School of Public Health (ETDs)

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A visual analytics approach to characterising disease progression among adults with chronic diseases in rural Agincourt northeast South Africa
(University of the Witwatersrand, Johannesburg, 2024) Nhlapho, Mapule Dorcus; Kabudula, Chodziwadziwa
Chronic diseases pose a significant challenge to the healthcare systems in South Africa, calling for innovative approaches for comprehensive understanding and management. This research study utilizes the Agincourt HDSS-Clinic dataset to design and implement a visual analytics system using the R Shiny web application framework. Focused on adults with chronic diseases, the tool employs dynamic visualizations to show patterns of healthcare utilization and disease progression. Through the R Shiny platform, the system provides a user-friendly interface for exploring and interpreting complex data, offering valuable insights into patient healthcare behaviours and the dynamics of chronic illnesses. The study used data from a total of 26 426 patients consisting of 19 265 (73%) females and 7 161 (27%) males. The study revealed previously unrecognized associations between specific chronic conditions including the existence of a substantial intersection between HIV, Hypertension, and Diabetes with 101 patients experiencing the coexistence of all the three conditions. Notably, the visual analytics system facilitated the identification of distinct healthcare utilization patterns across different demographic groups highlighting the most frequently visited health facility accounted for 5 912 patient visits overall while the least visited health facility accounted for 1 447 patient visits. The findings underscore the effectiveness of visual analytics in uncovering trends within complex datasets. The implications of these findings extend beyond the immediate research scope, influencing healthcare strategies and contributing to the ongoing discussions on innovative solutions for chronic disease management. This study contributes to the evolving field of visual analytics in healthcare, demonstrating the potential for such tools to inform decision-making and enhance patient outcomes
Assessing the potential interaction between CBD and TBR1 CBD and T-box domain
(University of the Witwatersrand, Johannesburg, 2024) Blignaut, Chanel; Sylvia, Fanucchi; Adeyemi, Samson
In 2020, Cannabidiol (CBD) emerged as the most commonly used recreational substance among pregnant women and was perceived as a natural and safer option for alleviating pregnancy- related symptoms, yet its potential effects on foetal neurodevelopment remain uncertain. With varied results from existing literature on the association between prenatal cannabis use and Autism Spectrum Disorder (ASD) development, this study focuses on filling these knowledge gaps. It investigates the potential interaction of CBD with the T-box domain of TBR1, a transcription factor implicated in ASD. CBD may cross the placenta and distribute throughout the developing foetal organs, including the brain, where it may interact with TBR1. This study's objective is to lay the groundwork for future research into the impact of CBD binding on TBR1 functionality, whose dysregulation is implicated in ASD. The study aims to use in vitro and in silico methods to identify and characterise the interaction between CBD and TBR1 T-box Domain. Initially, predictive models were utilised to determine the structure of the TBR1 T-box domain and its binding domains. Subsequently, the ADMET properties of CBD are assessed to determine its potential interaction with TBR1 T-box domain within the body. Through the optimisation of the TBR1 T-box domain and CBD structures, induced fit docking and molecular dynamics simulations, the study aims to predict the potential interaction sites, dynamics and stability of this interaction. The study confirms the computational results using in vitro methodologies. After expressing and purifying the TBR1 T-box domain, a pull-down assay (PDA), thermal shift assay (TSA) and Time-resolved Fourier-transformed infrared spectroscopy (TR-FTIR) are used to evaluate the potential binding, stability and physiochemical properties of the interaction. Computational analysis, using Maestro Schrödinger Induced Fit Protocol, predicts that CBD binds stably within a hydrophobic pocket of TBR1 T-box domain, away from its DNA-interacting residues. Pose 2 and 3 from molecular docking shows the highest binding affinity and molecular dynamics simulations, using Maestro Schrödinger Desmond Molecular Dynamics System, reveal that the TBR1 T-box domain stabilises upon interaction with CBD. Specifically, the interaction is facilitated by hydrophobic interactions and hydrogen bond formation with residues Ser238, Pro335, Thr360, Glu363 and Asn240. Experimental validation through PDA and TSA provided inconclusive results, but TR-FTIR confirmed the dynamic nature of the CBD-TBR1 interaction, characterised by time-dependent spectral changes. While the results do not directly indicate an impact of CBD on TBR1 functionality, further DNA binding studies are necessary for confirmation. This study suggests caution in using CBD during pregnancy due to its complex and largely unexplored interaction with TBR1, underscoring the need for more comprehensive research to conclusively understand its influence on neurodevelopmental disorders and its therapeutic potential
Association between serum zinc level and dynamics of Group B Streptococcus colonisation among pregnant women in South Africa
(University of the Witwatersrand, Johannesburg, 2024) Dhar, Nisha; Madhi, Shabir A
Background Maternal colonisation by Group B Streptococcus (GBS) is a major risk factor for early onset invasive GBS disease among newborns. Zinc micronutrient plays a critical role in several biological processes that are essential to prevent bacterial colonisation and/or invasion. The aim of this study was to investigate the association of serum zinc levels with GBS rectovaginal new acquisition and clearance from 20 to 37+ weeks gestation in pregnant women. Methods Vaginal and rectal GBS colonisation was determined at 20–25 weeks (visit-1), followed by 3 subsequent visits at 5–6 weeks intervals, until 37–40 weeks gestation (visit-4). Serum was collected at visit-1 and visit-4 and serum zinc was estimated by inductively coupled plasma mass spectrometry. “New acquisition” group was defined as participants for whom GBS culture was negative at visit-1 and acquired GBS in one of the subsequent visits. Participants not colonised with GBS at any visits were categorized as GBS “persistently uncolonised”. Participants who remained colonised throughout all study visits were defined as “persistently colonised” group. GBS “clearance group” included participants who were colonised at enrolment (visit-1) and in whom GBS colonisation cleared by last visit (visit-4). Results Participants in persistently un-colonised group had significantly higher zinc geometric mean concentration (GMC) at visit-1 compared with those who had new acquisition (20.18 µmol/L; 95%CI 17.99-22.64 vs 13.68 µmol/L; 95%CI 12.59-14.87, p=0.03). Higher zinc concentration in the persistently un-colonised group when compared with new acquisition group was significantly associated with lower odds of GBS rectovaginal acquisition [Odds ratio (OR) 0.15, p=0.001]. The lowest zinc threshold significantly associated with 45% lower odds of new acquisition was ≥15 umol/L (27.2% in new acquisition vs 40.5% in persistently un-colonised; OR 0.55; 95%CI 0.31- 0.96; p=0.03). Furthermore, zinc concentration was higher among women in clearance group compared with those in persistently colonised group (20.03 µmol/L; 95%CI 16.54-24.27 vs 16.45 µmol/L; 95%CI 13.32-20.31, p=0.04). Conclusion There was an inverse association between serum zinc levels in pregnant women and odds of GBS acquisition in those not initially colonised. Zinc supplementation in early pregnancy could reduce risk of invasive GBS disease in their newborns
Breast cancer survival to 5 years among young (<40 years) women in the sub-saharan African breast cancer-disparities in outcome (ABC-DO) cohort study
(2024) Abioye, Oyepeju F.
Introduction: Breast cancer remains a key global health challenge, accounting for most prevalent cause of cancer-related deaths worldwide. The impact of age at diagnosis on breast cancer survival has not been extensively investigated within the African context. Therefore, this study’s objectives were to estimate the breast cancer survival time among women 40 years) women in the ABC-DO Cohort Study in SSA. Methods: Secondary data analysis of breast cancer patients from the multi-country ABC-DO Prospective Cohort Study of 5 African countries was carried out. Baseline characteristics of study participants were summarized using descriptive statistics. Kaplan Meier curves were generated to evaluate breast cancer survival time by age group “<40 years, 40-64 years, 65+ years”. With the aid of Cox Multivariate Regression Modelling, factors correlated with a 5-year survival differential between younger and older women were investigated and Hazard Ratios were calculated adjusting for confounders. Results: This study had a total number of 2158 participants, 462 (21.41%) were <40 years at diagnosis, 1314 were between 40-64years (60.89%), while 382 patients were 65 years and above (17.70%). A total of 1211 deaths were recorded at 5 years. The total time at risk and incidence rate at 5 years was 6086.73 person years and 33 per 100 women respectively. The lowest overall survival at 5 years was found among women <40 years (33.46%; CI = 0.28-0.38), followed by women aged 65 years+ (37.63%; CI = 0.32-0.42), and highest overall survival was among women in the 40-64 years age group (42.66%; CI=0.39-0.45). For each country, the 5-year probability of survival was higher among women aged 40-64 compared to women under 40. On Cox multivariate analysis, a 20% rise in mortality was reported among women < 40 years (aHR 1.20; 95% CI= 1.03- 1.36) compared to women between 40-64 years in the final model, at p<0.05. The variables significantly associated with 5-year survival differential between younger and older women were: HIV status, Residence, and Stage at Diagnosis. Conclusion: This study reports that breast cancer survival among women in sub-Saharan Africa is age-specific, with lower 5-year overall and country-specific survival among women < 40 years in comparison to older women. Factors associated with lower survival include stage at diagnosis, HIV status, and area of residence. Young women (<40 years) in SSA remain at risk of increased mortality from breast cancer, hence there is an urgent need for targeted strategies to achieve a more favorable stage at diagnosis and improved survival in this populace.
