High cost of Xpert MTB/RIF ® testing per tuberculosis case diagnosed at Partners in Hope Medical Center, a public private HIV care clinic in Lilongwe, Malawi. Comparison with fluorescence microscopy in a well- equipped and experienced real world AFB laboratory D. Fitzgerald 1,2, P. Jansen 1, C. Chipungu 1, V. Dindi 1, J. Fielder 1, C. Pfaff 1,2 1 Partners in Hope, Lilongwe, Malawi, 2 University of California, Los Angeles, Program in Global Health, Los Angeles, United States

Background - Malawi Population 15 million HIV prevalence 12-15% TB prevalence 219/ TB patients HIV Positive - 63% Per capita health expenditure $50

Partners in Hope Medical Center Public private clinic HIV patients. TB diagnosis and treatment center AFB microscopy Culture not routinely available

Introduction of Xpert MTB/RIF ® Xpert machine donated Aug 2011 Donation of “near expiration date” cartridges - ability to increase testing of TB suspects

Introduction of Xpert MTB/RIF ® Population: All HIV(+) patients seen at Partners in Hope who were identified as TB suspects Suspicion of possibility TB by experienced clinician based on history and examination Lab: 1 Xpert test and 2 AFB smears Xpert testing - morning samples AFB smears – mixed

Objectives Describe in somewhat ideal real-world setting how to best use Xpert to improve TB case finding Percent of smear (-) sputum samples with (+) Xpert Number of smear (-) sputum samples that need to be tested to yield one (+) Xpert Cost of Xpert testing per smear (-) case detected (using AFB smear as initial test per Malawi draft Xpert guidelines)

Methods Retrospective review of the AFB laboratory records clinical data not collected only included sputum samples

Methods – smear definitions Samples - positive, negative or scanty (<10 AFB/100 HPF) 2007 guidelines – single scanty considered (-) 2012 guidelines – single scanty considered (+) Analysis was done both with single scanty considered (+) and single scanty considered (-)

Xpert Results Patients 417 (+) by Xpert 61 (14.6%) 58 had smear results No sputum was (+) smear and (-) Xpert

Xpert and sputum results 58 positive Xpert that had smear results 35 AFB (+) 60% 15 AFB scanty 26% 8 AFB (-) 14% Increased detection by 16% Increased detection rate by 65% if scanty considered (-)

Numbers of patients needed to be tested with Xpert to detect one case of TB Using protocol of AFB smear first and Xpert if smear “(-)” If scanty considered (-) – 16 patients If scanty considered (+) – 46 patients If Xpert was done on all cases, need to test 8 patients to detect one case

Cost analysis Only based on the price of the cartridge Did not include the cost of the machine, maintenance, lab staff etc.

Cost using Xpert following AFB smear Total smear (-) patients Smear (-) patients with (+) Xpert Number smear (-) patients tested by Xpert to detect one case Cost per test cartridge Cost to detect one smear negative case Scanty smears considered positive $20$920 Scanty smears considered negative $20$320

Conclusions Increased yield over microscopy alone by 16 % - 65% Depends on quality of smear microscopy and guidelines Cost per extra case if using smear as initial screen was quite high ($320-$920) Only possible to replace smear microscopy if costs come down

Caveats of study Retrospective Culture was not done to confirm (-) Xpert tests AFB reader was not always blinded to Xpert result increase number of scanty reads? Mixed patient population Some newly diagnosed ART naive, some already on ART

Acknowledgements Staff and patients at Partners in Hope Lisa Hirschhorn Risa Hoffman Support from PEPFAR/USAID Malawi for clinical operations at Partners in Hope Africa Mission Health Care Foundation