Epidemiology and transmission of rotavirus infections and diarrhoea in St. Lucia, West Indies.

To determine the epidemiology and risk factors of rotavirus infections in St. Lucia, 229 children in three valleys with varying levels of sanitation were studied for 2 years. A four-fold rise in complement fixation antibody to rotavirus antigen was used in paired samples as evidence of recent infection. Results showed that forty-eight per cent of infants experienced at least one infection during a two-year period, and 17% of children were reinfected. Infections occurred within the first months of life and peaked between 6 and 23 months of age. The peak infection coincided with the dry season in each age group. Children breast-feeding had fewer infections. Although crowding within the home was significantly associated with repeated infection, the incidence of infection was not affected by the degree of sanitation. Other studies in the region, using recently developed techniques, concur with these findings which advance our understanding of the epidemiological importance of rotavirus in St. Lucia. Although these studies provide insights into the risk factors for rotavirus infections, other studies are required to determine whether investments should be focused on improved sanitation or immunization or both.