New evidence supports parallel testing strategies to improve TB diagnosis in children and people living with HIV

Parallel testing is crucial for diagnosing TB in vulnerable groups like children. Since they often cannot cough up sputum and require more invasice procedures to get a respiratory sample, it is difficult to apply standard approaches for the diagnosis of pulmonary TB. Combining different tests, for example based on respiratory, stool or urine samples, increases the chances of detecting TB early and accurately.

Cochrane Review CD016070, led by a team around Dr. Laura Olbrich at the Institute of Infectious Diseases and Tropical Medicine at LMU University Hospital Munich in collaboration with international partners, showed that using low-complexity nucleic acid amplification tests (LC-aNAATs) on both respiratory and stool samples increases detection rates in children compared to a single test. Adding a urine lateral flow lipoarabinomannan (LF-LAM) test further improves diagnosis in children living with HIV. The review included 14 studies including 2,145 children to assess parallel testing in children living with HIV and children without HIV. The findings show that the parallel use of LC‐aNAAT on respiratory and stool samples improves the diagnosis of tuberculosis (TB) in these groups.

In the second systematic summary (Cochrane Review CD016071), the researchers searched for studies that had investigated the accuracy of both respiratory LC‐aNAAT and urine LF‐LAM for TB in adults and adolescents living with HIV, and combined the results of these studies. They analyzed 27 studies with 12,651 participants from 19 low- and middle-income countries and found that testing with LC-aNAAT and LF-LAM improves TB detection in people living with HIV but also increases false positives.

Both reviews conclude that parallel testing has the potential to identify more tuberculosis cases in children and people living with HIV, respectively. In areas with low tuberculosis prevalence, it may also result in a higher number of false positives. However, in high-prevalence regions, the benefits of detecting additional true TB cases are likely to outweigh this effect.