If TB exposure has occurred, how long is the recommended medication course?

If TB exposure has occurred, how long is the recommended medication course?

• A. 6-9 months
• B. 1 week
• C. 12 months
• D. 2 days

Answer: (A)

Preventing progression of TB after exposure requires a lengthy preventive therapy. The standard course is six to nine months of isoniazid. This long duration is needed because TB bacteria can exist in a dormant state and reproduce slowly, so a prolonged treatment increases the likelihood of eradicating them and reducing the chance of reactivation. Short durations like a week or a couple of days are far too brief to clear latent infection. A twelve-month course is longer than what is typically recommended in most guidelines for this scenario, though some regimens have used longer durations in different contexts. The six-to-nine-month regimen remains the commonly tested and accepted duration.

Preventing progression of TB after exposure requires a lengthy preventive therapy. The standard course is six to nine months of isoniazid. This long duration is needed because TB bacteria can exist in a dormant state and reproduce slowly, so a prolonged treatment increases the likelihood of eradicating them and reducing the chance of reactivation.

Short durations like a week or a couple of days are far too brief to clear latent infection. A twelve-month course is longer than what is typically recommended in most guidelines for this scenario, though some regimens have used longer durations in different contexts. The six-to-nine-month regimen remains the commonly tested and accepted duration.