Impact of human adenovirus serotype 7 in hospitalized children with severe fatal pneumonia in the Philippines.

Human adenovirus (HAdV) serotype 7 is an important etiological agent of severe childhood pneumonia. The aim of this study was to define the role of HAdV7 and to describe its clinical and molecular epidemiological characteristics in the Philippines in 2011. HAdVs were detected by viral culture, and a partial region of hexon gene was sequenced. A total of 700 patients were enrolled, of which 22 (3.1%) died. Nine (1.3%) HAdV cases were confirmed, of which 7 were positive for HAdV7, 1 for HAdV3, and 1 for HAdV5. Among the 9 HAdV-positive cases, 4 (44%) with HAdV7 died. Molecular analysis revealed that all HAdV7 isolates were closely related to genome type h strains. This study demonstrated the significance of HAdV7 as an etiological agent of severe pediatric pneumonia with a high fatality rate. Hence, continuous monitoring is required to define the clinical and public health significance of HAdV7 infection.