Epidemiology of rotavirus infection and gastroenteritis in prospectively monitored Argentine families with young children.

A prospective study was carried out in 49 families of newborns in Avellaneda District, Argentina, recruited when the mother was in the last trimester of pregnancy and followed until the newborn was aged two years, to study the epidemiology of rotavirus infection under natural conditions. Weekly surveillance of all family members for diarrhea and rotavirus-related diarrhea was carried out from May 1983 to July 1986. Serum samples were also collected every six months to study the incidence of rotavirus infection in all family members. The peak of diarrhea incidence was observed in children aged less than two years (2.1 cases per person-year). Rotavirus infection was a common rather than a sporadic phenomenon (0.63 cases per person-year, on average) in all age groups, and at least 61% of rotavirus infections were reinfections. In contrast, the peak of rotavirus infection in seronegative persons (0.58 cases per person-year) and the peak of rotavirus-related diarrhea incidence (0.25 cases per person-year) were found during the first year of life. These results showed that infants aged less than one year are the most appropriate candidates for a rotavirus vaccine in the Avellaneda population. However, improvements in sanitary conditions and personal hygiene and education of the high-risk population should be considered the primary means of reducing infectious diarrhea in Argentina.