Current Diagnosis and Treatment of Pediatric Latent Tuberculosis Infection

Abstract

The goal of diagnosing and treating latent tuberculosis infection (LTBI) in children is to prevent future cases of tuberculosis (TB) disease. In low-prevalence countries, LTBI screening, testing, and treatment are risk based. Testing is limited by lack of a reference standard; both available methods-the tuberculin skin test (TST) and interferon gamma release assays (IGRAs)-have significant limitations. The antigens used in IGRAs are not found in BCG-Mycobacterium bovis or most nontuberculous mycobacteria, making these tests more specific for Mycobacterium tuberculosis infection than the TST. The two methods have similar sensitivity, and neither performs well in immunosuppressed children. Children with LTBI are given treatment because it decreases their risk of developing TB disease, and the rate of significant adverse events is low. The most commonly used treatment regimen of 6-9 months of isoniazid is limited in effectiveness by poor adherence. New treatment regimens, using 4 months of rifampin, 3 months of isoniazid and rifampin, or 12 weekly doses of isoniazid and rifapentine, are safe and have significantly higher completion rates.

Latent tuberculosis may be missed by current screening practices: Analysis of interferon‐gamma release assay results from a paediatric refugee clinic

“…IGRA tests in children are quoted as having a sensitivity of 70–85% for TB infection and specificity of 95% . We acknowledge that some of the positive IGRAs could have been false positives.…”

“…23 IGRA tests in children are quoted as having a sensitivity of 70-85% for TB infection and specificity of 95%. 24 We acknowledge that some of the positive IGRAs could have been false positives. However, it cannot be assumed that each positive IGRA in a child from a country with low TB burden is a false positive.…”