TB increases. Care must be taken when using time (with or without antibiotics) to assist in treatment decision making as it can delay the initiation of appropriate treatment. In most instances, a treatment delay for those with TB is not dangerous but caution must be exercised in young children (2 years), those living with HIV, those who are malnourished, and any child with symptoms or signs of EPTB (other than isolated cervical lymphadenopathy). In cases of clinically diagnosed TB, it is important to continue assessing the child with consideration for other diagnoses, even after starting TB treatment. Children with presumed or confirmed TB should be tested for HIV, unless their status is already known. When a decision is made to treat a child for TB, it is also important to evaluate the severity of disease. CXR can help to make this assessment, but even in the absence of CXR, nonsevere disease can be defined as a child who does not have sputum smear-positive microscopy or a high bacillary burden using the Xpert MTB/RIF (or Xpert MTB/RIF Ultra) assay from a respiratory sample, has mild symptoms not requiring hospitalisation and in whom symptoms have completely resolved after 1 month of treatment [27]. Radiology In children and adolescents, CXRs are commonly used to diagnose TB. Anteroposterior films are used in younger (5 years) children and posteroanterior films are used in older children. A lateral image can be of great benefit in visualising hilar lymph nodes. A systematic approach should always be used when interpreting a paediatric CXR (figure 2). CXRs with abnormal findings should be evaluated for the presence of TB-specific features: hilar lymphadenopathy, airways compression, a miliary picture, large pleural effusion and cavities (figure 3). A patient with one of these features is likely to have TB, but their absence does not rule out TB. Abnormal features, such as opacification/consolidation, are consistent with TB as well as with other diseases. CXR can also be used to stratify treatment based on disease severity. Recent revisions to the Diagnostic CXR Atlas for TB in Children provide frontline health workers with valuable guidance [29]. CXRs have been evaluated extensively for adults using artificial intelligence, and the WHO now recommends their use as an alternative to human interpretation for screening and triage for TB in those 15 years of age [30]. There is now increasing work being done in this area for children and younger adolescents, but conclusive performance has not been determined. Lung, mediastinal and focused assessment with sonography for HIV/TB ultrasound imaging has also been explored in the last few years. In some settings where CXR is not available, point-of-care ultrasound may be a useful radiation-free, inexpensive alternative with lower inter-reader variation than CXR [31]. Treatment decision algorithms Treatment decision algorithms (TDAs) have been used for decades to evaluate children with presumptive TB. An assessment of TB disease risk is based on history, examination, FIGURE 1 Algorithm for TBI testing and TPT in children and adolescents. #:including silicosis, dialysis, anti-TNF treatment, preparation for transplantation and other risks in national guidelines. People in this category should also have TB disease ruled out if they have suggestive clinical manifestations. ¶ :if aged 10 years, any one of a current cough, fever, history of contact with TB, reported or confirmed weight loss of 5% since the last visit, growth curve flattening or weight-for-age below −2 Z-scores. Asymptomatic infants aged 1 year living with HIV are treated for TBI only if they are household contacts of a person with TB. A TST or IGRA may identify PLHIV who will benefit most from TPT. CXR may be used in PLHIV on ART before starting TPT. +:any one of cough, fever, night sweats, haemoptysis, weight loss, chest pain, shortness of breath or fatigue. Children aged 5 years should not have anorexia, failure to thrive, not eating well, and decreased activity or playfulness to be considered asymptomatic. § :including acute or chronic hepatitis, peripheral neuropathy (if isoniazid is used) and regular heavy alcohol consumption. Pregnancy and a previous history of TB are not contraindications. ƒ :CXR may have been carried out earlier as part of intensified case finding. ##:regimen chosen based on considerations of age, strain (drug susceptible or otherwise), risk of toxicity, availability and preferences. Reproduced and modified from [27] with permission. https://doi.org/10.1183/2312508X.10025322 215 CHILDREN AND ADOLESCENTS |E. LÓPEZ-VARELA ET AL.