Identification and treatment of children with latent tuberculosis infection (LTBI) has become an important component of tuberculosis (TB) control efforts in low incidence countries such as the United States. The goals of TB screening programs are case finding and treatment of TB disease, prevention of development of disease, and decreased transmission.
Most children with LTBI have been infected recently (especially those younger than age five years). Children and adolescents are at higher risk for progression to TB disease (with potential for disseminated disease) than adults . Most cases of progression to TB disease occur within 2 to 12 months of initial infection . (See "Microbiology and pathogenesis of tuberculosis".)
Issues related to diagnosis and treatment of LTBI in children will be reviewed here. Issues related to treatment of TB disease in children are discussed in detail separately. (See "Tuberculosis disease in children".)
Whom to test — In countries with low incidence and sufficient resources (such as the United States), testing for latent tuberculosis infection (LTBI) in children should be targeted to specific groups at risk for LTBI and/or progression to tuberculosis (TB) disease [3,4]. Only children who would benefit from treatment should be tested, so a decision to test presupposes a decision to treat if the test is positive.
In general, testing for LTBI is warranted to identify individuals who are at risk of new infection, and to identify individuals at increased risk of reactivation due to associated conditions (form 1) [5,6]. Among children, the major risk factor for TB is contact with patients who have TB disease, either due to household exposure or residence in a region where TB is endemic (table 1). A child with a positive tuberculin skin test (TST) should prompt testing of the other siblings in the household. Additional risks include reactivation due to immunosuppressive conditions or medications. A questionnaire developed by the Pediatric Tuberculosis Collaborative Group can be used to screen children in a variety of clinical settings (form 1) .