What is the recommended approach for managing pertussis (whooping cough)?

Management of Pertussis (Whooping Cough)

Start macrolide antibiotics immediately when pertussis is suspected—do not wait for laboratory confirmation—and isolate the patient for 5 days from treatment initiation to prevent transmission. 1, 2

Diagnosis

Clinical Suspicion

• Suspect pertussis when cough persists ≥2 weeks accompanied by paroxysms of coughing, post-tussive vomiting, and/or inspiratory whooping sound 1, 2
• Critical pitfall: The characteristic "whoop" may be absent in previously vaccinated adolescents and adults, making diagnosis challenging 2
• Pertussis is frequently overlooked in the differential diagnosis of prolonged cough illness, particularly in older patients 1, 2

Laboratory Confirmation

• Obtain nasopharyngeal aspirate or Dacron swab for culture—this is the only definitive diagnostic method 1
• PCR testing is available and increasingly used, though not universally standardized 1, 2
• A confirmed diagnosis requires either positive culture OR compatible clinical picture with epidemiologic linkage to a confirmed case 1, 2
• Paired acute and convalescent sera showing fourfold increase in IgG or IgA antibodies can provide presumptive diagnosis 1

Antibiotic Treatment

First-Line Therapy

Azithromycin is the preferred macrolide due to superior tolerability and compliance compared to erythromycin 3, 4:

• Adults: 500 mg on day 1, then 250 mg daily for 4 days (5-day course) 5
• Children: 10-12 mg/kg/day for 5 days 6, 7

Alternative Macrolides

• Clarithromycin: 500 mg twice daily for 10-14 days in adults 5
• Erythromycin: 500 mg four times daily for 14 days in adults (40-50 mg/kg/day in children) 1, 6

For Macrolide Allergy/Intolerance

• Trimethoprim-sulfamethoxazole: One double-strength tablet twice daily for 14 days 5

Timing and Efficacy

• Most effective when started during the catarrhal stage (first 1-2 weeks) to diminish coughing paroxysms and prevent disease spread 1, 5
• Treatment beyond 3 weeks is unlikely to improve symptoms but still eradicates nasopharyngeal carriage and prevents transmission 1, 5
• Antibiotics do not shorten disease course if started late, but they eliminate contagiousness 3

Isolation Requirements

• Isolate patient for 5 days from start of antibiotic treatment 1, 6
• Without antibiotics, isolation required for 21 days after cough onset 6
• Use standard precautions and surgical mask when within 3 feet of patient 5
• Patient should not attend work or school during the 5-day isolation period 6, 5

Postexposure Prophylaxis for Close Contacts

Who Should Receive Prophylaxis

• All household contacts 5
• Anyone exposed who is at high risk: infants, immunocompromised persons, pregnant women in third trimester 3
• Those in close contact with high-risk individuals 6, 5

Prophylaxis Regimens (Same as Treatment)

• Azithromycin: 500 mg day 1, then 250 mg daily for 4 days 5
• Clarithromycin: 500 mg twice daily for 10-14 days 5
• Erythromycin: 500 mg four times daily for 14 days 5
• TMP-SMX: One double-strength tablet twice daily for 14 days (for macrolide allergy) 5

Therapies NOT Recommended

Do not use the following as they provide no benefit 1:

• Long-acting β-agonists
• Antihistamines
• Corticosteroids
• Pertussis immunoglobulin

Prevention and Vaccination

Children

• Complete DTaP primary vaccination series at 2,4,6,15-18 months, and 4-6 years 1
• Single Tdap booster in early adolescence (11-18 years) 1, 8

Adults

• Single dose Tdap for all adults up to age 65 1
• All pregnant women should receive Tdap between 27-36 weeks' gestation with each pregnancy to convey immunity to newborn 3

Important Vaccination Notes

• Immunity wanes 5-10 years after vaccination or natural infection 1, 2, 5
• "Cocooning" (vaccinating close contacts) is no longer recommended as immunized individuals can still transmit pertussis 3
• History of seizure or hypotonic-hyporesponsive episodes after prior pertussis vaccination is no longer a contraindication 3

Key Clinical Considerations

• Pertussis is highly contagious with secondary attack rate exceeding 80% among susceptible persons 1, 5
• Untreated patients spontaneously clear B. pertussis in 3-4 weeks, but infants may remain culture-positive for >6 weeks 1
• Cough may persist for weeks to months despite appropriate treatment, but patient is no longer contagious after 5 days of antibiotics 6
• Infants <12 months have highest risk for severe complications including apnea, pneumonia, seizures, and death 1, 8