Prevention

WHO guidelines on TPT are premised on the probability that TBI will progress to TB disease in specific risk groups, on the underlying epidemiology and burden of TB and on the feasibility and the public health benefit of the intervention. WHO global policy is expected to provide the basis for the development of national guidelines for PMTPT, adapted to local circumstances. These guidelines envisage a massive extension of TPT, including to individuals exposed to MDR/RR-TB, whereas global coverage of the intervention is still very low, even in priority target groups (10).

Tuberculosis infection (TBI) is defined as a state of persistent immune response to stimulation by M. tuberculosis antigens with no evidence of clinically manifest TB disease (1). As there is no “gold standard” test for TBI, the global burden is not known with certainty; however, about one fourth of the world’s population is estimated to have been infected with M.