Pertussis (whooping cough) is a respiratory tract infection characterized by a paroxysmal cough. The most common causative organism is Bordetella pertussis (see the image below), though Bordetella parapertussis has also been associated with this condition in humans. Pertussis remains a significant cause of morbidity and mortality in infants younger than 2 years.
Signs and symptoms
Pertussis is a 6-week disease divided into catarrhal, paroxysmal, and convalescent stages, each lasting 1-2 weeks.
Stage 1 – Catarrhal phase
- Nasal congestion
- Low-grade fever
- Conjunctival suffusion
Stage 2 – Paroxysmal phase
- Paroxysms of intense coughing lasting up to several minutes, occasionally followed by a loud whoop
- Chronic cough, which may last for weeksPosttussive vomiting and turning red with coughing
The diagnosis of pertussis is made by isolation of B pertussis in culture. A polymerase chain reaction (PCR) test can also be performed.
- The culture specimen should be obtained during the first 2 weeks of cough by using deep nasopharyngeal aspiration
- For PCR testing, nasopharyngeal specimens should be taken at 0-3 weeks following cough onset
- The CDC recommends a combination of culture and PCR assay if a patient has a cough lasting longer than 3 weeks
- Early serial monitoring of white blood cell (WBC) counts is warranted
Goals of treatment
- Limit the number of paroxysms
- Observe the severity of cough and provide assistance when necessary
- Maximize nutrition, rest, and recovery
- Antimicrobial agents and antibiotics can hasten the eradication of B pertussisand help prevent spread
- Erythromycin, clarithromycin, and azithromycin are the preferred agents for patients aged 1 month or older