Gates Open Research Open Peer Review RESEARCH ARTICLE The utility of repeat Xpert MTB/RIF testing to diagnose tuberculosis in HIV-positive adults with initial negative result [version 1; peer review: 1 approved, 1 approved with reservations] Yasmeen Hanifa , Katherine L. Fielding , Violet N. Chihota , Lungiswa Adonis , Salome Charalambous , Nicola Foster , Alan Karstaedt , Kerrigan McCarthy , Mark P. Nicol , Nontobeko T. Ndlovu , Edina Sinanovic , Faieza Sahid , Wendy Stevens , Anna Vassall , Gavin J. Churchyard , Alison D. Grant 1,3,12 TB Centre, London School of Hygiene & Tropical Medicine, London, UK The Aurum Institute, Johannesburg, South Africa School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa Mamelodi Hospital, Pretoria, South Africa Health Economics Unit, School of Public Health and Family Medicine, University of Cape Town, Cape Town, South Africa Department of Medicine, Chris Hani Baragwanath Hospital, Johannesburg, South Africa University of the Witwatersrand, Johannesburg, South Africa Division of Medical Microbiology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa National Health Laboratory Service, Johannesburg, South Africa Department of Molecular Medicine and Haematology, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa Advancing Care and Treatment for TB/HIV, South African Medical Research Council Collaborating Centre for HIV and TB, Johannesburg, South Africa Africa Health Research Institute, School of Nursing and Public Health, University of KwaZulu-Natal, Durban, South Africa Abstract Amongst HIV-positive adults in South Africa with initial Background: negative Xpert results, we compared the yield from repeating Xpert MTB/RIF (“Xpert”) on sputum to guideline-recommended investigation for tuberculosis (TB). A systematic sample of adults attending for HIV care were Methods: enrolled in a cohort exploring TB investigation pathways. This substudy was restricted to those at highest risk of TB (CD4<200 cells/mm or unknown) who had a negative initial Xpert result. At attendance for the Xpert result, a repeat sputum sample was stored, and further investigations facilitated per national guidelines. Participants were reviewed monthly, with reinvestigation if indicated, for at least three months, when sputum and blood were cultured for mycobacteria, and the stored sputum tested using Xpert. We defined TB as “confirmed” if Xpert, line probe assay or culture within six months of Mycobacterium tuberculosis enrolment were positive, and “clinical” if TB treatment was started without 1 1 2,3 4 2,3 5 6,7 2 8,9 2 5 6,7 9,10 1 1-3,11 1,3,12 1 2 3 4 5 6 7 8 9 10 11 12 Reviewer Status Invited Reviewers version 1 published 26 Apr 2018 1 2 report report , Johns Hopkins Colleen F. Hanrahan Bloomberg School of Public Health, Baltimore, USA 1 , National University Hospital, Tow Keang Lim Singapore, Singapore 2 26 Apr 2018, :22 ( First published: 2 ) https://doi.org/10.12688/gatesopenres.12815.1 26 Apr 2018, :22 ( Latest published: 2 ) https://doi.org/10.12688/gatesopenres.12815.1 v1 3 Page 1 of 15 Gates Open Research 2018, 2:22 Last updated: 15 MAY 2019