World Health Organization (WHO) estimates a quarter of the global population is infected with TB.
Latent TB infection (LTBI) is a condition in which a person carries the TB bacteria, but does not have active TB disease and cannot spread it to others. However, if these bacteria become active and multiply, LTBI can turn into TB disease. Preventing TB disease by treating those with latent TB infection is a essential component of the national TB control strategy.
In England a nationally funded programme to systematically provide LTBI testing and treatment for eligible populations was rolled out in 2015. More information about this programme can be found here.