Children and Adolescents

In children with presumptive PTB attending health care facilities, integrated treatment decision algorithms may be used to diagnose PTB. This is an interim conditional recommendation valid until 2024, after which new evidence will be reviewed (see Box 4.6).

Routine HIV testing should be offered to all children and adolescents completing evaluation for exposure to TB, with presumptive TB or diagnosed with TB. Early and accurate detection of HIV infection is important to support the integrated management of TB/HIV coinfection. All children and adolescents with HIV-associated TB are eligible for ART and co-trimoxazole prophylaxis (6, 78).

CXR remains an important tool in the diagnosis of TB in children, especially those with negative bacteriological tests or where bacteriological testing is not available or not feasible. Most children with PTB have radiographic changes suggestive of TB. If possible, anteroposterior and lateral films should be obtained in children aged under 5 years, and posteroanterior films in older children and adolescents.

Abnormalities on CXR suggestive of PTB include:

Testing for M. tuberculosis infection using TST or IGRA is useful to support a diagnosis of TB in children with suggestive clinical features who are sputum smear-negative or who cannot produce sputum. A positive test for TB infection indicates prior or current infection with M. tuberculosis and can be particularly useful in the absence of known TB exposure (no positive contact history), as it confirms the child has been infected at some point in time (6, 15).

TST is considered positive (indicating infection with M. tuberculosis) if:

In children with signs and symptoms of PTB in settings with a pre-test probability of 5% or higher (prevalence of confirmed TB of 5% or above in this specific population), repeat testing with Xpert MTB/RIF or Ultra may be considered after an initial negative Xpert MTB/RIF or Ultra test if the clinician has a high index of suspicion that the child has TB, using any of the recommended specimen types.

The urine lateral flow lipoarabinomannan (LF-LAM) assay is an immunocapture assay based on the detection of the mycobacterial lipoarabinomannan antigen in urine. For specific populations, LF-LAM may be used together with other approved TB diagnostics tests and affords a distinct advantage as a point-of-care test. Although the assay lacks sensitivity, it can be used as a fast bedside rule-in test for people living with HIV, especially in urgent cases where a rapid TB diagnosis is critical for the person’s survival.

The Xpert MTB/RIF assay is a cartridge-based automated test that uses real-time polymerase chain reaction (PCR) on the GeneXpert® platform to identify M. tuberculosis complex and mutations associated with rifampicin resistance directly from sputum specimens in less than 2 hours (76).

The Xpert MTB/RIF Ultra assay uses the same GeneXpert platform and a new enhanced cartridge developed to improve the sensitivity and reliability of detection of M. tuberculosis complex and rifampicin resistance (76).

Depending on the availability, resources and capacity, appropriate specimens from suspected sites of involvement should be collected for rapid testing using mWRDs or culture, and histopathological examination should be done for children with EPTB whenever possible. WHO recommends that NTPs replace microscopy as the initial diagnostic test for TB with mWRDs, which can be used on various respiratory and non-respiratory specimens (Table 4.4) (76).

WHO-recommended clinical samples for the diagnosis of PTB in children and adolescents using Xpert MTB/RIF or Ultra include sputum (expectorated or induced), gastric or nasopharyngeal aspirates, and stool. Other mWRDs using respiratory samples have only been validated on sputum samples. Each of these specimen types has distinct advantages and disadvantages (Table 4.1). Annex 3 summarizes the types of respiratory and non-respiratory specimens.

Despite challenges with bacteriological confirmation of paucibacillary TB in young children, every effort should be made to establish bacteriological confirmation. In adolescents, who usually have adult-type disease, bacteriological confirmation is common.

Bacteriological confirmation is even more important for children and adolescents who: