Children and Adolescents

Enfants et adolescents
Short Title
Children and Adolescents

4.6 Diagnostic approaches: drug-resistant TB

The clinical presentation of DR-TB in a child or adolescent is similar to that of other forms of TB in a child or adolescent. When DR-TB is suspected, it is important to collect respiratory samples (stool, expectorated or induced sputum, NPA sample or gastric aspirate) for bacteriological confirmation by Xpert MTB/RIF or Xpert Ultra when possible. Truenat MTB or MTB Plus may also be used for sputum specimens. Xpert and

4.4 Diagnostic approaches: extrapulmonary TB

EPTB refers to any bacteriologically confirmed or clinically diagnosed case of TB involving organs other than the lungs (e.g. pleura, peripheral lymph nodes, abdomen, genitourinary tract, skin, joints and bones, meninges) (71). The classification of intrathoracic lymphadenopathy in children was updated following an expert consultation in September 2021 as PTB. EPTB is common in young children and in children and adolescents living with HIV.

4.3.7. Role of chest X-ray

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:

4.3.5.5. Repeat testing with molecular WHO-recommended rapid diagnostic tests

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.

4.3.5.4. Antigen detection in a lateral flow format (biomarker-based detection)

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.

4.3.5.2. WHO-recommended rapid diagnostic tests

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).

4.3.5.1. Sample types

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.

4.3.3. Clinical examination

Although there are no findings on clinical examination that can confirm TB, some clinical signs are highly suggestive. In addition, a variety of nonspecific signs should raise clinical suspicion and prompt an evaluation for TB disease. The following clinical features can alert care providers that the child may have TB (6, 72):