Cost utility analysis of long acting muscarinic antagonists (LAMAs) as an alternative to long acting beta agonists (labas) for treatment of severe COPD in the South African public sector
(2024) Thompson, Peggy
Objective- The study purposed to estimate the cost-effectiveness of Tiotropium, compared with Salmeterol and Indacaterol for chronic obstructive pulmonary disease (COPD) patients within the South African public sector. Methods- A global Markov model was adapted for the local setting and developed in Microsoft Excel. Transition probabilities and data on costs, resource use and effectiveness were obtained from literature. Outcomes were calculated for 3-years in the base case, then extrapolated over a 10-year and lifetime time horizon. A 5% discounting rate was applied according to local guidelines. Cost-effectiveness was estimated as the incremental cost per quality adjusted life year (QALY). One-way and probabilistic sensitivity analyses were conducted to consider model uncertainty. Results- When compared with Indacaterol (300µg), Tiotropium was dominant (less costly and more effective) across all time horizons. Conversely, Tiotropium was not cost-effective when compared with Indacaterol (150µg) and dominated by Salmeterol over the 3- and 10-year time horizons. The resulting ICURs exceeded the estimated willingness to pay thresholds for all scenarios. The deterministic sensitivity analysis revealed the new intervention cost and utility for mild COPD impacted most on intervention cost effectiveness. Conclusion- Tiotropium was deemed not cost-effective at the proposed price, when compared to usual care for COPD. A price reduction should be considered, to determine the feasibility of displacing existing maintenance therapies. Indacaterol 150µg appeared more cost-effective at the current price and effectiveness demonstrated.
Determinants of mortality in children younger than five years admitted with severe acute malnutrition to three hospitals in Vhembe district, Limpopo
(2024) Fakudze, Dakalo
Background: In 2014, one-third of child deaths occurring in South African hospitals were attributed to severe acute malnutrition. This study sought to determine demographic, family, socio-economic, clinical, and case-management factors contributing to mortality in severely malnourished children younger than 5 years admitted to three hospitals in Vhembe district, Limpopo, South Africa. Methods: A retrospective record review of children aged 6 to 59 months admitted with severe acute malnutrition over 30 months was conducted. Bivariable and multivariable regression analyses of determinants of mortality were undertaken. Results: Two hundred and forty-five children with severe acute malnutrition were identified. Their median (interquartile [IQR]) age was 14 (10, 18) months. The overall mortality was 26.9% (66/245). Determinants of mortality, based on the multivariable analysis, included diarrhoea on presentation (odds ratio [OR]=3.34, 95% CI 1.38, 8.10); anaemia (OR=3.30, 95% CI 1.28, 8.50]); a raised CRP (OR=9.29, 95% CI 2.81, 30.76]); and hyponatraemia (OR=6.64, 95% CI 2.70, 16.31). HIV status and a diagnosis of shock were not significant determinants of mortality. Conclusion: Severe acute malnutrition mortality was high, particularly for a high middle-income country setting. Factors that may be amenable to intervention include better management of the presenting illness, particularly diarrhea, a focus on electrolyte imbalance correction, and treatment of anemia.
Determinants of sub-optimal glycaemic control among patients enrolled in a medicine dispensing programme in Kwazulu-Natal: A cohort study, 2018 – 2021
(University of the Witwatersrand, Johannesburg, 2023) Johnston, Leigh Clare
Background: In South Africa, type 2 diabetes mellitus (T2DM) is a growing public health problem, thus, by 2030, 50% of T2DM patients, receiving treatment, must achieve optimal glycaemic control (haemoglobin A1c (HbA1c) ≤7%). The CCMDD (Central Chronic Medicines Dispensing and Distribution) programme allows glycaemically-stable patients to collect their medication from community-based pick-up points. While the CCMDD is a large public health programme, there is a paucity in stakeholder’s knowledge of T2DM patients glycaemic control over time. We determined glycaemic control for CCMDD-enrolled T2DM patients in eThekwini, South Africa from 2018-2021, as well as the rate and predictors of becoming sub-optimally controlled. Methods: We performed a cohort study, linking HbA1c data from the National Health Laboratory Service to CCMDD-enrolled patients in eThekwini, South Africa from 2018–2021. We included patients optimally controlled at their baseline HbA1c, and having ≥1 repeat test available. We used Kaplan Meier analysis to assess survival rates and Cox regression to determine associations between time to sub-optimal control (HbA1c > 7%) and several factors. Adjusted hazard ratios (aHR), 95% confidence interval (95% CI), and p-values are reported. Results: Of 41145 T2DM patients enrolled in the CCMDD, 7960 (19%) had an available HbA1c result over the study period. A quarter of patients (2147/7960; 27%) were optimally controlled at their baseline HbA1c. Of those controlled at baseline, 695 (32%) patients had a repeat test available, with 35% (242/695) changing their status to sub-optimal control. Patients prescribed dual-therapy had a higher risk of sub-optimal glycaemic control (aHR: 1.503; 95% CI: 1.16–1.95; p-value=0.002) compared to those on monotherapy. HbA1c testing frequency per national guidelines (aHR: 0.46; 95% CI: 0.24–0.91; p-value=0.024) was associated with a lower hazard of sub-optimal glycaemic control. Conclusions: HbA1c monitoring, in line with testing frequency guidelines, is needed to flag sub- optimally controlled patients who become ineligible for CCMDD enrolment. Patients receiving dual-therapy may require special consideration. Addressing these shortfalls can assist planning and implementation to achieve 2030 targets.
Early life factors associated with childhood trajectories of violence among the birth to twenty- plus cohort in Soweto, South Africa
(University of the Witwatersrand, Johannesburg, 2024) Muchai, Lilian Njeri; Kagura, Juliana; Naicker, Sara
Introduction Violence against children has devastating and long-term negative consequences on individuals' and society's health, social and economic well-being. There is limited research on the life course experience of violence especially in Africa. This study aimed to identify sub-groups of physical & sexual violence victimization patterns separately in childhood, and evaluate early life factors predicting these violence trajectories. Methods This study used data from age 5 to 18 years from the ongoing prospective Birth to Twenty Plus cohort (Bt20+). Children within the Bt20+ cohort with data on physical and sexual violence in at least 2-time points between 5 and 18 years were included in the analyses. Group-based trajectory modelling was employed to identify groups of children with similar patterns of violence over time. Descriptive statistics was used to summarize study variables by violence trajectory group membership, while multivariable logistic regression was used to identify early life factors measured between birth and 5 years, associated with violence trajectory group membership. Results Two trajectory groups were identified for both physical and sexual violence victimization. For physical violence victimization, the majority of participants fell into the adolescent limited group (65.1%) and just over a third (34.9%) of the children were in the chronic increasing group. For sexual violence victimization, most participants fell into the adolescent limited group (74.1%, with a quarter in the late increasing (25.9%) group. Early life factors associated with a higher risk of chronic increasing physical violence victimization trajectory group membership, after adjusting for covariates, were being male (aOR 1.67, 95% CI 1.31; 2.10) and having a mother with at least secondary education compared to higher education (aOR 1.73, 95% CI 1.08; 2.76). In addition, residing in middle, compared to low, socioeconomic households (aOR 0.68, 95% CI 0.50; 0.92) was protective against membership in this group. Residing in high compared to low socioeconomic households, was the only early life factor with marginally significant (aOR 0.63, 95% CI 0.42; 0.95) association with membership in the late-increasing sexual violence victimization trajectory group, with those in better-off households less likely to experience sexual violence victimization with this pattern. Conclusion Children within the same community can follow different patterns of both physical and sexual violence victimization across childhood. Identification of early factors that predict membership to sub-groups of violence trajectories provides key violence prevention intervention points that can preempt or mitigate children’s exposure or experience of violence. Future research should explore a larger variety of early life factors proximal to the child as well as those more distal at the community and school levels
Efficacy of water suppression method for controlling the emissions of submicron particles at a quarry, Boksburg, South Africa
(2024) Mkwanazi, D. D.
