For TB infection management, when is a patient typically no longer infectious after starting therapy, and what are the nurse's responsibilities?

• A. Infectiousness remains high after 6 weeks
• B. Infectiousness typically decreases after 2 weeks of effective therapy and smear conversion
• C. Infectiousness is unaffected by therapy
• D. Infectiousness only decreases after 6 months of therapy

Answer: (B)

In TB, how infectious a patient is depends on how many live bacteria are being expelled in the sputum. When effective therapy is started, the bacterial load drops quickly, and the sputum often becomes smear-negative, which is the usual sign that the patient is no longer infectious for transmission—typically after about two weeks of appropriate therapy. The nurse’s responsibilities reflect this timing: ensure the patient takes the medications consistently (often through directly observed therapy), monitor for adverse effects and drug interactions, and perform and document sputum tests to confirm smear conversion. Maintain airborne precautions and isolation until conversion is documented, then follow facility policy to adjust precautions. Provide education to the patient and family about completing therapy (often a six-month course or longer if resistance is present), and coordinate with public health for contact notification and follow-up.