PERFORMANCE OF XPERT MTB/RIF AND DETERMINE LAM IN HIV-INFECTED ADULTS IN PERI-URBAN SITES IN ZAMBIA (CDC OP-X STUDY)

• Published in: BMJ global health 2017-02, Vol.2 (Suppl 2), p.A7-A7
• Main Authors: Kasaro, Margaret Phiri, Muluka, Brenda, Kaunda, Kaunda, Morse, Jill, Westfall, Andrew, Kapata, Nathan, Kruuner, Annika, Henostroza, German, Reid, Stewart
• Format: Article
• Language: English
• Subjects: Diagnostic tests; Global health; HIV; Human immunodeficiency virus; Medical diagnosis; Tuberculosis
• ISSN: 2059-7908; 2059-7908
• DOI: 10.1136/bmjgh-2016-000260.14

BackgroundTuberculosis (TB) mortality in HIV-infected patients remains high in sub-Saharan Africa. Inadequate diagnostic tools delay time to TB treatment.MethodsA two-phase TB diagnostic study was conducted among HIV-infected adult patients from 2014–2016. Patients underwent history/physical exam, chest x-ray, urine for lipoarabinomannan (LAM), sputum smear and culture. We evaluated sensitivity, specificity and time to appropriate treatment within 14 and 28 days of screening for culture-positive patients, comparing Xpert MTB/RIF assay (GXP), and LAM to standard-of-care (SOC) in 3 peri-urban clinics. chi-square and Wilcoxon Rank-Sum tests were used to test for differences between SOC and GXP for categorical variables and continuous variables, respectively.Results1353 patients were enrolled; 755 in the SOC arm and 598 in the GXP arm. Median age was 34.3 and 65.1% were male. TB was diagnosed by any method (smear, clinical, GXP, LAM, culture) in 237 (17.5%) and with positive MTB culture in 152 (11.2%); 84 and 68 in the SOC and GXP arms, respectively. The overall sensitivity and specificity (culture as reference standard) of SOC was 91.7% and 92.9% respectively while GXP was 50.8% and 99.2%, respectively. LAM, when used with SOC, did not improve sensitivity or specificity in any CD4 strata, however when used with GXP increased sensitivity from 20% to 50% at CD4