Old and new approaches to diagnosing and treating latent tuberculosis in children in low-incidence countries.

PURPOSE OF REVIEW: The primary purpose is to review guidance on the testing and treatment of latent tuberculosis infection (LTBI) in children. Most children and adults with LTBI have positive tuberculin skin test (TST) or interferon gamma release assay (IGRA) results, normal examinations, and normal chest radiographs. Diagnosis of and treatment completion for LTBI are critical to diminish future cases of tuberculosis (TB) disease. RECENT
FINDINGS: Children should be screened for TB risk factors, and only children with risk factors should be tested with either a TST or an IGRA. IGRAs measure interferon gamma production by lymphocytes after they are stimulated ex vivo by antigens that are primarily Mycobacterium tuberculosis-specific. The foundation of LTBI therapy in the United States has been 9 months of daily isoniazid, but shorter treatment regimens now exist, including a 12-dose regimen of weekly isoniazid and rifapentine. These shorter regimens are associated with higher completion rates.
SUMMARY: There are two distinct modalities for LTBI diagnosis and several treatment regimens that can prevent TB disease in infected children. The selection of treatment regimen should take several factors into consideration, including adherence, drug susceptibility results of the presumed source case (if known), safety, cost, and patient preference.