OpiniãoOf the estimated 1.1 million children who developed TB annually, only 399 000 (36.5%) were notified to NTPs in 2020. Under-notification is worst among children below 5 years of age, with only 27.5% of children with TB being notified (1). These 'missing' children are not diagnosed and/or not reported. TB-related mortality among children below 15 years of age was estimated at 226 000 for 2020 (1). Modelling has shown that 80% of TB-related deaths are among children under 5 years of age, and that 96% of children who die of TB, did not access treatment (15).
The low case detection rate among (young) children is due to several factors including: the fact that young children have paucibacillary TB and do not excrete enough bacilli to be detectable by available bacteriological tests; the lack of a sensitive point-of-care diagnostic test; difficulties in collecting suitable respiratory samples for bacteriological confirmation; and misdiagnosis due to the overlap of nonspecific symptoms of TB with other common childhood diseases. Children often first access care at the PHC level, where there may be little or no awareness and capacity to diagnose and manage children with TB (this includes capacity for sample collection, access to bacteriological tests and CXR, as well as capacity and confidence in making a clinical diagnosis when bacteriological testing is not available or is negative). In addition, paediatric TB services are often highly centralized at secondary or tertiary levels of the health system and managed in a vertical, non-integrated way. TB screening is often not systematically incorporated into clinical algorithms for child health (10).
This chapter contains two new recommendations relevant to the diagnosis of TB in children and adolescents as well as other valid WHO recommendations that apply to children and adolescents on TB diagnosis. The two new recommendations relate to the use of the Xpert Ultra assay in gastric aspirate and stool specimens for the diagnosis of PTB and detection of rifampicin resistance among children, and the use of integrated treatment decision algorithms²³ for the diagnosis of PTB in children. Prior to 2022, Xpert Ultra had already been recommended for use in nasopharyngeal aspirate (NPA) and sputum specimens; hence, the 2022 recommendation widens the number of specimens that can be used and aligns this with the WHO recommendation on Xpert MTB/RIF (which WHO recommends for use in gastric aspirate, NPA, sputum and stool specimens to diagnose PTB and detect rifampicin resistance) (16). The two new recommendations are described in detail in this chapter.
Section 4.3 consolidates recommendations from current WHO guidelines on rapid diagnostic tests and the use of commercial serodiagnostic tests, namely the WHO consolidated guidelines on tuberculosis. Module 3: diagnosis - rapid diagnostics for tuberculosis detection, 2021 update (16) and the Commercial serodiagnostic tests for diagnosis of tuberculosis: policy statement (17). For more information on each recommendation including the remarks, source of evidence, justification, subgroup, implementation and monitoring and evaluation considerations, the source guidelines or WHO's TB KSP should be consulted.
The WHO convened an expert consultation on the classification of intrathoracic TB disease among children in September 2021. The experts reviewed evidence from the point of view of pathophysiology, clinical and surveillance, and advised the WHO to update the classification of intrathoracic TB lymphadenopathy in children as PTB.
²³ Treatment decision algorithms are defined as: A flow chart allocating evidence-based scores to microbiological, clinical and radiological features that allow clinicians to make a decision regarding starting TB treatment in children.