the four sites. The majority of hospitalizations related to diarrhea (65.7 percent) were of unknown etiology. Rotavirus was specifically recorded as the cause in only 2.7 percent of hospitalizations. Fifty-seven percent of all diarrhea-associated hospitalizations were reported among children from four to 23 months of age, the most common age for diarrheal infections caused by rotavirus. Each year of the study period, the number of hospitalizations and visits to the emergency department associated with diarrhea peaked in the winter months.

The authors' findings indicate that diarrhea was an important cause of morbidity among these children. Further studies are needed to determine the exact burden of rotavirus on diarrheal illness, but the seasonality and age distribution of diarrheal illnesses hint strongly of the morbidity of rotavirus in this population. Laboratory-confirmed data on rotavirus infections are also needed to determine the potential cost-effectiveness and impact of rotavirus vaccines.

editor's note: A rotavirus vaccine (Rota Shield) has recently been recommended for approval by a panel from the U.S. Food and Drug Administration. The vaccine protects against the four most prevalent strains of rotavirus that cause symptoms. Administration of three doses is recommended at two, four and six months of age. The first dose should be given before six months of age because of the higher incidence of fever when the vaccine is first administered to children older than this age. Immunogenicity of the vaccine is not affected by the simultaneous administration of diphtheria, tetanus, pertussis, Haemophilus influenzae type B (DPT-Hib) vaccines, oral poliovirus vaccine (OPV), inactivated poliovirus vaccine (IPV) or hepatitis B (HepB) vaccine. The American College of Infectious Disease Pediatricians supports the use of this vaccine. The American Academy of Family Physicians is reviewing the trial data before making a final determination about including this vaccine among those recommended for use in children.—r.s.