High cost of Xpert MTB/RIF® testing per

tuberculosis case diagnosed atPartners in Hope Medical Center,

a publicprivate HIV care clinic in

Lilongwe, Malawi. Comparison with fluorescence microscopy in a well-equipped and experienced real world AFB laboratory

D. Fitzgerald1,2, P. Jansen1, C. Chipungu1, V. Dindi1, J. Fielder1, C. Pfaff1,21Partners in Hope, Lilongwe, Malawi, 2University of California, Los Angeles, Program in Global Health, Los Angeles, United States

EQUIP-MALAWI

Background - Malawi

Population 15 millionHIV prevalence 12-

15%TB prevalence

219/100 000TB patients HIV

Positive - 63%Per capita health

expenditure $50

Partners in Hope Medical CenterPublic private clinic

- 4300 HIV patients.

TB diagnosis and treatment centerAFB microscopyCulture not

routinely available

Introduction of Xpert MTB/RIF® Xpert machine donated Aug 2011Donation 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 smearsXpert testing - morning samples AFB smears – mixed

ObjectivesDescribe 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)

MethodsRetrospective review of the

AFB laboratory recordsclinical data not collected only included sputum samples

Methods – smear definitionsSamples - 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 ResultsPatients

417

(+) by Xpert61

(14.6%)

58 had smear results

No sputum was (+) smear and (-) Xpert

Xpert and sputum results58 positive Xpert that had smear results

35 AFB (+)60%

15 AFB scanty26%

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 analysisOnly based on the price of the

cartridgeDid 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

367 8 46 $20 $920

Scanty smears considered negative

382 23 16 $20 $320

ConclusionsIncreased yield over microscopy

alone by 16 % -65% Depends on quality of smear microscopy and

guidelinesCost 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 studyRetrospectiveCulture was not done to confirm (-)

Xpert tests AFB reader was not always blinded

to Xpert result increase number of scanty reads?

Mixed patient populationSome newly diagnosed ART naive,

some already on ART

AcknowledgementsStaff and patients at Partners in HopeLisa HirschhornRisa HoffmanSupport from PEPFAR/USAID Malawi for

clinical operations at Partners in HopeAfrica Mission Health Care Foundation