How has the Zimbabwe mycobacterial culture and drug sensitivity testing system among re-treatment tuberculosis patients functioned during the scale-up of the Xpert MTB/RIF assay?

Background: In Zimbabwe, while the Xpert MTB/RIF assay is being used for diagnosing tuberculosis and rifampicin-resistance, re-treatment tuberculosis (TB) patients are still expected to have culture and drug sensitivity testing (CDST) performed at national reference laboratories for confirmation. The study aim was to document the Xpert MTB/RIF assay scale-up and assess how the CDST system functioned for re-treatment TB patients. Methods: We performed an ecologic study using national aggregate data. Results: Use of the Xpert MTB/RIF assay increased from 11 829 to 68 153 between 2012 and 2016. Xpert assays worked well, with successful tests in more than 90% of cases, TB detection rates at 15-17% and rifampicin resistance in <10%. During Xpert scale-up, the number of sputum specimens from re-treatment TB patients reaching national reference laboratories for CDST increased from 12% to 51%. In terms of laboratory performance, culture contamination increased from 3% to 17%, positive cultures from 13% to 17% and successful CDST from 6% to 14%: the proportion of CDST showing any resistance to rifampicin averaged 44%. From 2009 to 2016, the proportion of notified re-treatment TB patients with successful CDST increased from <1% to 7%. Conclusions: While components of Zimbabwe's CDST system for re-treatment TB patients showed some changes during the scale-up of the Xpert MTB/RIF assay, overall performance was poor. The country must either invest in improving CDST performance or in advanced molecular diagnostic technology

Prevalence of drug-resistant tuberculosis in Zimbabwe: A health facility-based cross-sectional survey.

OBJECTIVE: To determine the prevalence of resistance to rifampicin alone; rifampicin and isoniazid, and second-line anti-TB drugs among sputum smear-positive tuberculosis patients in Zimbabwe. DESIGN: A health facility-based cross-sectional survey. RESULTS: In total, 1114 (87.6%) new and 158 (12.4%) retreatment TB patients were enrolled. MTB was confirmed by Xpert MTB/RIF among 1184 (93%) smear-positive sputum samples. There were 64 samples with Xpert MTB/RIF-determined rifampicin resistance. However, two were rifampicin susceptible on phenotypic drug susceptibility testing. The prevalence of RR-TB was [4.0% (95% CI, 2.9, 5.4%), n=42/1043) and 14.2% (95% CI, 8.9, 21.1%; n=20/141) among new and retreatment patients, respectively. The prevalence of MDR-TB was 2.0% (95% CI, 1.3, 3.1%) and 6.4% (95% CI, 2.4, 10.3%) among new and retreatment TB patients, respectively. Risk factors for RR-TB included prior TB treatment, self-reported HIV infection, travel outside Zimbabwe for ≥one month (univariate), and age <15 years. Having at least a secondary education was protective against RR-TB. CONCLUSION: The prevalence of MDR-TB in Zimbabwe has remained stable since the 1994 subnational survey. However, the prevalence of rifampicin mono-resistance was double that of MDR-TB

Timely Detection of SARS-CoV-2 in Limited Resource Settings: The Role of the Laboratory in Zimbabwe

The recommended approach for response to severe acute respiratory syndrome coronavirus 2, was to test to enable timely detection, isolation and contact tracing so as to reduce the rapid spread of the disease. This highlighted that the laboratory as one of the core capacities of the International Health Regulations and key technical area in the International Health Security was critical in curbing the spread of the virus. Zimbabwe embarked on testing for SARS-CoV-2 in February 2020 following the guidance and support from WHO leveraging the existing testing capacity. Testing was guided by a laboratory pillar which constituted members from different organizations partnering with the Ministry of Health and Child Care. SARS-CoV-2 testing expansion was based on a phased approach using a tiered system in which laboratory staff from lower tiers were seconded to test for coronavirus using RT-PCR with National Microbiology Reference Laboratory (NMRL) being the hub for centralized consolidation of all results. As the pandemic grew nationally, there was an increase in testing per day and reduction in turnaround time as five laboratories were fully capacitated to test using RT-PCR open platforms, thirty-three provincial and district laboratories to test using TB GeneXpert and 5 provincial laboratories to use Abbott platforms

Prevalence, risk factors and treatment outcomes of isoniazid resistant TB in Bulawayo city, Zimbabwe: A cohort study.

