American Board of Internal Medicine (ABIM) Certification Practice Exam

Which test is indicative of bacterial vaginosis?

1. Positive whiff test

2. Positive nitrazine test

3. Positive Chlamydia culture

4. Positive rapid strep test

The correct answer is: Positive whiff test

The positive whiff test is indicative of bacterial vaginosis because it detects the presence of volatile amines that are released when vaginal secretions are mixed with potassium hydroxide (KOH). When a sample is combined with KOH, a fishy odor can be elicited, which is characteristic of bacterial vaginosis and helps differentiate it from other vaginal infections, such as yeast infections or bacterial infections caused by other organisms. The other tests mentioned focus on different conditions. The nitrazine test is primarily used to assess amniotic fluid and is not specific for bacterial vaginosis; it indicates membrane rupture during labor. A positive Chlamydia culture is used to diagnose chlamydial infections, not bacterial vaginosis. Similarly, a positive rapid strep test identifies streptococcal infections, which also does not relate to bacterial vaginosis. Understanding these distinctions highlights why the positive whiff test is specifically relevant in diagnosing bacterial vaginosis.