Background: Respiratory diseases has contributed 70% to worldwide occupational disease mortality in all industrial sectors since over a decade ago. Pneumoconioses occur as a result of accumulation of dust in the lungs. Silicosis, one of the most common forms of pneumoconioses, presents in three different forms namely acute, accelerated, and chronic silicosis. Quarrying and open cast mining are responsible for different workplace hazards including noise, trauma, vibration, ultraviolet radiation, and dust exposure, which may cause silicosis. Lung deposition of particulate matter depend on the particulate matter surface characteristics, aerodynamic size, and weight. Quarrying and stone crushing activities are associated with high levels of crystalline silica release. Water suppression has been proven to effectively control dust in mining and construction industries, but not enough attention has been paid on effects of water suppression on fine particulate matter. Purpose: To evaluate efficacy of water suppression as a dust control measure for submicron particles for the primary, secondary and tertiary treatment processes during the production of stone aggregates in a quarry. Methods: In this cross-sectional study data was collected using a Nanozen dust sampling device to monitor dust emissions in 0.300µm to 10.658µm bin sizes across 4 different sampling points namely primary, secondary, tertiary treatment area, and office complex at a quarry in Boksburg, South Africa. In the primary treatment area big rocks are crushed into 150mm smaller rock without dust suppression, the secondary area breaks them further into 57mm stones with water supperssion applied, and tertiary breaks them into 19mm and smaller stone products under further water suppression conditions. Primary treatment area and office complex were sampled as dry areas, while secondary and tertiary treatment areas were sampled as water suppression areas. Data was analysed based on mass and number concentrations for different bin sizes, and comparisons were made between dry and wet areas. The effect of water treatment (suppression) on submicron bin ranges (0.300-0.915µm) in terms of mass concentration and number concentration was analysed to determine its efficacy in reducing dust emissions in this range. Results: The total average mass concentration of 460.2 µg/m3 (±486.3) was emitted from the primary area without dust suppression with average of 2.22E+08 (±136958.7) number concentration. This was reduced to 6.02µg/m3 and 60.9 million (±552879) mass and number concentration respectively in secondary treatment area with water suppression. In tertiary area emissions were 10.52µg/m3 and 54.8 million particles/cm3 (±828126) respectively for mass and number concentrations following further water suppression, while in office area (no water suppression) 6.07µg/m3 and 44.4 million/cm3 mass and number concentrations were recorded respectively. Conclusions & Recommendations: Data showed reduction of emissions between primary and secondary area by 98.7% (mass concentration) and 72.5% (number concentration). Further treatment in tertiary treatment showed a further decrease in total average number concentration compared to secondary treatment. Emissions at the office block as a control site were consistent with emissions from secondary and tertiary treatment areas, demonstrating possible dispersion by wind. Water suppression was demonstrated to be effective against particle bin sizes larger than 1 micron, with progressively less effect on submicron particles as they became smaller. More research is recommended on suppression of submicron dust particulate matter emission and consideration of number concentration as a key dose matrix to determine exposure.
Estimating and predicting HIV risk using statistical and machine learning methods: a case study using the 2005 to 2015 Zimbabwe demographic health survey data
(2024) Makota, Rutendo Beauty Birri
Background: The 90–90–90 targets were launched by the Joint United Nations Programme on HIV/AIDS (UNAIDS) and partners with the aim to diagnose 90% of all HIV-positive persons, provide antiretroviral therapy (ART) for 90% of those diagnosed, and achieve viral suppression for 90% of those treated by 2020. In Zimbabwe, a population-based survey in 2016 reported that 74.2% of people living with HIV (PLHIV) aged 15–64 years knew their HIV status. Among the PLHIV who knew their status, 86.8% self-reported current use of Antiretroviral treatment (ART), with 86.5% of those who self-reported being virally suppressed. For these 90–90–90 targets to be met, prevalence and incidence rate estimates are crucial in understanding the current status of the HIV epidemic and determining whether the trends are improving to achieve the 2030 target. Ultimately, this will contribute to the achievement of Sustainable Development Goals 3 (SDG 3) and the broader goal of promoting sustainable development and eradicating poverty worldwide by 2030. Using data from household surveys, this thesis provides a unique statistical approach for estimating the incidence and prevalence of the Human Immunodeficiency Virus (HIV). To properly assess the efficacy of focused public health interventions and to appropriately forecast the HIV-related burden placed on healthcare systems, a comprehensive assessment of HIV incidence is essential. Targeting certain age groups with a high risk of infection is necessary to increase the effectiveness of public health interventions. To jointly estimate age-and-timedependent HIV incidence and diagnosis rates, the methodological focus of this thesis was on developing a comprehensive statistical framework for age-dependent HIV incidence estimates. Additionally, the risk of HIV infection was also evaluated using interval censoring methods and machine learning. Finally, geospatial modelling techniques were also utilised to determine the spatial patterns of HIV incidence at district levels and identify hot spots for HIV risk to guide policy. The main aim of this thesis was to estimate and predict HIV risk using statistical and machine learning methods. Study objectives: The study objectives of this thesis were: 1. To determine the effect of several drivers/factors of HIV infection on survival time over a decade in Zimbabwe, using current status data. 2. To determine common risk factors of HIV positivity in Zimbabwe and the prediction capability of machine learning models. 3. To estimate HIV incidence using the catalytic and Farrington models and to test the validity of these estimates at the national and sub-national levels. 4. To estimate the age- and time-dependent prevalence and HIV Force-of-infection (FOI) using current status data by comparing parametric, semi-parametric and non-parametric models; and determining which models best fit the data. 5. To investigate the HIV incidence hotspots in Zimbabwe by using geographicallyweighted regression. Methods: We performed secondary data analysis on cross-sectional data collected from the Zimbabwe Demographic Health Survey (ZDHS) from 2005 to 2015. Datasets from three Zimbabwe Demographic Health Survey HIV test results and adult interviews were merged, and records without an HIV test result were excluded from the analysis. The outcome variable was HIV status. Survey and cluster-adjusted logistic regression were used to determine variables for use in survival analysis with HIV status as the outcome variable. Covariates found significant in the logistic regression were used in survival analysis to determine the factors associated with HIV infection over the ten years. The data for the survival analysis was modelled assuming age at survey imputation (Model 1) and interval-censoring (Model 2). To determine the risk of HIV infection using machine learning methods, the prediction model was fit by adopting 80% of the data for learning/training and 20% for testing/prediction. Resampling was done using the stratified 5-fold cross-validation procedure repeatedly. The best algorithm was the one with the highest F1 score, which was then used to identify individuals with a higher likelihood of HIV infection. Considering that the proportion of those HIV negative and positive was imbalance with a ratio of 4.2:1, we applied resampling methods to handle the class imbalance. We performed the Synthetic Minority Over-sampling Technique (SMOTE) to balance the classes. We evaluated two alternative methods for predicting HIV incidence in Zimbabwe between 2005 and 2015. We estimated HIV incidence from seroprevalence data using the catalytic and Farrington-2-parameter models. These models were validated at the micro and macro levels using community-based cohort incidence and empirical estimates from UNAIDS EPP/SPECTRUM, respectively. To ascertain the age-time effects of HIV risk, we estimated the age- and time-dependent HIV FOI using current status data. Five generalised additive models were explored, ranging from linear, semi-parametric, non-parametric and nonproportional hazards additive models. The Akaike Information Criteria was used to select the best model. The best model was then used to estimate the age- and time-dependent HIV prevalence and force-of-infection. The OLS model was fitted for each survey year to determine the global relationship between HIV incidence and the significant covariates. The Moran's I spatial autocorrelation method was used to assess the spatial independence of residuals. The Getis-Ord Gi* statistic was used for Hotspot Analysis, which identifies statistically significant hot and cold spots using a set of weighted features. Interpolation maps of HIV incidence were created using Empirical Bayesian Kriging to produce smooth surfaces of HIV incidence for visualisation and data generation at the