6-week disease divided into catarrhal, paroxysmal, and convalescent stages, each lasting from 1-2 weeks
Stages of disease
- Stage 1: The initial (catarrhal) phase is indistinguishable from common upper respiratory infections with nasal congestion, rhinorrhea, and sneezing, variably accompanied by low-grade fever, tearing, and conjunctival suffusion. Pertussis is most infectious when patients are in the catarrhal phase, but pertussis may remain communicable for 3 or more weeks after the onset of cough.
- Stage 2: Patients in the second (paroxysmal) phase present with paroxysms of intense coughing lasting up to several minutes. In older infants and toddlers, the paroxysms of coughing occasionally are followed by a loud whoop as inspired air goes through a still partially closed airway. Infants younger than 6 months do not have the characteristic whoop but may have apneic episodes and are at risk for exhaustion. Posttussive vomiting and turning red with coughing are common in affected children.
- Stage 3: Patients in the third (convalescent) stage have a chronic cough, which may last for weeks
- Culture specimen (deep nasopharyngeal aspiration or holding a flexible swab in the patient’s posterior nasopharynx for 15-30s or until a cough is produced)
- Erythromycin (to limit secondary transmission)
- Vaccination (see immunization section)
- Treat close contacts (family, daycare)