Pertussis (whooping cough) is a potentially devastating bacterial infectious condition involving the human respiratory tract. The disease begins with mild upper respiratory symptoms similar to common cold (catarrhal stage) lasting an average of two weeks which progresses to paroxysms of cough (paroxysmal stage) characterized by inspiratory whoop. Subsequently the symptoms wane gradually over a few weeks (convalescent stage) to potentially months. The incubation period is 7-10 days. Fever is usually absent or minimal.
Whooping cough in infants younger than 6 months of age can be atypical with a short catarrhal stage, gagging, gasping or apnea as prominent early manifestations; absence of whoop; and prolonged convalescence. The disease can be severe in young infants particularly if unimmunized or preterm with case fatality rate of approximately 1%. The duration of classic pertussis is 6 to 10 weeks. Complications among infants can include pneumonia (22%), seizures (2%), encephalopathy (0.5%), and even sudden death. The illness in immunized children and adults can be mild and unrecognized. In adults the disease may only present with prolonged cough. Infected people are most contagious during the catarrhal stage and the first two weeks after cough onset.
Factors affecting the spread of whooping cough include...
