Remarks

• Serious illness in people living with HIV is defined based on any of the following symptoms:respiratory rate ≥30 breaths per minute, temperature ≥39 °C, heart rate ≥120 beats perminute or unable to walk unaided.
• Advanced HIV disease is defined in people living with HIV who have a CD4 cell count of<200 cells/mm3 or presenting with a WHO Stage 3/4 AIDS-defining illness.
• This concurrent testing recommendation supersedes prior guidance on using LF-LAM forpeople living with HIV and the use of a single molecular test for diagnosis of TB in this group.
• This recommendation is strong despite the low certainty of evidence because the findingsindicate large desirable effects (i.e. rapid and accurate diagnosis of TB in a highly vulnerablepopulation – people living with HIV – in whom diagnosing TB is often challenging) over smallundesirable effects (i.e. negative consequences of this testing strategy).
• The LC-aNAAT products for which eligible data met the class-based performance criteria forthis recommendation were Xpert MTB/RIF Ultra and Truenat MTB Plus. Data for performanceof Truenat MTB Plus and MTB-RIF Dx were only available for testing among persons livingwith HIV without concurrent LF-LAM testing.

Implementation considerations

• 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 diagnostic opportunity and accuracy of case detection, is a more efficient way to address the needs of this population and is preferred even if the testing workload may increase.
• A positive result on either test is sufficient to confirm TB diagnosis.
• Patient loss to follow-up for the second test result should be monitored and prevented. Patients should be provided with 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 rifampicinresistance detection, and is also required when the LF-LAM result is negative.
• Where LF-LAM is not available for testing of people living with HIV, efforts should be made to ensure access to testing.
• LF-LAM does not differentiate Mtb from other mycobacterial species. However, the LAM antigen detected in a clinical sample in TB endemic areas is most likely attributable to Mtb.
• When LF-LAM results are consistently positive, without positive LC-aNAAT results, investigation of the quality of testing and local epidemiology of non-tuberculosis mycobacteria and extrapulmonary TB in the tested population is warranted to understand the difference.
• Interpreting bands on the LF-LAM test strip should be performed using the manufacturer’s reading card to minimize incorrect results.
• LF-LAM test strips must be stored according to the manufacturer’s instructions (e.g. between 2 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 a urine sample to minimize contamination and prevent false positive results.
• Trained staff will be required to perform the LF-LAM test at the point of care.
• As with all WHO-recommended TB diagnostics, quality assurance programmes and quality controls for both tests are required.
• LF-LAM is designed to detect mycobacterial LAM antigen in human urine. Other samples (e.g. sputum, serum, plasma, CSF and other body fluids) or pooled urine specimens should not be used.