Peripheral clinic versus centralized laboratory-based Xpert MTB/RIF performance: Experience gained from a pragmatic, stepped-wedge trial in Botswana

Tefera Agizew; Rosanna Boyd; Ndwapi Ndwapi; Andrew Auld; Joyce Basotli; Sambayawo Nyirenda; Zegabriel Tedla; Anikie Mathoma; Unami Mathebula; Chawangwa Lesedi; Sherri Pals; Anand Date; Heather Alexander; Thomas Kuebrich; Alyssa Finlay

doi:10.1371/journal.pone.0183237

Peripheral clinic versus centralized laboratory-based Xpert MTB/RIF performance: Experience gained from a pragmatic, stepped-wedge trial in Botswana

PLoS One. 2017 Aug 17;12(8):e0183237. doi: 10.1371/journal.pone.0183237. eCollection 2017.

Authors

Tefera Agizew¹, Rosanna Boyd^{1

2}, Ndwapi Ndwapi³, Andrew Auld⁴, Joyce Basotli¹, Sambayawo Nyirenda¹, Zegabriel Tedla¹, Anikie Mathoma¹, Unami Mathebula¹, Chawangwa Lesedi¹, Sherri Pals⁴, Anand Date⁴, Heather Alexander⁴, Thomas Kuebrich¹, Alyssa Finlay^{1

2}

Affiliations

¹ Center for Disease Control and Prevention, Gaborone, Botswana.
² Division of Tuberculosis Elimination, Center for Disease Control and Prevention, Atlanta, Georgia, United States of America.
³ Ministerial Strategic Office, Ministry of Health, Gaborone, Botswana.
⁴ Division of Global HIV and Tuberculosis, Center for Disease Control and Prevention, Atlanta, Georgia, United States of America.

Abstract

Background: In 2011, the Botswana National Tuberculosis Program adopted World Health Organization guidelines and introduced Xpert MTB/RIF (Xpert) assay to support intensified case finding among people living with HIV enrolling in care. An evaluation was designed to assess performance under operational conditions to inform the national Xpert scale-up.

Methods: Xpert was implemented from August 2012 through November 2014 with 13 GeneXpert instruments (GeneXpert) deployed in a phased approach over nine months: nine centralized laboratory and four point-of-care (POC) peripheral clinics. Clinicians and laboratorians were trained on the four-symptom tuberculosis screening algorithm and Xpert testing. We documented our experience with staff training and GeneXpert performance. Test results were extracted from GeneXpert software; unsuccessful tests were analysed in relation to testing sites and trends over time.

Results: During 276 instrument-months of operation a total of 3,630 tests were performed, of which 3,102 (85%) were successful with interpretable results. Mycobacterium tuberculosis complex was detected for 447 (14%); of these, 36 (8%) were rifampicin resistant. Of all 3,630 Xpert tests, 528 (15%) were unsuccessful; of these 361 (68%) were classified as "error", 119 (23%) as "invalid" and 48 (9%) as "no result". The total number of recorded error codes was 385 and the most common reasons were related to sample processing (211; 55%) followed by power supply (77; 20%) and cartridge/module related (54; 14%). Cumulative incidence of unsuccessful test was similar between POC (17%, 95% CI: 11-25%) and centralized laboratory-based GeneXpert instruments (14%, 95% CI: 11-17%; p = 0.140).

Conclusions: Xpert introduction was successful in the Botswana setting. The incidence of unsuccessful test was similar by GeneXpert location (POC vs. centralized laboratory). However, unsuccessful test incidence (15%) in our settings was higher than previously reported and was mostly related to improper sample processing. Ensuring adequate training among Xpert testing staff is essential to minimize errors.

MeSH terms

Algorithms
Botswana
HIV Infections / complications*
Humans
Laboratories*
Mycobacterium tuberculosis / isolation & purification*
Point-of-Care Systems*
Tuberculosis / complications
Tuberculosis / diagnosis*

Grants and funding

This research has been supported by the President’s Emergency Plan for AIDS Relief (PEPFAR) through the U.S. Centers for Disease Control and Prevention. The funder had no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript.