Seasonal Patterns of Acute Infection in Tecumseh, Mich

Abstract

Incidence of respiratory and of gastrointestinal illnesses were determined by surveillance of families in Tecumseh, Mich. Repetitive seasonal patterns of virus isolation were observed. In two of the three years of surveillance, there was a sharp peak of respiratory illness in September associated with the isolation of rhinoviruses. Parainfluenzaviruses were frequently isolated in late fall and respiratory syncytial virus for a limited period each respiratory year in the winter or spring. Gastrointestinal illnesses were most common in winter, least in summer, with spring and fall intermediate, a pattern similar to that found with respiratory disease. Gastrointestinal disease was negatively correlated with temperature in spring and fall and positively in summer, which suggested that a different group of pathogens might be involved in the latter season. The early fall peak of respiratory illness was found to be associated with a fluctuation in sunshine and rainfall four and six weeks before.