Parainfluenza virus type 3 outbreak in a neonatal intensive care unit.

Parainfluenza virus (PIV) is a respiratory pathogen in young children and is second only to the respiratory syncytial virus (RSV) as a cause of lower respiratory tract infection. PIV type 3 (PIV3) is the most severe. Herein we describe an outbreak of PIV3 in three infants in a neonatal intensive care unit. They were diagnosed on virus culture from pharyngeal swabs. We prevented the spread of the virus using standard infection control procedures and isolation of the symptomatic infants. One infant had severe chronic lung disease and was complicated with recurrent wheezing for a long time. Because RSV and PIV have many structural, pathogenic, epidemiologic, and clinical similarities, we speculate that PIV infection causes recurrent wheezing, as observed with RSV infection. Therefore, physicians must consider recurrent wheezing at the time of treatment of PIV infection early in life.