Infection and Disease in a Group of South Indian Families

A continuing longitudinal study of infection and disease in a group of South Indian families began in September, 1965, in three semiurban areas of Vellore, South India. Families were chosen from three localities using a cluster sampling technique and were visited every 3 to 4 days by public health nurses for the collection of information concerning illness in family members. Laboratory specimens for viral and bacterial study were collected on a routine basis at 4 weekly intervals from preschool children and also occasionally from adults. The characteristics of the study area, the population, and the sample families, are tabulated.