Which of the following is NOT a characteristic of latent TB?

Latent TB infection is a stage of tuberculosis where the bacteria are present in the body but are inactive. Patients with latent TB do not exhibit symptoms, cannot spread the disease to others, and generally do not show signs of active infection.

A positive TST (Tuberculin Skin Test) is characteristic of latent TB, as it indicates that the individual has been exposed to the bacteria. A negative chest X-ray (CXR) is also typical for latent TB, as the lungs appear normal and show no signs of active disease. The absence of signs and symptoms aligns with the definition of latent TB, as individuals do not present any of the active disease manifestations such as a persistent cough, fever, weight loss, or night sweats.

In contrast, being contagious is a hallmark of active TB rather than latent TB. In active TB, the bacteria are multiplying and can be expelled through coughing or sneezing, thus spreading the infection to others. This essential difference clarifies why the correct response highlights that contagious nature is not a characteristic of latent TB.