American Board of Internal Medicine (ABIM) Certification Practice Exam

Which of the following criteria must be met to declare a tuberculosis patient as no longer infectious?

1. One negative sputum smear

2. Improvement of symptoms only

3. Two weeks of treatment and one negative sputum smear

4. Two weeks of treatment, symptom improvement, and three negative sputum smears

The correct answer is: Two weeks of treatment, symptom improvement, and three negative sputum smears

To declare a tuberculosis (TB) patient as no longer infectious, it is essential that a combination of factors is taken into account to ensure both a significant reduction in the bacteria and improvement in the patient's condition. The correct criteria state that there should be two weeks of appropriate treatment, observed symptom improvement, and confirmation through three negative sputum smears. The reason for requiring latent evidence of TB clearance, such as three negative sputum smears, is that this serves as a reliable indicator that the infectious bacteria are no longer present in sufficient quantities to pose a risk to others. Two weeks of treatment is necessary to initiate the killing of the bacteria, while continuous monitoring of symptoms helps confirm that the patient's body is responding positively to the TB medication. This comprehensive assessment minimizes the risk of ongoing transmission and ensures that the patient not only benefits from clinical improvement but also achieves the necessary bacteriological cure indicative of non-infectious status. Other options do not meet the rigorous combination of clinical and microbiological assessments required for making such a determination.