Gu YE, et al. – Researchers clarified characteristics of human parainfluenza virus type 4 (hPIV4) infection in Korea via assessing children admitted with respiratory tract infection. Pneumonia was the most common diagnosis in hPIV4 infection, followed by bronchiolitis and upper respiratory tract infection. Findings revealed that hPIV4 generally caused acute respiratory tract infection in summer and early fall in an irregular annual pattern. However, the most prevalent overall type of hPIV was hPIV3. The authors concluded that, in pediatric patients in Korea, hPIV4 is a significant common pathogen of respiratory tract infections.