an acute infectious disease of man resembling whooping cough (pertussis) in etiology, epidemiology, and clinical symptoms. Parapertussis may occur at any age, but it generally affects children three to five years of age. It is rare among children less than one year of age. The source of infection is a sick person and the mode of transmission is by airborne droplets. The patient is infectious for two weeks from onset of the disease.

The main symptom is a cough, sometimes paroxysmal, as in whooping cough, but the attacks are less frequent and of shorter duration. Rhinitis and a normal or slightly elevated body temperature are common. The usual outcome is complete recovery; complications are extremely rare. Vaccination or a previous history of whooping cough do not result in immunity to parapertussis. The duration and method of isolating patients are the same as in whooping cough, but only children under one year of age are isolated.