district level. The Multiscale Geographically Weighted Regression method was used to see if the relationship between HIV incidence and covariates varied by district. The software used in the thesis analysis included R software, STATA, Python, ArcGIS and WinBugs. Results: Model goodness of fit test based on the Cox-Snell residuals against the cumulative hazard indicated that the model with interval censoring was the best. On the contrary, the Akaike Information Criterion (AIC) indicated that the normal survival model was the best. Factors associated with a high risk of HIV infection were being female, the number of sexual partners, and having had an STI in the past year prior to the survey. The machine learning model indicated that the XGBoost model had better performance compared to the other 5 models for both the original data and SMOTE processed data. Identical variablesfor both sexes throughout the three survey years for predicting HIV status were: total lifetime number of sex partners, cohabitation duration (grouped), number of household members, age of household head, times away from home in last 12 months, beating justified and religion. The two most influential variable for both males and females were total lifetime number of sex partners and cohabitation duration (grouped). According to these findings, the catalytic model estimated a higher HIV incidence rate than the Farrington model. Compared to cohort estimates, the estimates were within the observed 95% confidence interval, with 88% and 75% agreement for the catalytic and Farrington models, respectively. The limits of agreement observed in the Bland-Altman plot were narrow for all plots, indicating that our model estimates were comparable to cohort estimates. Compared to UNAIDS estimates, the catalytic model predicted a progressive increase in HIV incidence for males throughout all survey years. Without a doubt, HIV incidence declined with each subsequent survey year for all models. Based on birth year cohort-specific prevalence, the female HIV prevalence peaks at approximately 29 years of age and then declines. Between 15 and 30 years, males have a lower cohort-specific prevalence than females. Male cohort-specific prevalence decreases marginally between ages 33 and 39, then peaks at age 40. In all age categories, the cohort-specific FOI is greater in females than males. Moreover, the cohortspecific HIV FOI peaked at age 22 for females and age 40 for males. A 18-year age gap between the male and female HIV FOI peaks was observed. Throughout the decade covered by this study, the Tsholotsho district remained a 99 % confidence hotspot. The impact of STI, condom use and being married on HIV incidence has been strong in the Eastern parts of Zimbabwe with Mashonaland Central, Mashonaland East and Manicaland provinces. From our findings from the Multiscale Geographically Weighted Regression (MGWR), we observed that Matabeleland North’s HIV incidence rates are driven by wealth index, multiple sex partners, STI and females with older partners. Conclusions: The difference between the results from the Cox-Snell residuals graphical method and the model estimates and AIC value may be due to inadequate methods to test the goodness-of-fit of interval-censored data. We concluded that Model 2 with interval-censoring gave better estimates due to its consistency with the published results from the literature. Even though we consider the interval-censoring model as the superior model with regard to our specific data, the method had its own set of limitations. Programmes targeted at HIV testing could use the machine learning approach to identify high-risk individuals. In addition to other risk reduction techniques, machine learning may aid in identifying those who might require Pre-exposure prophylaxis. Based on our results, older men and younger women resembled patterns of higher HIV prevalence and force-of-infection than younger men and older women. This could be an indication of age-disparate sexual relationships. Therefore, HIV prevention programmes should be targeted more at younger females and older males. Lastly, to improve programmatic and policy decisions in the national HIV response, we recommend the triangulation of multiple methods for incidence estimation and interpretation of results. Multiple estimating approaches should be considered to reduce uncertainty in the estimations from various models. The study spread the message that various factors differ from district to district and over time. The study's findings could be useful to policymakersin terms of resource allocation in the context of public health programs. The findings of this study also highlight the importance of focusing on districts like Tsholotsho, which have consistently had a high HIV burden over time. The main strength of this study is dependent on the quality of the data obtained from the surveys. These data were derived from population-based surveys, which provide more reliable and robust data. Another strength of this study was that we did not restrict our analysis to one method; however, we had the opportunity to determine the risk and incidence of HIV by exploring different methodologies. However, the limited number of variables accessible to us for this study constituted one of its drawbacks. We could not determine the impact of variables including viral load, health care spending, HIV- risk groups, and other HIV-related interventions. Additionally, there were missing values in the data, which required making assumptions about their unpredictability and utilising imputation methods that are inherently flawed. Last but not least, a number of the variables were self-reported and, as a result, were vulnerable to recall bias and social desirability bias.
Evaluation of implementation fidelity to national guidelines on management of tuberculosis in paediatric patients in Homa-Bay County, Kenya
(2022) Kiptoon, Sharon Cherono
Background: Tuberculosis (TB) has been a major public health concern for a long time. Infection in children has not been given a lot of focus as in adults despite children being a vulnerable population with weaker immunity. Prognosis is worse when there is HIV/TB coinfection. The WHO rolled out guidelines for the management of TB in pediatric patients which were adopted by the Kenya Government. Health care workers then implement the guidelines. The Objectives of this study were to measure adherence to national guidelines on the management of Tuberculosis in Pediatric patients (up to 14 years) and to identify moderators affecting implementation fidelity. Methods: A convergent parallel mixed method design was used to collect information from TB treatment sites in Homa bay County. The study was conducted during the months of August, September and October 2018.Quantitative data collected focused on Pediatric patients between ages zero and 14. A checklist based on the guidelines was designed to review 442 records in the clinics for a four-year period (2014 to 2018). Qualitative data was collected through in-depth interviews with eight Sub-County TB coordinators. Interview moderators were based on Carrol et al Implementation Fidelity framework. Summation of "yes" and "No" responses were tallied to get an adherence score for the County as a whole and for the sub-counties individually. The qualitative analysis used the thematic method in excel spreadsheets. Results: Results showed high adherence for the County with a median of 80% (IQR 66.66-93.33%). Four of the sub-counties with normally distributed scored had a mean score of 79% and while the other four had a median score of 80% (66.66 – 93.33). Guidelines which had low implementation fidelity scores were those involving follow up tests i.e., sputum, gene X-pert and X-ray during duration of treatment. In the qualitative aspect good facilitation strategies were found to be in place from both the County and national TB programs. An attitude of fear, lack of knowledge on infection prevention, lack of skills to produce specimens for TB testing and staff shortages affected quality of treatment delivery. The health care workers reported ease in following the guidelines especially with the roll out of new guidelines which simplified diagnosis of TB in children, drugs which are dispersible and in fixed dose combination. Participant’s response to the intervention was poor with both health care workers and patients expressing difficulties with direct observed therapy schedule which required frequent visits and frequent follow up tests. Conclusion and recommendations: In conclusion, implementation fidelity to guidelines on management of tuberculosis is high. Good facilitation strategies is a positive moderator towards achieving high implementation fidelity. The national TB program in Kenya is doing well so far in monitoring the process of guideline implementation once rolled out, however, to be able to achieve the sustainable development goal eradicating TB, further follow up is needed in the facilities to improve the levels of adherence from 80% to 100%. Use of the conceptual framework by Carroll has proved to be a good guide in evaluating healthcare worker’s performance in implementing treatment guidelines It is recommended that health workers should undergo more sensitization on why certain guidelines have been put in place e.g., repeating sputum samples at different phases of treatment in order to improve quality of care. More training on vital procedures e.g., gastric aspirate should also be done to improve health workers' confidence and ease diagnosis of TB at younger age. Further research on implementation fidelity on other evidence based interventions would go a long way to improve service delivery and ensure other program goals are met.
