Abstract
SETTING AND OBJECTIVES: Young children living with infectious tuberculosis (TB) cases are at high risk of infection and disease, and screening is recommended. This is rarely conducted in resource-limited settings. Identifying children most at risk of infection may be useful for setting practical screening policies. DESIGN: Child contacts of smear-positive adult TB patients were invited for Mycobacterium tuberculosis infection and disease screening by symptoms, tuberculin skin test (TST), QuantiFERON(R)-TB Gold In-Tube assay (QFT-GIT) and chest X-ray. Risk factors for infection were collected using a questionnaire and were calculated separately for TST, for QFT-GIT and for both tests combined. RESULTS: Of 304 screened children 145/302 (48%) were positive using TST, 152/299 (51%) by QFT-GIT and 180/304 (59%) were positive using either or both tests. Positivity for both tests was associated with index case infectivity (acid-fast bacilli [AFB] 3+ vs. AFB 1+: TST OR 2.93, 95%CI 1.59-5.39; QFT-GIT OR 2.28, 95%CI 1.06-4.90) and exposure (child contact's parent is the index case: TST OR 7.04, 95%CI 2.23-22.28; QFT-GIT OR 4.30, 95%CI 1.48-12.45). CONCLUSION: M. tuberculosis infection according to either test was high, supporting screening and preventive treatment. Children of smear-positive TB cases who accompany their parents to the clinic should be prioritised for immediate screening.
