The Tecumseh Study. XVI: Family and community sources of rotavirus infection.

The effect of age on transmission of rotavirus infection within households and on the risk of infection from outside of the household was investigated through analyses of serum pairs. These paired specimens had been collected from individuals of all ages in families of diverse age composition in Tecumseh, Michigan. Serologic observations on 1,508 individuals divided into 0-1, 2-4, 5-9, 10-17, and 18+ year age groups provided infection determinations on 3,311 person-seasons during the 1977 through 1981 rotavirus seasons. Infection occurring in an individual in each age group was generally associated with infection in all other age groups in the household. Despite these associations by household, two different means of estimating the proportion of all infections acquired in the household yielded estimates of only 17 and 20%, indicating the importance of community acquisition of infection. Very young children had a very small percentage of their infections acquired in the household, while progressively older ages had an increasing percentage of infections acquired there. These results indicate that a strategy of indirectly protecting infants from infection by preventing infection in their household contacts would be inefficient.