Exploring healthcare user perspectives on utilisation of prevention of mother to child transmission (PMTCT) services in a high-mobility context in Johannesburg, South Africa
(2024) Bisnauth, Melanie Ann
Included in this thesis are four original papers. The first of four papers explored the impact of the Option B+ Prevention of Mother to Child Transmission (PMTCT) of human immunodeficiency virus (HIV) programme on the work of healthcare professionals and, investigated pregnant women living with HIV (WLWH) experiences with antiretroviral therapy (ART) for life, to gain insights in ways to better manage the programme. The first paper (Chapter 6) explored the views of both healthcare providers and user experiences with ART for life at the time the SA’s National Department of Health (NDoH) adopted World Health Organisation (WHO) 2013 guidelines on ARVs for HIV treatment and prevention in 2015. This included changes to PMTCT through Option B+ (now known as lifelong treatment). In 2015, little was known about the impact of these guidelines on the work of healthcare workers (HCWs) and no research at the time had focused on how these changes have affected adherence for the patients. Semistructured interviews were conducted with participants and revealed that work had become difficult to manage for all HCWs because of the need to strengthen indicators for tracking patients to decrease the PMTCT loss to follow-up (LTFU); there was inconsistency in delivery of counselling and support services and a need for communication across clinical departments of the hospital that both offered PMTCT services and had to provide care to the mothers and; a lack of compassion and understanding was existent amongst service providers. The overburdened healthcare environment had affected the overall views and experiences of pregnant WLWH going on ART for life. All patient participants (n=55) responded that they chose the fixed dose combination (FDC) pill for life to protect the health of the baby and felt ART for life could be stopped after giving birth, unaware of the long-term benefits for the mother. Although SA national women were interviewed at the time, RMMCH had provided PMTCT care to many migrants and their experiences needed to be heard. Further research was needed on how to strengthen the programme for long term scalability and sustainability for highly mobile WLWH to better adapt PMTCT programming within the healthcare system. Observations of the population of women accessing PMTCT at RMMCH indicated that many migrant WLWH were utilising the services and called for further investigation and lead into the next two phases of the research study. In addition, Paper 2 (Chapter 7) and Paper 3 (Chapter 8) data collection occurred during the COVID19 pandemic. Paper 2 (Chapter 7) investigated HCWs and their experiences in the provision of PMTCT services to WLWH, specifically migrants that were utilising services during the SARS-CoV-2 (COVID-19) pandemic in SA, to provide further insights on the programme. The COVID-19 pandemic resulted in SA taking preventative and precautionary measures to control the spread of infection, this inevitably proposed challenges to WLWH, especially migrant women by limiting population mobility with border closures and lockdown restrictions. Semi-structured interviews (n=12) conducted with healthcare iii providers across city, provincial, and national levels explored how COVID-19 impacted the healthcare system and affected highly mobile patients’ adherence and utilisation of PMTCT services. Findings revealed; a need for multi-month dispensing (MMD); fear of contracting COVID-19 leading to the disruption in the continuum of care; added stress to the already existent overburdened clinical environment; mistreatment and xenophobic attitudes towards the migrant HIV population and; three key areas for strengthening PMTCT programme sustainability for migrants. Paper 3 (Chapter 8) investigated the insights of migrant WLWH. Migrant typologies were not predetermined a priori. This research allowed for the different mobility typologies of migrant women utilising PMTCT services in a high mobility context of Johannesburg to first surface from the data. By analysing these experiences, it explored further into how belonging to a specific typology may have affected the health care received and their overall experience during the COVID-19 pandemic. Interviews with cross-border migrants (n=22) (individuals who move from one country to another) and internal migrants (n=18) (individuals who transcend borders within a country) revealed that women in cross-border migration patterns compared to interprovincial/intraregional mobility; expressed more fear to utilise services due to xenophobic attitudes from HCWs; were unable to receive ART interrupting adherence due to border closures and; relied on short message service (SMS) reminders to adhere to ART during the pandemic. All 40 women struggled to understand the importance of adherence due to the lack of infrastructure to properly educate them following social distancing protocols. COVID-19 amplified existing challenges for cross-border migrant women to utilise PMTCT services. Future pandemic preparedness should be addressed with differentiated service delivery (DSD) including MMD of ARVs, virtual educational care, and language sensitive information, responsive to the needs of mobile women and to assist in alleviating the burden on the healthcare system. The pandemics’ impact on the study timeline, key lessons learnt and, take away messages when conducting research during this unpredictable time are provided in Chapter 4 (Methods) and Chapter 9 (Discussion). It is important to include these reflections because of the impact it had on all participants and the entire PhD process. Paper 4 will be a future policy piece, drawn from Chapter 9, addressing the need for responsiveness from the SA government and NDoH. Chapter 9 brought together collectively the previous papers 1,2, and 3 and drew overall conclusions, recommendations, and a way forward for both policy and programme implementation. This chapter provided the principal findings of the overall thesis and in relation to other studies in the field, as well as implication for policy practice and research. Chapter 9 concludes with the recommendations for future research on WLWH, mobility typologies, service provision of PMTCT and future pandemic preparedness, and the vision for the South African PMTCT programme.
Exposure and risk assessment of benzene, toluene, ethyl benzene and xylene (btex) in a petrochemical depot at Heidelberg, South Africa
(2022) Mdlalose, Richard John
Background: The International Labour Organization estimated 2.2 million workers are dying yearly from work-related accidents and occupational diseases, whilst about 270 million suffer serious injuries, and 160 million become ill due to their work. It is further estimated that work-related accidents and diseases cause 4% of annual Global Gross Domestic Product or US $1.25 trillion due to lost working time, workers’ compensation, the interruption of production, and medical expenses. In 2005, the ILO estimated that 440 000 people died throughout the world because of exposure to hazardous chemicals. In 2018 chemicals production was the second largest production sector in the world. Chemicals are indispensable and critical part of life. Their visible positive outcomes are quite palpable. They are well recognized for instance pesticides improve the quality of food production, pharmaceuticals cure illness, cleaning products help to establish hygienic living conditions. Chemicals are key development of final products that make life little easy for human beings, etc. Controlling employees ‘exposure to chemicals and preventing or minimizing emissions remains a significant challenge in workplaces throughout the world. The production, storage, and handling of petrochemical products particularly BTEX emissions are known and associated with potential harm to human and aquatic organisms. Some of the health effects associated with exposure to BTEX are the health effects on hematopoietic system, including pancytopenia. The benzene exposure leads to an acute myelogenous leukemia. The exposure to toluene, ethylbenzene, and xylene have been linked to the damaging the central nervous system and irritation of the respiratory system. Benzene and ethylbenzene are confirmed carcinogens (Benzene is classified as a Group 1 and ethylbenzene is a Group 2 B carcinogens). Purpose: To characterize, assess exposure and health risk assessment to benzene, toluene, ethylbenzene, and xylene (BTEX) at the petrochemical depot at Heidelberg in Gauteng, South Africa. Methods: Exposure sampling was done using a MiniRAE 3000 Photoionization detector (PID). The PID (equipment) was calibrated before the commencement of the monitoring program following the manufacturer’s operating manual. The PID equipment was used to collect the BTEX samples. The PID was mounted on a marked tripod stand at 1.5 m above ground and approximately 0.2 m to 0.5 m in the microenvironment (Exposure scenario) of the depot workers (Controllers and/or laboratory assistant) with the probe extended or placed within 30cm of the breathing zone of the depot workers. Sampling was conducted at three different exposure scenarios (workstations) i.e., density huts, laboratory, and during plant equipment cleaning in the plant (strainer removal) over three days period. The sampling started from 08h00 to 17h00. One workstation was sampled per day. The sampling of BTEX per workstation took 30 minutes per hour over ten hours, every hour BTEX was sampled for a duration of 30 minutes and in totality ten samples were collected per 12- hour shift, a total of 30 BTEX samples were collected over the 3 days period. Additionally, the measured BTEX concentrations were used to obtain dose estimates. Data from the equipment was exported to a Microsoft Excel spreadsheet. All outliners were removed from the data and a correction factor was applied to derive the final concentration. Thereafter, statistical tests using student F-test and Test were performed to evaluate for significant differences amongst paired comparisons. Results : The highest average BTEX concentrations were measured in the laboratory, followed by density huts and the least was measured during the removal of the strainer (plant equipment cleaning). The activity areas (exposure scenarios) served as direct sources for the BTEX vapours. The average benzene concentrations measured in three activity areas ranged from 469 ppm to 542 ppm. The highest benzene concentration was found to be 542 times higher than the current South African Occupational Exposure Limits of 1ppm. The average toluene concentrations measured ranged from 1335 pm to 1542 pm; the highest toluene concentration was found to be more than 30 times above the South African Occupational Exposure Limits of 50 ppm. The average ethylbenzene concentrations measured ranged from 433 ppm to 500 ppm; the highest concentration was found to be 5 times above the South African Occupational Exposure Limits of 100 ppm. The average xylene concentrations measured ranged from 1372 ppm to 1584 ppm, the highest concentration was found to be more than 15 times above the South African Occupational Exposure Limits of 100 ppm. All the measured BTEX compounds were found to be above their respective South