INTRODUCTION: The isoniazid-resistant TB poses a threat to TB control efforts. Zimbabwe, one of the high TB burden countries, has not explored the burden of isoniazid resistant TB. Hence among all bacteriologically-confirmed TB patients diagnosed in Bulawayo City during March 2017 and December 2018, we aimed to assess the proportion with isoniazid resistant TB and associated factors. Also, we aimed to describe the TB treatment outcomes. METHODOLOGY: A cohort study involving routinely collected data by the National TB Reference Laboratory (NTBRL) in Bulawayo City and National TB programme of Zimbabwe. The percentage with 95% confidence interval (CI) was used to express the proportion with isoniazid-resistant TB. The modified Poisson regression was used to assess the association of demographic and clinical characteristics with isoniazid mono-resistant TB. RESULTS: Of 2160 bacteriologically-confirmed TB patients, 1612 (74.6%) had their sputum received at the NTBRL and 743 (46.1%) had culture growth. Among those with culture growth, 34 (4.6%, 95% CI: 3.5-6.7) had isoniazid mono-resistant TB, 25 (3.3%, 95% CI: 2.2-4.9) had MDR-TB. Thus, 59 (7.9%, 95% CI: 6.1-10.1) had isoniazid-resistant TB. Children < 15 years had a higher prevalence of isoniazid mono-resistant TB (aPR= 3.93; 95% CI: 1.24-12.45). Among those with rifampicin sensitive TB, patients with isoniazid-sensitive TB had higher favourable treatment outcomes compared to those with isoniazid-resistant TB (86.3% versus 75.5%, p = 0.039). CONCLUSIONS: The prevalence of isoniazid-resistant TB was low compared to neighbouring countries with high burden of TB-HIV. However, Zimbabwe should consider reviewing treatment guidelines for isoniazid mono-resistant TB due to the observed poor treatment outcomes

Prevalance and associated risk factors of multi-drug resistant tuberculosis in adult( 18years and above) HIV positive patients registered at Mpilo OI clinic

Objectives: To determine prevalence of multidrug-resistant tuberculosis (MDR-TB) and associated risk factors among adult (=18 years) HIV positive patients registered at Mpilo Opportunistic Infection (OI) clinic. To assess the association of CD4 count and MDR-TB. Background: Tuberculosis (TB) is a major public health disease, affecting one third of the world’s population and killing approximately two million people yearly. The emergence of resistance to anti -tuberculosis drugs, particularly MDR-TB has become a global threat .Its association with HIV positivity has been reported. It is estimated that approximately 3.6% of all incident TB cases are MDR-TB. In Zimbabwe there are no clear guidelines for MDR-TB case finding in new TB patients. This may lead to mis-treatment as all new TB cases are initiated on first line drugs. Of late Zimbabwe has undergone serious economic hardships which together with its very high burden of HIV could have a negative impact on MDR-TB. Despite the high risk of MDR-TB in HIV positive patients, little has been done to investigate the burden of MDR-TB in these patients. This study determined prevalence of MDR-TB in adult HIV positive patients Methods:A health facility based cross-sectional study was carried out at Mpilo OI Clinic between 01March and 31July 2012. Convenience sampling was used to recruit 275 adult HIV positive patients into the study on a daily basis. A single sample for MDR-TB was collected from each one of these participants. A total of 275 sputum and aspirate(Bone marrow, Aspirates, pus Cerebrospinal fluid) samples were collected and cultured for MDR-TB using both the Liquid using BACTEC Mycobacterium Growth Indicator Tube 960 (MGIT) and the Conventional Solid Lowenstein Jensen (LJ )culture methods. Whole blood for CD4 count was collected from each participant and tested using BD FACS Calibur Flow Cytometry CD4 count machine. Logistic regression was used to determine predictors of MDR-TB prevalence. Results: The prevalence of MDR-TB was 2.6% among adult HIV patients registered at Mpilo OI Clinic and attended the clinic between 01 March and 31July 2012.In the multivariate analysis, MDR-TB prevalence was associated with CD4 count (OR 0.14 p=0.043) Conclusion: A prevalence of 2.6% of MDR-TB among HIV positive patients was found. This is very high considering this high MDR-TB risk group. A CD4 count of >200 cells/ul was found to be protective of high MDR-TB prevalence. Targeted interventions of MDR -TB are necessary to reduce incident MDR-TB cases among HIV positive patients.Increased MDR-TB case finding through culture and Drug Susceptibility testing before initiation of First line drugs is necessary to reduce mistreatment. Infection control measures need to be put in place to reduce transmission of MDR-TB