Diagnosis of Pulmonary Tuberculosis in Children

Abstract

Children account for a major proportion of the global tuberculosis disease burden, especially in endemic areas. Diagnosis of latent tuberculosis infection relies on immunodiagnostic methods, which include the tuberculin skin test and the Interferon-gamma release assays (IGRAs). IGRAs improve specificity in BCG vaccinated children and have been incorporated in several national guidelines especially in low incidence and high-resource settings. However, careful interpretation of this test should be taken especially in young children. Childhood pulmonary tuberculosis is under diagnosed, in part due to difficulties in obtaining microbiological confirmation. Other specimens include induced sputum and nasopharyngeal aspirated that simplify the sample collection without hospital admission. Nucleic amplification assays have similar sensitivity than culture but the results can be obtained in one day. The recent development of an integrated specimen processing and real-time PCR testing (GeneXpert MTB/ RIF system) allows the identification of Mycobacterium tuberculosis and also can detect rifampicin resistance, although additional confirmatory tests of resistance are recommended. Computed tomography (CT) scan is a useful tool in the symptomatic child with difficult diagnosis.