African Occupational Exposure Limits. The cancer risk was determined to be 13 x 10-2 (male) and 10 x 10-2 (female), 14 x 10-2 (male) and 11x 10-2 (female), 16 x 10-2 (male) and 13 x 10-2 (female), 12 x 10-3 (male) and 10 x 10-3 (female) for the workers in the density huts, laboratory, strain remover (plant equipment cleaning), respectively. In all exposure scenarios (male and female) the cancer risk was found to be higher than the acceptable risk levels of 1E-4 . There were 13 males and 10 females in the population of 100 controllers who were likely to develop cancer when working density huts environment. In the laboratory work environment, 14 males and 11 females in a population of 100 controllers were likely to develop cancer, whereas 16 males and 13 female laboratory workers were likely to develop cancer in a population of 100 laboratory workers, and during plant equipment cleaning 12 males and 10 female controllers were likely to develop cancer in a population of 1000. Therefore, the potential of developing cancer was heightened by working in the laboratory and density huts. The risk of the number of employees who were likely to develop cancer was reduced when doing plant equipment cleaning. In all three activity areas, cancer risk for males was higher than for their female counterparts. This finding denotes that male were more vulnerable than females even though the exposure concentration is the same. The higher number of males who were likely to develop cancer in all the activity areas were influenced by two factors i.e., males have a shorter average life expectancy and higher average body weight versus their females’ counterparts. A hazard quotient was used to determine the non-carcinogenic health effects, a hazard quotient of greater than 1 was used as a reference value. A value greater than 1 denoted a higher possibility that depot workers will get health effects from exposure to the Toluene, ethylbenzene, and xylene (TEX). The hazard quotient for males ranged from 4.6 to 577.5, the highest hazard quotient was more than 577 times above the HQ reference value. The lowest was at density huts for xylene and the highest was at the laboratory for a chemist for xylene. The hazard quotient for females ranged from 3.15 to 399.00, the highest hazard quotient was more than 399 times above the HQ reference value. The lowest was at density for xylene and the highest was at the laboratory for laboratory assistant. From the results, both males and females had a hazard quotient far above 1 which means health effects arising from TEX exposure were anticipated. Conclusion: The results showed highest constant BTEX concentrations in the three exposure scenarios over the 12 hours shift. The BTEX emissions were generated by activities that were performed by the depot workers. Highest BTEX concentrations were measured at laboratory, followed by density huts and the least was measured during the removal of the strainer (plant equipment cleaning). The lack of effective vapour recovery system and natural ventilation in the laboratory and in density huts also contributed to the high BTEX concentrations measured in these areas. Individual BTEX component results measured in the three activity areas indicated concentrations that were far above the South African Occupational Exposure Limits for individual BTEX. The cancer risk score was found to be far above the reference USEPA cancer risk value and denoting that depot workers were likely to develop cancer. The hazard quotient for the three exposure scenarios was also found to be greater than the reference value of 1 which indicates the potential to develop non-carcinogenic health effects due to exposure in three exposure scenarios. Recommendations: The following recommendations are made to assist management of the depot to control employees’ exposure to BTEX emissions per activity area: Density huts: The practicality of introducing a vapour recovery system on workbenches to extract the VOCs generated during sample collection and from density measuring jugs should be investigated or alternatively, the introduction of an online fuels and density analysis should be investigated or the practicality of introducing sample bombs to collect fuel samples should be investigated. Keep the windows opened to promote an ingress of fresh air and allow BTEX emissions to escape. A practicality of introducing a controlled mechanical ventilation to blow vapours away from the breathing zone of the depot workers should be investigated. Laboratory: The practicality of automating or modifying the GC equipment in the laboratory to be able to conduct an online petrochemical analysis to control employees’ exposure should be investigated. The tasks that require rinsing of testing tubes with fuels, refilling of the testing tubes, and discarding of superfluous samples should be performed under controlled conditions, the practicality of introducing a vapour recovering system to control vapours emissions should be investigated. The current practice of keeping the decanting drum open should be discontinued to prevent the accumulation of vapours in the laboratory or alternatively, it should be kept under a vapour recovery system. The practicality of keeping the retained fuel samples under the vapour recovery system in the laboratory storage should also be investigated. The fume hood and two extraction units should be serviced on a regular basis. Cleaning of plant equipment (strainer removal): The practicality of automating the removal and lifting the strainer to be cleaned to increase the distance between the strainer and receptors (controllers) should be investigated. The practicality of putting the clogged-up strainer in degreaser bath to remove and clean the strainer with the view of automating the task to prevent employees ‘exposure to VOC emissions. Recommendations applicable to all activity areas: Employees exposed to BTEX including the other petrochemicals should undergo a risk-based medical surveillance program including biological monitoring to evaluate the efficacy of the existing controls and as part of a preventative medical surveillance program. Provide information, instruction, and training at regular interval about: - petrochemicals (BTEX) that employees are potentially exposed to at workplace and duties of persons who are likely to be exposed to VOCs vapour. The names and potential harmfulness of the BTEX at the workplace and the employees who are likely to be exposed. Significant findings of the BTEX exposure assessment (an occupational health risk assessment survey). Information on how to access the relevant safety data sheets and information that each part of an SDS provides. The work practices and procedures that must be followed for the use, handling, storage, transportation, spillage, and disposal of samples, in emergency situations, as well as for good housekeeping and personal hygiene. The necessity of personal exposure air sampling, biological monitoring, and medical surveillance; The need for engineering controls and how to use and maintain them. The need for personal protective equipment, including respiratory protective equipment, and its use and maintenance. The precautions that must be taken by an employee to protect themselves against health risks associated with exposure, including wearing and using protective clothing and respiratory protective equipment. The necessity, correct use equipment, maintenance and potential of safety facilities and engineering control measures provided. Supervisor/Line Manager must give written instructions of the procedures to be followed in the event of spillages, leakages, or any similar emergency situations to employees. Once the aforementioned information, instruction and training have been provided, enforce the wearing of the prescribed PPE including ABEK respirator and no employee should be allowed to enter and remain in respiratory zone without the prescribed PPE and respiratory protection equipment (ABEK respirator).
Facilitators and barriers influencing implementation of interventions to eliminate silicosis in the South African mining industry
(2024) Patrick, Chinyelu Josephine
Background Silicosis is an occupational disease that affects workers, their life, livelihoods, families and communities. Poor workers’ health and wellness impact negatively on company efficiency, productivity and profits leading to major economic losses to the whole society. Silicosis is an added burden to the health service in South Africa. The disease is caused by exposure to respirable crystalline silica (RCS) dust. In the South African mining industry, there is an increased risk of tuberculosis among mineworkers exposed to RCS dust and those who develop silicosis. Silicosis is incurable but preventable and RCS dust control is the key. Extensive efforts have been deployed globally and nationally toward the elimination of silicosis. In South Africa, the mining industry set milestones for RCS dust reduction and silicosis elimination by 2013, now extended to 2024. The National Programme for the Elimination of Silicosis in South Africa has only been partially successful due to poor implementation of interventions, the complexity of interventions, and non-compliance with enacted policies. This may account for the fact that novice, current and former mineworkers are still being diagnosed with silicosis in the country. This study aimed to describe the existing implementation strategies and explore the facilitators and barriers to implementation of silicosis elimination interventions in the mining industry, South Africa. Methods A cross-sectional exploratory qualitative study was conducted using in-depth interviews among 18 participants selected purposively based on knowledge and experience in the mining industry. The Consolidated Framework for Implementation Research (CFIR) guided the development of the interview guides, data collection and analysis. Framework analysis was conducted and the transcribed data were coded using a hybrid of inductive and deductive coding to derive themes and sub-themes. Results 18 participants consisting of representatives from DMRE, Minerals Council South Africa, MHSC, MOSH, mining companies, unions and an academic researcher were interviewed. The five main themes identified in this study were intervention-related factors, implementation related factors, human-related factors, health-related factors and contextual factors. The strategies identified in the study were found to be part of the facilitators for implementation. The facilitators identified in the study were technological advancement, communication and dissemination of strategies, the Minerals Council’s role, industry milestones, legislation, enforcement of regulations, monitoring and evaluation, and compensation benefits. The major barriers were the lack of implementation practices and inadequate enforcement. Conclusion In the study, CFIR framework was used to guide a systematic process that looked at the strengths and weaknesses of silicosis elimination in the larger mines under the leadership of the Minerals Council South Africa. A lot of work has been done in terms of communication, legislation, enforcement, provision of interventions and efforts from all stakeholders. There a is need to improve communication and feedback with mineworkers on the message of silica dust reduction, enforcement of legislation and policies.
