Xpert MTB/RIF on urine samples to increase diagnosis of TB in people living with HIV in Guinea-Bissau

Abstract

Objectives: We investigated if Xpert MTB/RIF (Xpert) testing on urine samples among newly diagnosed HIV-patients as an adjunctive test to Xpert testing on sputum increases diagnosis. We sought to define subgroups of patients, for whom testing with either test is especially advantageous. Methods: We included patients >15 years, newly diagnosed with HIV, that delivered a urine sample on the day of HIV-diagnosis at the biggest HIV-clinic in Guinea-Bissau between September 5, 2016 and October 13, 2017 into a cross-sectional study. Patients were asked for a sputum sample, which was Xpert tested if returned within 30 days. A questionnaire and physical examination were completed on day of inclusion. Results: We included 390 patients. TB prevalence was 12.6%. Adding Xpert urine test to all newly diagnosed HIV-patients increased diagnostic yield of TB by 58% compared with testing on sputum alone. Patients who tested positive by Xpert on urine samples were clinically similar to those tested with sputum, except that the sputum positives reported more cough (p=0.03). Conclusions: Indiscriminate Xpert urine testing in newly diagnosed HIV-patients with advanced disease increased diagnostic yield. Xpert testing for TB on urine and sputum should be offered as screening in Guinea-Bissau and possibly in similar settings.

Keywords

• TB
• HIV
• diagnostic yield
• Xpert
• urine
• Guinea-Bissau