Bordetella pertussis (whooping cough)
Whooping cough is a highly infectious bronchitis caused by the gram-negative coccobacillus Bordetella pertussis, marked by catarrhal, paroxysmal, and convalescent stages with lymphocytosis; diagnosis is clinical, confirmed by nasopharyngeal PCR, and treated with azithromycin plus prophylaxis of close contacts.
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What this article covers
- Overview
A highly infectious bronchitis of the ciliated respiratory epithelium: caused by Bordetella pertussis, a gram-negative, aerobic coccobacillus that spreads by respiratory droplets and requires droplet precautions with a mask.
- Epidemiology
Adolescents and young adults are the primary reservoir: vaccine-induced immunity from childhood DTaP wanes by adolescence, so pertussis should not be excluded in a young adult with paroxysmal cough.
- Risk factors
Age under 6 months, incomplete or absent DTaP series: the single strongest predictor of severe or fatal disease.
- Pathophysiology
Bacterial adherence to ciliated respiratory epithelium: via filamentous hemagglutinin and pertactin, establishing localized infection without systemic bacteremia.
- Clinical features
The illness passes through three defined stages, and recognizing the stage carries the diagnosis: catarrhal (1 to 2 weeks of nonspecific rhinorrhea, low-grade fever, and mild cough, when the patient…
- Differential diagnosis
Viral bronchiolitis (RSV): wheezing and increased work of breathing predominate in a young infant, without the discrete paroxysm-whoop pattern; typically a winter seasonal illness.
- Diagnosis
Pertussis is a clinical diagnosis established by the staged history: paroxysmal coughing fits with an inspiratory whoop and post-tussive emesis following a 1- to 2-week catarrhal prodrome (or, in an…
- Management
First, risk-stratify by age: hospitalize every infant under 6 months of age for continuous cardiorespiratory and apnea monitoring, given the risk of hypoxia, apnea, and respiratory failure…
- Complications
Apnea and hypoxia in infants: the most immediately life-threatening complication, particularly under 2 to 3 months of age.
- Prognosis
Age and immunization status drive outcome: infants under 6 months, especially the unvaccinated under 2 months, carry the highest risk of hospitalization, complications, and death.
- Prevention
Routine childhood immunization with the DTaP 5-dose series at 2, 4, 6, and 15 to 18 months, and 4 to 6 years, is the foundation of prevention.
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