Factors associated with burnout among healthcare workers in a rural context, South Africa: a cross-sectional study
(2024) Moses, Alexandra
Background. Healthcare providers (HCP) were at risk of burnout related to high levels of occupational stress in the workplace. However, there was little research in rural and primary care settings in subSaharan Africa. This study aimed to describe the individual and workplace factors of public sector HCP working in Mpumalanga province, their experience of burnout and to examine the factors associated with burnout.. Methods. A quantitative study design using a cross-sectional survey was employed. The research site was Nkomazi Local Municipality in Mpumalanga Province. All HCPs (n=1 139) working at the primary healthcare clinics, community health centres and district hospitals were invited to participate in the survey. Data were collected between April and September 2022 via a selfadministered, electronic questionnaire. A demographic and occupational questionnaire, the General Help Seeking Questionnaire and the Health and Safety Executive (HSE) indicator tool were used to assess individual and workplace factors. Burnout was assessed using the Maslach Burnout Inventory– Human Services Survey. Univariate and multivariate regression analyses were used to examine factors associated with burnout. Results. Just over a quarter (n=302; 26.5%) of HCP participated. Participants were aged between 23 and 61 years, mostly female (n=252; 83.44%) and nurses (n=235; 77.81%). Most participants (n=215; 71.19%) would seek help if they had an emotional problem, most likely from mental health professionals, and least likely from traditional healers. Increased work-related stress was present due to the demands and roles of HCP. High levels of burnout were observed for Emotional Exhaustion (Median score 26 (IQR: 18)) and Personal Accomplishment (median score 29 (IQR: 9)) but not for Depersonalisation (median score 7 (IQR: 9)). On univariate regression analysis, the individual factor of being married and the workplace factor of increased years of experience were statistically significant to all three subscales of burnout. HSE factors of demands, control, management support, peer support, relationships, role and change were highly statistically significant to Emotional Exhaustion, Depersonalisation and Personal Accomplishment. On multivariate regression analysis, no individual demographic, occupational or HSE factors were significantly associated with Emotional Exhaustion or Depersonalisation. Personal Accomplishment ii improved by 0.49 (95%CI: 0.10-0.89) for every one point increase towards improved work demands, by 0.84 (95%CI: 0.01-1.67) for every point score increase towards improved management support, and by 1.19 (95%CI: 0.48-1.90) for every point score increase towards having improved role. Conclusions. During 2022, HCPs working in a rural area in South Africa displayed high levels of burnout for Emotional Exhaustion and Personal Accomplishment but not for Depersonalisation. Improvements in work demands, managerial support and role were significantly associated with an increase in the experience of Personal Accomplishment. Further research is recommended to better understand the nuances of the work environment. Solutions should be explored and implemented to prevent burnout, with special consideration given to work demands, managerial support and role clarity as part of the effort to retain rural HCP in the public health system.
Factors associated with extreme nonadherence to tb treatment among adult defaulters attending Gqeberha clinic between 2018 and 2019
(University of the Witwatersrand, Johannesburg, 2024) Chipise, Elisha; Kagura, Juliana; Tshuma, Ndumiso
Background Tuberculosis remains a significant public health problem in sub-Saharan Africa leading to high morbidity, mortality, social and economic implications. Tuberculosis is a curable condition that can be eliminated. However, global efforts towards ending TB are under threat from patients’ nonadherence to effective TB treatment. This study aimed to determine the prevalence and factors associated with extreme nonadherence to TB treatment among adult defaulters attending Gqeberha clinic in South Africa. Methods The study is a secondary data analysis of a cross sectional study on TB defaulters attending Gqeberha clinic. The analysis included 144 participants with minimum age of 18 years who had defaulted treatment between April 2018 and September 2019. TB nonadherence and study characteristics were described using frequencies and percentages. Extreme nonadherence was defined by an aggregate score of at least 4 based on the Morisky Medication Adherence 8-item scale (MMA8). The prevalence of extreme nonadherence was estimated using percentage frequencies while univariable and multivariable logistic regression modelling were performed to identify the factors associated with extreme nonadherence. Results There were 18(12.9%) TB defaulters who had extreme nonadherence. The majority of TB defaulters 65.2% (n=90) were men. All participants involved had a minimum age of 18 years. 73.4% (n =102) of the study participants stayed in formal dwellings, 79.1% (n =110) were unemployed, 68.8% (n =95) had not attained matric level qualification and 78.4% (n =109) were either single, divorced or separated. A larger proportion of participants, 79.9% (n =111) stayed within 5km radius of Gqeberha clinic, 65.5% (n =91) experienced shorter waiting times and 84.2% (n =117) acknowledged constant availability of medicines at the health facility. However, 69.1% (n =96) did not have a family member who encouraged them to attend clinic visits, 64% (n =89) lacked adequate food whilst taking medication, and 80.6% (n=112) had inadequate income to cover their basic needs whilst on treatment. After adjusting for covariates, those who took other medication besides TB treatment had 0.33 times odds (95% CI: 0.11-0.97) of extreme nonadherence compared to their contrasting peers. All the other factors were not significant in the adjusted model. Conclusion The prevalence of extreme nonadherence to TB treatment among adult defaulters was low. The participants involved in the study were from low-income families with the majority being unemployed, having low educational attainment and lacking adequate food during treatment course. The use of multiple drugs was significantly associated with lower odds of extreme nonadherence. There is need to intensify programs aimed at improving adherence to treatment if the end TB by 2035 goal is to be realized.
Factors associated with vector control for onchocerciasis control in sub-Saharan Africa (2000 – 2023) : a systematic review
(University of the Witwatersrand, Johannesburg, 2024) Ngbede, Daniel; Kagura, Juliana; Mall, Sumaya
Background: Onchocerciasis is a neglected tropical disease and the second most common infectious cause of blindness worldwide, after trachoma. The vector which carries this parasite is a blackfly from the simulium genus, the parasite is transmitted to humans through the bite of an infected black fly during a blood meal. Alternative control strategies such as local vector control have been employed to complement the mass administration of ivermectin. There remains no synthesis of studies that have examined the use of vector control for onchocerciasis in the Sub- Saharan African (SSA) region. Objective: To examine the factors associated with vector control in the fight against onchocerciasis in Sub-Saharan Africa as through synthesis of the literature. Methods: A systematic search was conducted of the Cochrane Library, PubMed, Web of Science, and Scopus databases to identify relevant studies. Studies had to be published in peer-reviewed journals between January 2000 and March 2023. Data were extracted from the studies. Two independent reviewers conducted quality assessments using the Joanna Briggs Institute (JBI) critical appraisal checklist. Results: Our search identified 343 studies of which 19 were included in this review. Several factors were found to influence blackfly vector control programs. Programmatic factors include intervention duration and effectiveness, implementation challenges, resource availability, and larvicide application practices. Vector-related factors include blackfly susceptibility to larvicides, species variation, and genetic mechanisms of resistance. Environmental factors such as rainfall patterns, river size, and the presence of dams affect blackfly breeding sites. Human-related factors encompassed community knowledge and engagement, commitment to sustainability, and human activities that impacted breeding habitats. Overall, the quality of the included studies was found to be high as per the quality appraisal tool. Conclusion: This systematic review emphasizes the importance of considering multiple factors in the design and implementation of effective blackfly vector control programs for onchocerciasis in sub-Saharan Africa. Programmatic challenges, vector biology, environmental factors, and human factors should be considered. Policymakers and public health practitioners should optimize interventions based on these findings
Factors that promote and impede treatment adherence of out-patient mental health care users at a psychiatric hospital in Johannesburg
(University of the Witwatersrand, Johannesburg, 2024) Rowse, Savannah; Hlungwani, Tinstwalo Mercy
Background: Neuropsychiatric disorders are ranked third in the overall burden of disease in South Africa and are chronic disorders. Adherence (and nonadherence) to treatment for severe mental illness is a multifaceted phenomenon that influences and is influenced by multiple factors in one’s environment and context. However, due to the magnitude of this burden of disease and policy agendas promoting deinstitutionalization through community- based care, higher levels of services in South Africa are grappling with the revolving door phenomenon. Aim: To explore factors that promote and impede treatment adherence from the perspectives of mental health care users (MHCUs) in an outpatient department (OPD) Tara Hospital, Johannesburg in 2022/2023. Setting: Tara Hospital is a public specialized psychiatric hospital situated in Hurlingham, Johannesburg and is classified as tertiary and quaternary hospital due to the level of specialised services provided. MHCUs are referred from other tertiary hospitals in the Johannesburg metropolitan district or referred from the private sector for specialized services. Methods: An explorative, descriptive, and contextual qualitative research study was conducted over the 2022/2023 period at Tara Hospital’s OPD. Purposive convenience sampling was used to recruit 18 participants aged 18-65 and diagnosed with severe mental illness. In-depth interviews (IDIs) using a semi structured interview guide were conducted, transcribed, and then analysed using MAXQDA software. Results: A thematic analysis was used to highlight the five dominant themes and their sub themes that emerged from the research. The five dominant themes included: experience of mental illness and adherence, experience of Tara OPD, promoters of adherence, barriers to adherence and stigma. MHCU demonstrate rich insight into their experience of their mental illness, diagnosis, medication, and relapse. Tara OPD is protective factor and positive influence on adherence for its service users. MHCU’s engage dynamically with their adherence and use an array of practical strategies that support their adherence as well as emphasizing the positive influence of social and institutional support. The barriers to adherence included substance use, stigma, poor social support, poor routines, and coping strategies. This stresses the dynamic interplay and role of each level of the socio-ecological model. Conclusion: Adherence to treatment for severe mental illness does not occur in a vacuum of a MHCU simply taking their medication, but there are multiple factors and influences that are important to consider
