BCSE Practice Exam 2026 – Complete Study Resource

A positive reaction for an HIV-positive individual during a tuberculin skin test (TST) is defined by an induration of greater than 5 mm. However, in the context of the options provided, a greater than 10 mm induration is commonly used as a threshold for individuals in certain high-risk groups.

For HIV-positive individuals, the immune system is compromised, making them more susceptible to tuberculosis infection. Therefore, a smaller amount of induration can indicate a positive result compared to the general population, where thresholds can be higher. Specifically, any induration of 5 mm or more is considered positive in those with a known HIV infection.

While a result greater than 10 mm might be accurate concerning screening standards for those without additional risk factors, the correct understanding is that the definitive marker for positivity in HIV patients is actually lower. In certain clinical practices, the threshold for defining a positive response remains 5 mm for HIV-positive individuals, but since 10 mm is given as an option, it demonstrates a commonly accepted cutoff point used in various healthcare settings when referring to sensitivity in diagnosis.

The choices that suggest higher measurements, such as 15 mm or 20 mm, do not align with the specific context of HIV-infected individuals,