Definition of Parainfluenza

Parainfluenza: A disease due to an acute respiratory infection caused by a parainfluenza virus. Parinfluenza occurs usually in children. The clinical picture can range from a relatively mild influenza-like one to bronchitis, croup, and pneumonia.

Transmitted by aerosols, the virus is usually limited to the respiratory tract and does not invade the bloodstream (no viremia). Infection of very young children tends to lead to the most serious disease. The parainfluenzaviruses are members of the paramyxovirus group. See also : Human parainfluenza virus.