It is estimated that, in 2019, approximately 1.2 million children under 15 years of age fell ill with TB, and 230 000 died of TB (2). In about 56% of the 1.2 million patients, TB was not diagnosed or reported, the proportion being highest in children < 5 years of age (65%). The symptoms of TB are underrecognized in children because they are less specific and overlap with those of common childhood diseases, often leading to delayed diagnosis. Children are more prone to extrapulmonary forms of TB, which may challenge timely detection. Certain forms, especially TB of the central nervous system, carry a high risk of death or permanent disability when detected late, even if treated. Screening children for TB disease is imperative to detect TB earlier, start treatment earlier and increase the likelihood of better treatment outcomes. As children frequently have extrapulmonary TB disease with or without pulmonary involvement, health-care workers must be aware of symptoms that indicate TB at other sites (such as lymphatic, abdominal, meningeal and osteoarticular TB). TB meningitis, disseminated TB and spinal TB are medical emergencies that must be recognized quickly and immediately referred to the appropriate level of care. The risks of severe disease and death from TB can be reduced by BCG vaccination (37, 38); however, the considerations for screening discussed in this section apply regardless of immunization status.
The children who should be targeted for screening are those who are at particularly high risk of TB disease, especially those in close contact with someone with TB and children aged 0–10 years who are living with HIV. Screening of adolescents (10–19 years) living with HIV is discussed in Chapter 5 of this handbook.
Countries are encouraged to monitor and evaluate the yield of TB screening approaches among children to be screened, including child close contacts and children living with HIV, disaggregated by screening tool and algorithm, to broaden the evidence base of the yield, costs, safety and clinical outcomes of different strategies.