Search

BACKGROUND: We conducted the first national TB prevalence survey to provide accurate estimates of bacteriologically confirmed pulmonary TB disease among adults aged ≥15 years in 2014. METHODS: A TB symptoms screen and chest X-ray (CXR) were used to identify presumptive TB cases who submitted two sputum samples for smear microscopy, liquid and solid culture. Bacteriological confirmation included acid-fast bacilli smear positivity confirmed using Xpert ® MTB/RIF and/or culture. Prevalence estimates were calculated using random effects logistic regression with multiple imputations and inverse probability weighting. RESULTS: Of 43,478 eligible participants, 33,736 (78%) were screened; of these 5,820 (17%) presumptive cases were identified. There were 107 (1.9%) bacteriologically confirmed TB cases, of which 23 (21%) were smear-positive. The adjusted prevalences of smear-positive and bacteriologically confirmed TB disease were respectively 82/100,000 population (95% CI 47-118/100,000) and 344/100,000 (95% CI 268-420/100,000), with an overall all-ages, all-forms TB prevalence of 275/100,000 population (95% CI 217-334/100,000). TB prevalence was higher in males, and age groups 35-44 and ≥65 years. CXR identified 93/107 (87%) cases vs. 39/107 (36%) using the symptom screen. CONCLUSION: Zimbabwe TB disease prevalence has decreased relative to prior estimates, possibly due to increased antiretroviral therapy coverage and successful national TB control strategies. Continued investments in TB diagnostics for improved case detection are required.

Introduction: The contribution of high tuberculosis (TB) transmission pockets in propagating area-wide transmission has not been adequately described in Zimbabwe. This study aimed to describe the presence of hotspot transmission of TB cases in Harare city from 2011 to 2012 using geospatial techniques., Methods: Anonymised TB patient data stored in an electronic database at Harare City Health department was analysed using geospatial methods. Confirmed TB cases were mapped using geographic information system (GIS). Global Moran's I and Anselin Local Moran's I (LISA) were used to assess clustering and the local Getis-Ord Gi* was used to estimate hotspot phenomenon of TB cases in Harare City for the period between 2011 and 2012., Results: A total of 12,702 TB cases were accessed and mapped on the Harare City map. In both 2011 and 2012, ninety (90%) of cases were new and had a high human immunodeficiency virus (HIV)/TB co-infection rate of 72% across all suburbs. Tuberculosis prevalence was highest in the Southern district in both 2011 and 2012. There were pockets of spatial distribution of TB prevalence across West South West, Southern, Western, South Western and Eastern health districts. TB hot spot occurrence was restricted to the West South West, parts of South Western, Western health districts. West South West district had an increased peri-urban population with inadequate social services including health facilities. These conditions were conducive for increased intensity of TB occurrence, a probable indication of high transmission especially in the presence of high HIV co-infection., Conclusions and Recommendations: Increased TB transmission was limited to a health district with high informal internal migrants with limited health services in Harare City. To minimise spread of TB into greater Harare, there is need to improve access to TB services in the peri-urban areas., Competing Interests: The authors have declared that no competing interests exist.

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., (Copyright © 2019. Published by Elsevier Ltd.)

Background: Biobanking of Mycobacterium tuberculosis (Mtb) sputum samples for future research activities recommends the use of -70°C or -80°C freezers. Infrastructure for biobanking is not readily available in the majority of low-income countries. This study aimed to assess the recovery rate of Mtb isolates stored at room temperature for more than 6 years in Zimbabwe., Methods: Census samples of all confirmed rifampicin-resistant/multidrug-resistant tuberculosis isolates that were stored in mycobacterial growth indicator tubes (MGITs) at room temperature from 2011 to 2016 were identified and retrieved. The samples were subcultured on MGIT and 7H10 solid media for the extraction of genomic deoxyribonucleic acid using the phenol/chloroform method followed by precipitation with isopropanol., Results: A total of 248/400 (62%) isolates were successfully recovered. Recovery rates increased with declining time since the last culture, with 51% for samples stored for 6 years which increased to 77% for those stored for 1 year. The isolates that grew but were contaminated during the first subculture at the National Microbiology Reference Laboratory in Harare could not be recovered through decontamination because of limited resources. Decontamination was only possible during the second culture at the University of Stellenbosch., Conclusion: Storage of Mtb isolates at room temperature is a viable option in low-income countries where currently recommended biobanking procedures may not be available. This low-cost biobanking will facilitate research activities years later as new questions arise. Standard infection prevention and control when handling Mtb samples stored under room temperature for long periods is strongly recommended as these bacteria remain viable longer than previously reported., Competing Interests: None

