What is the recommended management for individuals exposed to whooping cough (pertussis)?

From the Guidelines

Individuals exposed to whooping cough (pertussis) should receive post-exposure prophylaxis with antibiotics, preferably within 21 days of exposure, to prevent the development of symptomatic infection and reduce the risk of transmission to others, particularly vulnerable populations such as infants, pregnant women, and immunocompromised individuals. The recommended antibiotic is azithromycin, given as 500 mg on day 1, followed by 250 mg daily for days 2-5 for adults, as supported by the 2005 CDC guidelines 1. Children receive weight-based dosing: 10 mg/kg on day 1 (maximum 500 mg) and 5 mg/kg on days 2-5 (maximum 250 mg). Alternative antibiotics include clarithromycin (500 mg twice daily for 7 days for adults; 15 mg/kg/day divided twice daily for 7 days for children) or trimethoprim-sulfamethoxazole (one double-strength tablet twice daily for 14 days for adults; 8 mg/kg/day of trimethoprim component divided twice daily for 14 days for children) 1.

Key Considerations

• Vaccination status should also be assessed, and individuals with incomplete or outdated pertussis vaccination should receive the appropriate vaccine (Tdap for adolescents and adults, DTaP for children) 1.
• Prophylactic antibiotics work by eliminating Bordetella pertussis from the nasopharynx of infected individuals, preventing transmission to others.
• The decision to administer postexposure chemoprophylaxis should be made after considering the infectiousness of the patient, the intensity of the exposure, the potential consequences of severe pertussis in the contact, and possibilities for secondary exposure of persons at high risk from the contact 1.
• The benefits of administering an antimicrobial agent to reduce the risk for pertussis and its complications should be weighed against the potential adverse effects of the drug 1.

Recent Guidelines

A recent study published in 2019 emphasizes the importance of clinically diagnosing pertussis-associated cough in adults and children, and highlights the role of antibiotics in preventing the spread of the disease 1. However, the most recent and highest quality study on postexposure prophylaxis for pertussis is the 2005 CDC guidelines, which recommends the use of azithromycin as the first-line antibiotic for postexposure prophylaxis 1.

From the FDA Drug Label

Erythromycin is effective in eliminating the organism from the nasopharynx of infected individuals, rendering them noninfectious Some clinical studies suggest that erythromycin may be helpful in the prophylaxis of pertussis in exposed susceptible individuals. Although optimal dosage and duration have not been established, doses of erythromycin utilized in reported clinical studies were 40 to 50 mg/kg/day, given in divided doses for 5 to 14 days.

The recommended management for individuals exposed to whooping cough (pertussis) is prophylaxis with erythromycin. The dosage is 40 to 50 mg/kg/day, given in divided doses for 5 to 14 days 2. Key points to consider:

• Erythromycin dosage: 40 to 50 mg/kg/day
• Duration of treatment: 5 to 14 days
• Purpose of treatment: to prevent the development of pertussis in exposed susceptible individuals 2

From the Research

Recommended Management for Individuals Exposed to Whooping Cough (Pertussis)

• The management of individuals exposed to pertussis involves antibiotic prophylaxis to prevent transmission of the disease to others, particularly those at high risk of severe illness 3, 4.
• Household contacts of someone with pertussis and those exposed to pertussis who are at high risk of severe illness (e.g., infants, people who are immunocompromised or in the third trimester of pregnancy) should receive antibiotic prophylaxis 3.
• Azithromycin is the preferred antibiotic for treatment or prophylaxis of pertussis 3.
• The "Identify, Isolate, Inform" (3I) tool can be used to recognize key symptoms of pertussis and risk factors for exposure, and to initiate antimicrobial therapy and post-exposure prophylaxis 4.
• Polymerase chain reaction (PCR) testing is the preferred confirmatory test for diagnosing pertussis, and can be used to detect the presence of Bordetella pertussis in clinical specimens 5, 6, 7.

Vaccination Recommendations

• Patients 11 years or older should receive at least one dose of tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccine 3.
• All pregnant patients should receive Tdap between 27 and 36 weeks' gestation with each pregnancy to convey immunity to the newborn 3.
• Cocooning (vaccinating close contacts of high-risk individuals) is no longer recommended because immunized patients can still contract and transmit pertussis 3.

Diagnostic Testing

• PCR testing can be used to diagnose pertussis in primary care clinics, and can help to optimize diagnosis and treatment, and to break the chain of transmission 5.
• Several PCR methods are available for the detection and differentiation of Bordetella pertussis, Bordetella parapertussis, and Bordetella holmesii, including the Bordetella ELITe MGB Kit, FlexStar® Bordetella PCR Detection Mix, and Vivalytic POCT PCR 7.