The impact of changing the diagnostic algorithm for TB in Manicaland, Zimbabwe.

SETTING: Governmental health facilities performing TB diagnostics in Manicaland, Zimbabwe. OBJECTIVE: To investigate the effect of making Xpert® MTB/RIF the primary TB diagnostic for all patients presenting with presumptive TB on 1) the number of samples investigated for TB, 2) the proportion testing TB-positive, and 3) the proportion of unsuccessful results over time. DESIGN: This retrospective study used data from GeneX-pert downloads, laboratory registers and quality assurance reports between 1 January 2017 and 31 December 2018. RESULTS: The total number of Xpert tests performed in Manicaland increased from 3,967 in the first quarter of 2017 to 7,011 in the last quarter of 2018. Mycobacterium tuberculosis DNA was detected in 4.9-8.6% of the samples investigated using Xpert, with a higher yield in 2017 than in 2018. The overall proportion of unsuccessful Xpert assays due to "no results", errors and invalid results was 6.3%, and highly variable across sites. CONCLUSION: Roll out of more sensitive TB diagnostics does not necessarily result in an increase of microbiologically confirmed TB diagnosis. While the number of samples tested using Xpert increased, the proportion of TB-positive tests decreased. GeneXpert soft- and hardware infrastructure needs to be strengthened to reduce the rate of unsuccessful assays and therefore, costs and staff time

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

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

Comparative Analysis of Genexpert MTB/Rif version 4 and Genexpert MTB/Rif Ultra on Frozen Sputum

Objectives: The aim of this study was to carry out a comparative analysis using Genexpert MTB/Rif Ultra (Ultra) on clinical samples of frozen sputum previously analyzed on Genexpert MTB/Rif version 4 (Xpert)and Mycobacterium Growth Indicator Tube (MGIT) culture.Design: The study employed both retrospective and prospective cross sectional design.Setting: Mutare Provincial Hospital Manicaland, Zimbabwe.Subjects: One hundred and nine de-identified frozen sputum.Interventions: Ultra test.Main Outcome Measures: Ultra results.Results: There was 96/109 (88%) concordance and 10/109 (9.2%) discordance between Xpert and Ultra. Sputum frozen for 7 years then analyzed on Ultra performed better than 7 years previously when it was analyzed as raw sputum on Xpert using MGIT as gold standard (95.6% and 93.2% respectively).The results were comparable and statistically significant, kappa analysis between Xpert and frozen sputum Ultra was not statistically significant showing a slight level of agreement of 0.147 (p value =0.079), 95% CI (-0.1078, 0.4018).Conclusion: Results of Ultra on frozen sputum correlate reasonably well. The study findings show that TB positive frozen sputum from presumptive DRTB, run on Ultra after 7 years freezing can perform better than previously run Xpert results compared to MGIT as gold standard. In light of the research findings, potential implication are that to save on cost, comparison of performance of newly diagnosed tests can be done using frozen sputum, pre run on panel of TB tests

Geo-Spatial Distribution of Frequencies of MTB/RIF Detected Specimens based on Requesting Health Facilities in Manicaland Zimbabwe for 2017 and 2018

Objectives: The aim of this study was to produce Geo Spatial Distribution of Frequencies of MTB/RIF Detected Specimens based on  Requesting Health Facilities in Manicaland Zimbabwe for 2017 and 2018, so as to give insight to TB program managers. Focusing  elimination interventions on hot pockets of Tuberculosis (TB) strengthens rationale use of resources in resource limited countries like Zimbabwe. Early detection and early treatment is backbone of breaking TB transmission. Drug resistant tuberculosis (DRTB) control interventions like Programmatic Management of Drug Resistant TB or mentoring on Short, all Oral Regimen for Rifampicin resistant Tuberculosis (ShORRT) will be driven by science.Materials and Methods: The retrospective study was carried out in Manicaland, Zimbabwe. Manicaland one of the 10 provinces in  Zimbabwe, has 7 districts with 308 health facilities. During this retrospective cross sectional study 2221 MTB detected results of 2017 and 2018, downloaded from 14 of the 15 Genexpert sites in Manicaland were employed to generate hotspot maps. Fifteenth Genexpert site lost its electronic records when Genexpert CPU crushed. Geographical Positioning System (GPS) of the health facilities were recorded. The  study used MTB detected frequencies at a facility in relation to surrounding facilities in Manicaland, then ran optimised hotspot analysis function in Arc Map 10.5 to implement the Gi*statistic.Results: Overall provincial MTB detected positivity was 2221/36055 (6.2%).Overall provincial Rifampicin Resistant (RR) positivity was .111.2221(5.0%).Geo-spatial map of Manicaland showed 10 facilities that are RR hotspots with 7/10 (70%) of the facilities in Buhera district. Chipinge district had facilities that were MTB detected high hotspots.For the whole of Manicaland, Buhera district had100% MTB detected low hotspots facilities. Ninety percent hotspots were clustered around 2 of the 15 Genexpert Sites in Manicaland, namely Murambinda Mission Hospital and Chipinge District Hospital.Conclusion: Study identified health facilities with high frequencies of RR areas. For the identified health facilities with high frequencies of RR specimens, NTP may focus DRTB control interventions like PMDT, or mentoring on ShORRT. For the health facilities with high frequencies of MTB detected NTP can focus trainings in TB Case Management. Instead of uniformly spreading the limited resources to all 325 facilities, efforts streamlined to manageable number of 20 facilities in commensurate with identified gap( e.g. objective selection of cadres for training, data driven supportive supervision & targeted awareness campaigns)