Pertussis, or whooping cough, is a highly contagious disease involving the respiratory tract. It is caused by a bacterium that is found in the mouth, nose and throat of an infected person. Pertussis can occur at any age. Pertussis is primarily spread by direct contact with discharges from the nose and throat of infected individuals. Frequently, older siblings who may be harboring the bacteria in their nose and throat can bring the disease home and infect an infant in the household.
Pertussis begins as a mild upper respiratory infection.
Initially, symptoms resemble those of a common cold, including sneezing, runny nose, low-grade fever and a mild cough. Within two weeks, the cough becomes more severe and is characterized by episodes of numerous rapid coughs followed by a crowing or high pitched whoop. A thick, clear mucous may be discharged. These episodes may recur for one to two months, and are more frequent at night. Older people or partially immunized children generally have milder symptoms.