30 October 2019 | Geneva - The World Health Organization (WHO) has updated its guidance for the use of lateral flow urine lipoarabinomannan assay (LAM) in the diagnosis of tuberculosis (TB). Following new evidence, WHO now recommends a broader use of urinary LAM assays for diagnosis of TB in people living with HIV.
“As we accelerate efforts to reach 40 million people with TB care by 2022 as per the UN high-level meeting political declaration, we need to have more sensitive tools to diagnose TB in all patients, including in those with smear-negative TB, children and people living with HIV”, said Dr Tereza Kasaeva, Director of the WHO Global TB Programme.
Tests based on the detection of mycobacterial LAM antigen in urine have emerged as potential point-of-care tests for TB. The WHO Global TB Programme recommended the use of LF-LAM for the first time in 2015.
Urinary LAM assays have greater sensitivity when used for the diagnosis of TB in people living with HIV. The sensitivity increases significantly in patients with lower CD4 cell counts. Following the new evidence, WHO is recommending LF-LAM use for diagnosis in a broader group of patients, including in adults, adolescents and children living with HIV with signs and symptoms of TB and CD4 cell count under 200 in inpatient settings as well as in adults, adolescents and children living with HIV with signs and symptoms of TB irrespective of the CD4 cell count in outpatient settings.
The WHO End TB Strategy prioritizes early diagnosis of TB. This includes cases of smear-negative disease, which are often associated with HIV coinfection and young age. An estimated 9% (0.9 million ) of the 10.0 million people who developed TB worldwide in 2018 were among people living with HIV. The vast majority of them (71%) are in the WHO African Region.
Source: WHO