Background: Tuberculosis (TB) has remained one of the major public health problems in Zimbabwe with an estimated incidence rate of 552 per 100,000 persons in 2013. The aim of this study was to describe the trends in acid-fast bacilli (AFB) sputum-smear positive (SSP) TB overall and within subpopulations for the period during 2008-2011 in Zimbabwe. Results of this study will contribute towards the evaluation and implementation of targeted TB control interventions., Methods: A cross-sectional study design was used to analyze 40, 110 SSP TB patient records routinely collected during 2008-2011. Incidence trends of SSP TB were described by province, sex, and age group. A Mantel-Haenszel Chi Statistic was calculated to compare each provincial SSP TB notification rate to the national SSP TB notification rate., Results: SSP TB notification rates were higher in the two main urban provinces, the western provinces and Manicaland. The 25-44 year age group accounted for the largest proportion of notified SSP TB. However, the 55-64 year and 65+ age groups had SSP TB notification rates in 2011 higher than the 2008 value. Finally, the average SSP TB notification rate in males was 23% higher than in females., Conclusion: The findings of this study suggest that TB control has successfully decreased the notification rate of SSP TB in Zimbabwe during 2008-2011. However, the disproportionate distribution of SSP TB among different regions and subpopulations of the country highlights the need for more targeted interventions to accelerate the decline of TB in Zimbabwe.

We linked results from the Fourth Botswana National Drug Resistance Survey (DRS), 2007-2008, to patient records from the national Electronic Tuberculosis Registry to determine treatment outcomes. Of 915 new patients, 651 (71%) had treatment data available. Completion or cure was achieved for 10/15 (67%, 95%CI 42-85) with isoniazid monoresistance, (6/16, 38%, 95%CI 18-61) with multidrug resistance, while 73% (391/537, 95%CI 69-76) were susceptible to first-line drugs. The analysis was limited because of unavailable treatment records and undocumented outcomes. Prospective analyses following DRSs should be considered to ensure adequate outcome data.

Setting: Although approximately 0.5 million cases of multidrug-resistant tuberculosis (MDR-TB) occur globally each year, surveillance data are limited. Botswana is one of the few high TB burden countries to have carried out multiple anti-tuberculosis drug resistance surveys (in 1995-1996, 1999 and 2002)., Objective: In 2007-2008, we conducted the fourth national survey of anti-tuberculosis drug resistance in Botswana to assess anti-tuberculosis drug resistance, including trends over time. In the previous survey, 0.8% (95%CI 0.4-1.5) of new patients and 10.4% (95%CI 5.6-17.3) of previously treated patients had MDR-TB., Design: During the survey period, eligible specimens from all new sputum-smear positive TB patients and from all TB patients with history of previous anti-tuberculosis treatment underwent mycobacterial culture and anti-tuberculosis drug susceptibility testing (DST)., Results: Of 924 new TB patients and 137 with previous anti-tuberculosis treatment with DST results, respectively 23 (2.5%, 95%CI 1.6-3.7) and 9 (6.6%, 95%CI 3.3-11.7) had MDR-TB. The proportion of new TB patients with MDR-TB has tripled in Botswana since the previous survey., Conclusion: Combatting drug-resistant TB will require the scale-up of MDR-TB diagnosis and treatment to prevent the transmission of MDR-TB and strengthening of general TB control to prevent the emergence of resistance.