Newborn born to a mother with a positive tuberculin skin test but no evidence of infection should be managed with which approach?

• A. Isoniazid prophylaxis
• B. No pharmacological intervention
• C. Rifampin prophylaxis
• D. BCG vaccination

Answer: (B)

The risk of TB transmission to a newborn is driven by whether the mother has active, contagious TB; latent TB infection in the mother (positive TST without symptoms or radiographic evidence of active disease) does not make the infant contagious. Therefore, no drugs are given to the healthy newborn. The appropriate approach is to monitor the infant and plan follow-up for TB testing as indicated, rather than starting chemoprophylaxis. Isoniazid or rifampin would be reserved for infants with known exposure to active TB or evidence of infection, and BCG vaccination is not routinely used in this scenario. The key idea is that without signs of infection in the newborn and without active maternal disease, prophylactic pharmacotherapy isn’t indicated.