Investigating gains in TB detection during rollout of Genexpert MTB/Rif universal access to drug susceptibility testing algorithm in Manicaland, Zimbabwe, 2017-2018

Abstract

Objective: To investigate any gains made in Tuberculosis (TB) case detection during Genexpert MTB/Rif universal access to Drug Susceptibility Testing (DST) Algorithm roll out in Manicaland Zimbabwe, 2017 to 2018.

Design:  Retrospective study design.

Setting: The study setting was the eastern province in Zimbabwe called Manicaland which has 304 health facilities served by 15 Genexpert testing sites.

Participants: Total of 36 056 Mycobacterium Tuberculosis (MTB) results generated from 15 Genexpert sites were enrolled.

Interventions:  The intervention was the universal access Genexpert MTB/Rif algorithm rollout. Early TB detection occurs with Genexpert MTB/Rif because it has lower limit of detection compared to less superior smear microscopy, which was replaced as roll out occurred.

Main Outcome Measures: Semi quantitative MTB/Rif test results and the rifampicin resistance pattern.

Results: The study revealed that 5769/36056 (16%) were analysed using targeted MTB diagnostic algorithm versus 30286/36056 (83.7%) analysed using universal access to Drug Susceptibility Testing (DST) MTB diagnostic algorithm. Among the positives the percentage positivity contributed by the semi quantitative measure of between MTB detected trace and MTB detected low was 1043 out of 2222(46.9%), suggesting early TB detection. There was a statistically significant increase in Rifampicin (RR) detection.

Conclusion: As roll out occurred more tests were analysed using the superior diagnostic tool Genexpert MTB/Rif, thus addressing early TB detection. There was statistically significant more rifampicin resistance detected during roll out.