It causes severe spells of coughing which can interfere with eating, drinking, and breathing. Some people who recover from pertussis may suffer from mental retardation. Pertussis can occur in all ages but is most common in children younger than 5 years, especially infants less than 1 year of age. Pertussis is spread through the air after an infected person coughs or sneezes. Other people then breathe in infected droplets.
Pertussis starts like a cold with symptoms of runny nose and an irritating cough.
Within 1 to 2 weeks the cough develops into coughing fits - a series of violent coughs during which the victim struggles for breath. The coughing is followed by a gasping for air which produces a high-pitched whooping sound. The coughing fits occur more frequently at night and are often followed by vomiting. Without treatment an infected person can spread the disease from the time he or she starts coughing up to 3 weeks after the start of the coughing fits. After 5 days of treatment with the antibiotic, erythromycin, an infected person cannot spread the disease.