INFECTIONS IN 18,000 INFANTS AND CHILDREN IN A CONTROLLED STUDY OF RESPIRATORY TRACT DISEASE. II. VARIATION IN ADENOVIRUS INFECTIONS BY YEAR AND SEASON1

Abstract

During a cross-sectional study of infants and children with respiratory tract disease, one or more adenovirus sero-types were recovered from throat and/or anal swab specimens in each of the 121 consecutive months of investigation. Control patients who were free of respiratory tract disease were found to be shedding adenovirus during 110 months of the study. Adenoviruses apparently initiated respiratory illness at a relatively steady annual rate, though there were distinct seasonal variations in frequency of infection. These viruses were recovered with highest frequency from patients with respiratory tract disease during the spring, early summer and early winter. Adenovirus-associated respiratory disease (as indicated by an excess of adenovirus recovery from respiratory disease patients as compared to matched controls) occurred most frequently in April for outpatients and in July for hospitalized patients. The incidence of adenovirus-associated upper respiratory tract disease could not be estimated, since rather arbitrary numbers of outpatients were sampled each month. In contrast, almost all patients who were hospitalized with lower respiratory tract disease were sampled, and in them the largest number of cases of adenovirus-associated lower respiratory disease appeared to occur in December. Approximately two-thirds of all serious respiratory tract disease which was causally associated with adenovirus infection apparently occurred during the months of December, January, June and July.