Serious Complication Rates of Pertussis
Pertussis carries significant complication rates that vary dramatically by age, with infants under 12 months experiencing the highest rates of serious complications and mortality. 1
Complication Rates by Age Group
Infants (<12 months)
- Hospitalization rate: 63% of infants with pertussis 1
- Pneumonia: 13-22% (radiographically confirmed) 1
- Seizures: 3% 1
- Encephalopathy: 0.9% 1
- Death rate: 0.6% overall for infants, with highest risk in youngest infants 1
Adults
- Hospitalization rate: up to 3% (12% in older adults) 1
- Pneumonia: up to 5% 1
- Rib fracture: up to 4% from paroxysmal coughing 1
- Loss of consciousness/cough syncope: 3-6% 1
- Death: extremely rare in adults without serious underlying conditions 1
Risk Factors for Severe Complications
- Age: Infants <2 months have the highest risk of severe disease and death 1
- Vaccination status: 78% of fatal cases had received no doses of pertussis vaccine 2
- Prematurity: 60% of fatal cases were born at ≤36 weeks gestation 2
- Maternal factors: Younger maternal age (median 20 years vs national median of 26.3 years) 2
- Underlying conditions: Adults with serious medical conditions (e.g., severe diabetes, multiple sclerosis, immunosuppression, myelofibrosis, COPD) are at higher risk for fatal outcomes 1
Common Complications
Respiratory Complications
- Pneumonia (most common serious complication)
- Pneumothorax
- Apnea (particularly in infants)
- Cyanosis (37.5% in confirmed infant cases) 3
- Hemoptysis 1
Neurological Complications
- Seizures
- Encephalopathy
- Loss of consciousness/cough syncope
- Loss of concentration/memory 1
Other Complications
- Urinary incontinence (common in women) 1
- Inguinal hernia 1
- Herniated lumbar disc 1
- Subconjunctival hemorrhage 1
- Carotid dissection (rare) 1
- Severe weight loss 1
- Rectal prolapse (in infants) 4
Clinical Implications
- Early recognition and treatment is crucial, especially in infants and those with risk factors
- Vaccination remains the primary prevention strategy, with recommended 5-dose series of DTaP vaccine 5
- Postexposure prophylaxis should be considered for all household contacts regardless of age or vaccination status 5
- Isolation of infected individuals for 5 days after starting antibiotic therapy 5
Key Pitfalls to Avoid
- Delayed diagnosis in infants: Young infants may present with apnea and bradycardia without classic cough 1
- Underestimating disease in adults: Adults serve as important reservoirs for transmission to vulnerable infants 1
- Inadequate prophylaxis: Failure to provide prophylaxis to household contacts can lead to transmission to unvaccinated or incompletely vaccinated infants 5
- Incomplete vaccination: The majority (89.3%) of confirmed pertussis cases in infants occur in those too young to be fully vaccinated or under-vaccinated 3
The economic burden of pertussis is substantial, with direct hospitalization costs exceeding $1,000 per year, not including indirect costs such as parental work loss 6, 3.