Contribution of xpert MTB/RIF assay and Urine LF-LAM for the diagnosis of tuberculosis in children aged 5 - 14 years, at selected health facilities in Ethiopia, 2016 - 2019

Background Childhood tuberculosis (TB) remains under-reported and undiagnosed. A full complement of diagnostic tests is oftentimes unavailable in resource limited country like Ethiopia. This study assesses the contribution of Xpert MTB/RIF assay and urine LF-LAM for childhood TB diagnosis using sputum and urine samples. Method A facility based cross-sectional study was conducted in children between 5 and 14 years of age. Sputum and urine samples were collected from children with presumptive TB. The samples were tested for TB using LF-LAM, Xpert MTB/RIF assay, concentrated smear microscopy, and culture. Diagnostic performance of Xpert MTB/RIF assay was analyzed and compared against culture, which was used as the gold standard. Urine LF-LAM test result was compared to a composite reference standard. Result Of 576 participants with presumptive TB enrolled in the study, 519 (90.1%) had complete clinical data and bacteriological laboratory test results. Active TB was diagnosed in 14.1% (73/519), and bacteriological confirmation was made in 10.1% (52/515) of children with presumptive TB. The odds of being diagnosed with a bacteriologically confirmed TB are significantly higher in children who have household contact history with TB patient (aOR 2.27, P = 0.03) and age above 10 years (aOR 3.67, P Conclusions Pulmonary TB diagnosis was greatly improved with the use of Xpert MTB/RIF assay, particularly in children aged 5-9 years and C/ALHIV who typically have difficulty producing good quality sputum. Urine LF-LAM performed well in children/adolescents who tested positive for HIV, but it performed poorly in the other variables, which suggests that urine LF-LAM testing did not play a critical role in TB diagnosis in children with negative HIV status.