The virus is especially important in children because it is responsible for approximately 40 percent to 50 percent of all cases of croup and 10 percent to 15 percent of bronchiolitis and bronchitis and some pneumonias. The incidence of parainfluenza is unknown but suspected to be very high. Illness causing only a runny nose and cold-like symptoms may pass as a simple cold rather than parainfluenza. Risk factors include young age. By school age most children have been exposed to parainfluenza virus.
Most adults have antibodies against parainfluenza although they can get repeat infections.
Parainfluenza Please read this Important notice . Please read it.