Parainfluenza virus type 4 infections in pediatric patients

Background. The purpose of this study was to describe the clinical characteristics and epidemiology of parainfluenza virus type 4 infections in pediatric patients. Methods. Hospital records of 13 patients from whom parainfluenza virus type 4 was isolated were retrospectively reviewed, Results. Parainfluenza virus type 4 infection was associated with upper respiratory tract disease, severe lower respiratory tract disease requiring hospitalization in 10 of 13 patients and aseptic meningitis. Nine of the 10 hospitalized patients were <24 months old (mean age, 5.3 months) and required hospitalization for 4 to 25 days (mean, 5.5 days). Conclusions. Serious illnesses associated with parainfluenza virus type 4 infections are more common than previously recognized.