Latent TB carriers are people who carry TB bacteria in an inactive state, do not show signs of illness, have no symptoms, and do not transmit the bacteria to others. People with latent TB infection are at high risk of developing TB disease if their immune system is weakened.

Prevention and treatment of latent tuberculosis is an early preventive measure for healthy people who carry tuberculosis bacteria in their bodies, with the aim of reducing the risk of developing tuberculosis later.

Diagnosis of latent tuberculosis is a measure to help detect early those at risk of tuberculosis, especially those who have had contact with people with pulmonary tuberculosis, to have effective prevention and intervention measures.

Currently, it is estimated that around two billion people worldwide carry Mycobacterium tuberculosis (the bacillus that causes tuberculosis), but most of them have no clinical symptoms. Latent tuberculosis infection (LTBI) is a condition in which the body has an immune response to the antigen, the bacillus that causes tuberculosis in humans, but there are no clinical or paraclinical signs of active tuberculosis.