Post-Exposure Prophylaxis for Pertussis

Introduction to PEP

Macrolide antibiotics should be administered as post-exposure prophylaxis (PEP) to close contacts of pertussis cases within 21 days of exposure, with azithromycin being the preferred agent due to better tolerability and shorter treatment duration, as recommended by the Centers for Disease Control and Prevention (CDC) 1, 2

PEP should be administered to close contacts of pertussis cases after considering the infectiousness of the patient, intensity of exposure, potential consequences of severe pertussis in the contact, and risk of secondary transmission to high-risk individuals, according to the CDC 3, 2
The CDC strongly recommends PEP for all household contacts 1, 3
The CDC also recommends PEP for contacts who are at high risk of severe disease, including infants under 12 months, especially those under 4 months 2

The CDC recommends azithromycin as the preferred agent for PEP, with a dosage of 500 mg on day 1, then 250 mg daily for 4 days for adults, and 10 mg/kg on day 1, then 5 mg/kg daily for 4 days for children 1
The CDC also recommends clarithromycin as an alternative agent, with a dosage of 500 mg twice daily for 7 days for adults, and 7.5 mg/kg twice daily for 7 days for children 1

PEP should be administered within 21 days of exposure to be effective, as recommended by the CDC 3, 2
The CDC states that PEP aims to eradicate B. pertussis from the nasopharynx of infected persons (symptomatic or asymptomatic) 4, 1

For infants under 1 month, azithromycin is the preferred agent due to the association between erythromycin and infantile hypertrophic pyloric stenosis, according to the CDC 2
The CDC recommends that pregnant women receive the same antibiotic regimens as non-pregnant adults 2
The CDC suggests that healthcare workers with known pertussis exposure should either receive PEP or be monitored daily for 21 days and treated at symptom onset 5

Pertussis is highly infectious with a secondary attack rate exceeding 80% among susceptible persons, as reported by the CDC 6, 7
The CDC notes that patients with pertussis are most infectious during the catarrhal stage and the first 3 weeks after cough onset 6, 7
The CDC states that antibiotic prophylaxis does not provide long-term protection; vaccination remains the most important preventive strategy 4, 8
The CDC reports that immunity from vaccination wanes after 5-10 years, making previously vaccinated individuals susceptible to infection 7, 8

The Centers for Disease Control and Prevention (CDC) recommends implementing respiratory droplet precautions, including wearing a surgical mask when within 3 feet of a suspected or confirmed pertussis patient, and limiting patient movement and transport to essential purposes only 9
Asymptomatic contacts receiving post-exposure prophylaxis (PEP) can continue normal activities, including work, and routine testing is not recommended; focus on clinical monitoring 9
Healthcare workers who cannot receive PEP should be excluded from caring for children <4 years for 7-14 days post-exposure if mandated by state law 9

The CDC recommends alternative agents, such as clarithromycin or trimethoprim-sulfamethoxazole, for patients with macrolide contraindications, with specific dosing regimens for adults and children 9