Pertussis, also known as whooping cough, is a respiratory infection caused by the bacteria Bordetella pertussis. It is highly contagious and most harmful to infants and children. Most children get pertussis from adults and not from other children. Children can get pneumonia and in rare cases, can die from pertussis (especially in children less than one year of age).
Symptoms usually occur in two stages. The first stage begins like a cold, with a runny nose, sneezing, and a low-grade fever. The second stage includes uncontrolled coughing spells. The second stage can last 6-10 weeks. It is very contagious during the early stages of the illness and becomes less contagious by the end of three weeks. Antibiotics can shorten the contagious period.