Pertussis

Definition

Alternative Names

Causes

Pertussis, also known as whooping cough, is caused by infection with the Bordetella pertussis bacteria. The infection is spread through the air by droplets from the breath of an infected person. The incubation period is usually 7 days.

Whooping cough can affect people of any age. Prior to widespread immunization, the disease was most common in infants and young children. Now that most children are immunized before school age, a higher percentage of cases are seen among adolescents and adults.

However, about 40% of cases still occur in infants younger than 6 months of age. Early immunization can usually prevent this serious disease, which can sometimes be fatal or lead to permanent disability when it affects babies.

The bacteria invade the nose and throat, the breathing tube (trachea), and the lungs. The infection usually lasts 6 weeks. It starts with symptoms similar to the common cold, and progresses to spasms of coughing after 10 to 12 days.

The cough is characterized by 2 or 3 repeated coughs without inhaling. Typically, the person's face becomes redder with each cough, then subtly bluish.

In children, the coughing spasm often ends with a characteristic "whoop" when breathing in. The whoop is rare in patients under 6 months of age and adults. It is most often seen in children between 6 months and 7 years old. Very young children, older kids, and adults usually just have severe cough spasms (several in a row) that may cause vomiting.

The child may momentarily lose consciousness at the end of a coughing spell. During this stage, there is heavy mucus production. Coughing spells may lead to vomiting. Pertussis should always be considered when vomiting occurs with coughing. In infants, choking spells are common.

Recovery begins about four weeks after symptoms begin and may take several weeks. Coughing spasms may return over the next several months, usually due to irritation from an upper respiratory infection.

Immunization may reduce the symptoms of pertussis in those cases where it does not produce complete immunity. However, when the symptoms are not obvious, pertussis may be difficult to diagnose.