What measure is recommended for household contacts of a pertussis patient?

• A. Isolation only
• B. Vaccination only
• C. Macrolide prophylaxis
• D. No treatment

Answer: (C)

After exposure to pertussis, giving antibiotic prophylaxis to household contacts with a macrolide is recommended to prevent illness and curb further transmission. Pertussis spreads easily through droplets, and contacts in the same household are at high risk, especially during the early stages when symptoms may be nonspecific. Macrolides can eradicate nasopharyngeal carriage and reduce the chance that a exposed person will develop pertussis or transmit it to others, even if they are vaccinated or have had pertussis before. Vaccination helps reduce risk and severity but does not provide immediate protection after exposure, so it is not a substitute for post-exposure prophylaxis. Isolation of the patient helps limit spread from the sick individual, but does not protect contacts after exposure. No treatment would leave contacts vulnerable and allow ongoing transmission.