Prophylactic antitubercular therapy is recommended for which group?

• A. Healthcare workers exposed to TB
• B. People with active TB
• C. Those who have been in close contact with a person with tuberculosis (TB)
• D. People who have received the BCG vaccine

Answer: (C)

Prophylactic therapy after TB exposure targets preventing a latent infection from progressing to active disease. The group at highest risk after exposure are people who have been in close contact with a contagious TB patient, because they’re most likely to have acquired latent TB infection. Treating that latent infection with a preventive regimen (such as isoniazid for several months, or an appropriate rifamycin-based alternative) substantially lowers the chance of developing active TB later.

The other scenarios don’t define the typical target for prophylaxis: healthcare workers who were exposed may need screening and possibly treatment if they test positive or have risk factors, but not automatically prophylaxis for everyone; those with active TB require full treatment rather than preventive therapy; and receiving the BCG vaccine does not dictate the need for prophylactic TB drugs.