Epidemiology of rotavirus diarrhea in a prospectively monitored American Indian population.

Rotaviral diarrhea is endemic in most areas of the world, yet community-wide epidemics have not been reported in prospectively monitored populations. This prospective study of the etiology of diarrhea included biweekly visits to the homes of 10% of the population of the White Mountain Apache Indians and began in April 1981. During a three-week period beginning 21 October, 1981, 342 new cases of diarrhea were identified on different parts of the reservation. Rotaviral antigen, detected by an enzyme-linked immunosorbent assay, was identified in 169 (73%) of the 233 stool samples that were tested. Rotavirus was not detected in any of the stool samples taken six months before or after the epidemic. During the epidemic, respiratory symptoms were present in 44 (33%) of 135 rotavirus-positive patients compared with 17 (17%) of 98 rotavirus-negative patients (P less than .05). This rapidly spreading epidemic involving all areas of the reservation, in the absence of a common source of exposure of ill persons, suggests the possibility of respiratory transmission.