Pertussis 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 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.