Urine Xpert MTB/RIF for the diagnosis of childhood tuberculosis

Abstract

Introduction: Xpert MTB/RIF is recommended for the simultaneous detection of tuberculosis (TB) and rifampicin resistance directly from sputum specimens. Since young children cannot always expectorate, we assessed urine as a possible specimen source to diagnose TB in children using Xpert MTB/RIF.

Methods: During a field study to enhance childhood TB identification, spot urine samples were prospectively collected from consecutive ambulatory children aged 0 to 14 years presenting with presumptive pulmonary TB in community health centers. Urine Xpert MTB/RIF was performed by blinded technicians in 182 samples using 2ml of unprocessed urine.

Results: The mean age of presumptive TB cases was 5.9 years (median 5.4, range 0.1 to 14.7) with more males (113, 62%) compared to females. All urine samples tested negative for Xpert MTB/RIF, regardless of whether concentration was performed or not. Out of these 182 presumptive TB cases, 50 (28%) were clinically diagnosed and 5 (3%) were bacteriologically diagnosed to have TB disease using either sputum or nasopharyngeal aspirate specimens.

Conclusions: In this community-based study, urine Xpert MTB/RIF does not appear to contribute to the diagnosis of childhood TB.

Keywords: Child; Diagnostic; GeneXpert TB/RIF; Mycobacterium; Pediatric; Philippines.