Noun
LTBI (plural LTBIs)
Initialism of latent tuberculosis infection: the condition of being infected with tuberculosis but without symptoms of the active disease.
About 90% of those infected with M. tuberculosis have asymptomatic, latent TB infections (sometimes called LTBI), with only a 10% lifetime chance that the latent infection will progress to overt, active tuberculous disease. Source: Internet
Therefore, a positive TST/PPD in a person who has received BCG vaccine is interpreted as latent TB infection (LTBI). Source: Internet