Surveillance of adenovirus respiratory infections in children in Osaka, Japan

Abstract

Human adenovirus (HAdV) strains isolated from respiratory specimens of 139 children between 2008 and 2015 were analyzed with the intent of evaluating the endemic situation of HAdV infections in Osaka, Japan. The cases increased in spring and winter, and the infections were confirmed mainly in children aged ≤ 5 years, comprising 91.9% of the total population examined. Molecular typing of the isolates revealed that the most common types belonged to HAdV-B and HAdV-C, and a case of co-infection with HAdV-C1 and HAdV-C2 was confirmed. The median age of HAdV-E cases were higher than that of HAdV-B and -C cases. These results revealed age and seasonal distribution of respiratory infections caused by HAdVs in children in Osaka, and indicate that the majority of children might have acquired immunity through infection with endemic HAdVs before school age.