How often should sputum samples be collected to monitor the effectiveness of TB therapy?

• A. Every 2 weeks
• B. Every 8 weeks
• C. Every 4 weeks
• D. Every 6 weeks

Answer: (C)

Monitoring how well TB therapy is working relies on checking sputum for signs of ongoing infection. Collecting sputum samples about every four weeks, i.e., once a month, lines up with typical follow-up visits and gives timely feedback on whether the patient is clearing the bacteria. This cadence balances catching slower responses or potential treatment failure early with the practicality and burden of more frequent testing. Sampling more often than monthly adds little actionable benefit and can be burdensome, while waiting eight weeks or six weeks could delay recognizing slower conversion. So, monthly sputum collection is the standard interval for monitoring treatment effectiveness.