Tuberculosis (TB)

Latent tuberculosis infection (LTBI)

Children in front of houses in a fishing village in Jayapura, Papua
WHO/SEARO/Gary Hampton

Latent tuberculosis infection (LTBI) is a state of persistent immune response to stimulation by Mycobacterium tuberculosis antigens without evidence of clinically manifested active TB. A direct measurement tool for M. tuberculosis infection in humans is currently unavailable. One-third of the world’s population is estimated to have LTBI: they do not have active TB disease but may develop it in the near or remote future, a process called “TB reactivation”.

Key topics

Latent Tuberculosis Infection Task Force

WHO has established a Latent Tuberculosis Infection Task Force. The aim is to raise the profile of programmatic management of LTBI particularly in low incidence countries, including monitoring and evaluation of implemented activities, as well as promoting research.

LTBI scale-up

Systematic diagnosis and treatment of LTBI is part of the Post-2015 TB elimination strategy in low incidence countries where the largest proportion of cases derives from reactivation of latent infection.

LTBI research

Further research is currently needed to improve LTBI understanding and management under a clinical and programmatic perspective. The following eight priorities for research in LTBI should be considered by scientific investigators and research funders.

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