Bibliographic Info
GuidelineWHO guidelines on the management of advanced HIV disease
Year of Publication2025
Issuing InstitutionWorld Health Organization
Recommendation
Status
Maintained
Recommended in favor
Conditional
Certainty of evidence
Low
For children with HIV who have signs or symptoms or screen positive for pulmonary TB, concurrent testing using low-complexity automated nucleic acid amplification tests (NAATs) on respiratory and stool samples and LF-LAM on urine may be used as the initial diagnostic strategy for diagnosing TB, rather than low-complexity automated NAATs on respiratory or stool samples alone
Notes and Remarks
- This recommendation prioritizes concurrent testing over the use of molecular testing andLF-LAM in isolation for diagnosis of TB in children with HIV.• Use of LC-aNAATs on isolated specimens was also evaluated. The findings supported theuse of LC-aNAATs for initial diagnostic testing for TB in HIV-positive children with signs orsymptoms or who screen positive for pulmonary TB, using sputum, gastric aspirate, stool ornasopharyngeal aspirate, rather than smear or culture.• This recommendation is conditional because the findings indicate moderate undesirableeffects (i.e. decreased specificity, resulting in more false positive test results) when comparedwith a single test strategy.• The product for which eligible data met the LC-aNAAT class-based performance criteriafor this recommendation was Xpert MTB/RIF Ultra. The performance of Truenat MTB Plusand MTB-RIF Dx for this recommendation could not be assessed, as data were unavailable. Adults and adolescents living with HIV and children living with HIV
- Global and national HIV and TB programmes need to communicate regularly and clearly, indicating responsibilities for concurrent testing for people living with HIV.
- Concurrent testing maximizes the diagnostic access and accuracy, is a more efficient way to address the needs of people living with HIV and is preferred even if the testing workload may increase.
- A positive result on either test is sufficient to confirm a TB diagnosis.
- Loss to follow-up for the second test result should be monitored and prevented. Patients should be given information to understand the concurrent testing approach and the need for follow-up.
- The LF-LAM performed in point-of-care settings may be the first positive result and is sufficient to make the initial diagnosis. A respiratory sample is still required for detecting rifampicin resistance. It is also required when the LF-LAM is negative.
- Efforts are needed to improve access to LF-LAM.
- LF-LAM does not differentiate Mycobacterium tuberculosis from other mycobacterial species. However, the LAM antigen detected in a clinical sample in TB endemic areas is most likely attributable to Mycobacterium tuberculosis. When LF-LAM is commonly positive without positive low-complexity automated NAATs, further investigation of the quality of testing and local epidemiology of non-TB mycobacteria and extrapulmonary TB in the tested population is warranted to understand the difference.
- Bands on the LF-LAM test strip should be interpreted using the manufacturer’s reading card to minimize incorrect results.
- LF-LAM test strips must be stored according to the manufacturer’s instructions (such as between 2°C and 30°C) in sealed bags and not used after expiration.
- Infrastructure to collect a urine sample privately should be available. Patients should be instructed how to properly and sanitarily collect urine to minimize environmental contamination and prevent false-positive results.
- Trained personnel are required to perform the LF-LAM test at the point of care.
- Similar to all WHO-recommended TB diagnostics, quality assurance programmes for both tests are required.
- LF-LAM is designed to detect mycobacterial LAM antigen in human urine. Other samples (such as sputum, serum, plasma, CSF and other body fluids) or pooled urine specimens should not be used
Also Featured In
This recommendation also appears in the following guidelines:
Originally Developed
Guideline
WHO consolidated guidelines on tuberculosis: module 3: diagnosis
Year2025
InstitutionWorld Health Organization