Implementation of universal health coverage in South Africa: formative effects, perceived quality of healthcare and modelling of health service utilisation indicators in a national health insurance pilot district
(2024) Mukudu, Hillary
Background- According to the World Health Organisation, member countries should attain universal health coverage by 2030. To achieve this goal, South Africa introduced the National Health Insurance programme in 2012. Since then, the first phase of the pilot programme has been implemented in Tshwane and ten other country districts. Historically, no other health system reform in South Africa has generated more interest than the National Health Insurance. This 15-year preliminary plan and pilot received optimism and criticism depending on several factors. The pilot programme focusing on primary health care was implemented along with several other interventions. The components of the intervention included setting up: ward-based primary healthcare outreach teams, integrated school health programmes, district clinical specialist teams, centralised chronic medicine dispensing and distribution programmes, health patient registration systems, stock visibility systems, and contracting of private non-specialised (general) medical practitioners to provide services in public primary health care facilities. These interventions were envisaged to improve healthcare quality at the primary healthcare level and offset the burden of non-emergency (secondary) care at the hospital outpatient level. However, studies have yet to be done to determine population-level formative effects on primary and non-emergency secondary healthcare indicators, their relationships, and interdependencies. These data are needed to forecast and develop measures to meet the possible increase in health service utilisation. In addition, this information is essential to guide the possible scale-up of South Africa's National Health Insurance mechanism. Such guidance may be in setting benchmarks to monitor policy implementation, determine facility staffing, the package of health services, training needs, budget for medicines and consumables, and other resource allocation. Aim- Therefore, this study first aimed to determine the formative effects of implementing the Medical Practitioners' contracting of the National Health Insurance pilot program on primary healthcare utilisation indicators measured at both primary and non-emergency secondary levels of care. A comparison was made between Tshwane national health insurance pilot district and Ekurhuleni district, which is not a pilot district. Furthermore, the study aimed to determine the relationships between healthcare utilisation indicators and their interdependencies and then provide a forecast for 2025. Methods- This quasi-experimental and ecological study used selected primary health care and outpatient department indicators in the District Health Information System monthly reports between January 2010 and December 2019 for the Tshwane district and Ekurhuleni district. Thus, to determine the formative effects on primary healthcare utilisation indicators, the selected period was from June 2010 to May 2014. A total of 48-time periods (months), with 24 before (June 2010 to May 2012) and 24 after (June 2012 to May 2014) implementation of Medical Practitioners contracting of the National Health Insurance pilot programme. Similarly, June 2012 to May 2014 was the selected period to determine the effects on the perceived quality of care. A total of 24 months, with 12 before (June 2012 to May 2013) and 12 after (June 2013 to May 2014) implementation of the Medical Practitioners' contracting of the National Health Insurance pilot programme. To determine the relationship and interdependence between Primary Health Care and Outpatient Department indicators and forecasts for 2025, 113 time periods (quarters) were selected. There were 28 quarters before and 84 quarters after implementing the National Health Insurance pilot programme. Similar methodological approaches were used to determine the effects of Medical Practitioners contracting in the National Health Insurance pilot programme on Primary Healthcare utilisation indicators and perceived healthcare quality. All study data types used in the thesis were continuous; thus, they were initially evaluated descriptively using means (standard deviations) and medians (interquartile ranges). The range was evaluated using minimum and maximum values. An Independent t-test assuming unequal variances was used to compare the means of Outpatient Department indicators in determining the effect of Medical Practitioners contracting in the National Health Insurance pilot programme on the perceived quality of healthcare. Single- and multiple-group (controlled) interrupted time series analysis was used to determine the effect of the National Health Insurance pilot project implementation on the utilisation of selected primary and non-emergency outpatient department indicators and perceived healthcare quality. A different methodological approach was used to determine the interdependencies and relationships between selected primary healthcare and non-emergency outpatient department indicators and their forecasts for 2025. Initially, data were evaluated descriptively using means (standard deviations) and medians (interquartile ranges) and the range was evaluated using minimum and maximum values. Prior to the development of the vector error correction model, several steps were taken. Firstly, a natural log transformation of all time series data was done to enhance additivity, linearity, and validity. Additionally, the level of lags at which variables were interconnected or endogenously obtained was determined due to the sensitivity of causality. Furthermore, the stationarity of time series data was determined using both graphical means and the Augmented Dick Fuller test to confirm the stability of each time series. Finally, cointegration was determined using the Johansen cointegration test to check for the correlation between two or more nonstationary series. After developing the Vector Error Correction Model, the Granger causality test was done to determine whether one series is helpful for forecasting another. Then the Vector Error Correction Model relationships between variables of selected primary healthcare and non-emergency outpatient department indicators were used to forecast the utilisation of both levels of services by 2025. Results- The findings showed changes in primary healthcare indicators measured at primary and nonemergency secondary levels before and after contracting private medical practitioners of the National Health Insurance pilot programme. The study also confirmed the influence of selected primary health care and outpatient department headcounts on each other by finding four cointegration relationships between the variables. There were differences between single-group and controlled interrupted time series analysis findings for Tshwane district and Ekurhuleni district considered independently and collectively on the utilisation of primary health care services. Thus, the positive impact observed in primary healthcare utilisation post-June 2012 is not attributable to the implementation of the Medical Practitioners' contracting of the National Health Insurance pilot programme. Conversely, there were similarities between single-group and controlled interrupted time series analysis findings for Tshwane district and Ekurhuleni district considered independently and collectively on the perceived quality of primary healthcare. In the interpretation of this finding, the similarities indicated that implementing the Medical Practitioners' contracting of the National Health Insurance pilot programme positively influenced the perception of a better quality of primary healthcare in the Tshwane district. Regarding primary healthcare indicators, there were differences between single-group and controlled interrupted time series analysis. Single-group interrupted time series analysis showed a 65% and 32% increase in the number of adults remaining on anti-retroviral therapy in Tshwane and Ekurhuleni districts, respectively (relative risk [RR]: 1.65; 95% confidence interval [CI]: 1.64–1.66; p < 0.0001 and RR: 1.32; 95% CI: 1.32–1.33; p < 0.0001, respectively). However, controlled interrupted time series analysis did not reveal any differences in any of the post-intervention parameters. Furthermore, single-group interrupted time series analysis showed a 2% and 6% increase in the number of clients seen by a professional nurse in the Tshwane and Ekurhuleni districts, respectively (RR: 1.02; 95% CI: 1.01–1.02; p < 0.0001 and RR: 1.06; 95% CI: 1.05–1.07; p < 0.0001, respectively). However, controlled interrupted time series analysis did not show any differences in any of the postintervention parameters. In addition, single-group interrupted time series analysis revealed that there was a 2% decrease and 1% increase in the primary healthcare headcounts for clients aged ≥5 years in Tshwane and Ekurhuleni district (RR: 0.98; 95% CI: 0.97–0.98; p < 0.0001 and RR: 1.01; 95% CI: 1.01–1.02; p < 0.0001, respectively). Similarly, there was a 2% decrease and a 5% increase in the total primary healthcare headcounts in the Tshwane district and Ekurhuleni districts, respectively (RR: 0.98; 95% CI: 0.97–0.98; p < 0.001 and RR: 1.05; 95% CI: 1.04–1.06, p < 0.0001, respectively). However, controlled interrupted time-series analysis revealed no difference in all parameters before and after intervention in terms of total primary healthcare headcounts and primary healthcare headcounts for clients aged ≥5 years. Regarding secondary non-emergency outpatient department headcounts, single-group and controlled interrupted time series analyses revealed similar findings. Despite these similarities, single-group interrupted time series analysis showed a disparate increase in the outpatient department not referred headcounts, which were lower in the Tshwane district (3 387 [95%CI 901, 5 873] [p = 0.010]) than in Ekurhuleni district (5 399 [95% CI: 1 889, 8 909] [p = 0.004]). Conversely, while there was no change in outpatient department referred headcounts in the Tshwane district, there was an increase in headcounts in the Ekurhuleni district (21 010 [95% CI: 5 407, 36 611] [p = 0.011]). Regarding the outpatient department not referred rate, there was a decrease in the Tshwane district (-1.7 [95% CI: -2.1 to -1.2] [p < 0.0001]), but not in the Ekurhuleni district. Controlled interrupted time series analysis showed differences in headcounts for outpatient department follow-up (24 382 [95% CI: 14 643, 34 121] [p < 0.0001]), the outpatient department not referred (529 [95% CI: 29, 1 029 [p = 0.038]), and outpatient department not referred rate (-1.8 [95% CI: -2.2 to -1.1] [p < 0.0001]) between Tshwane the reference district and Ekurhuleni district. Four common long-run trends were found in the relationships and dependencies between primary healthcare indicators measured at the primary healthcare level and the non-emergency secondary level of care needed to forecast future utilisation. First, a 10% increase in outpatient departments not referred headcounts resulted in a 42% (95% CI: 28-56, p < 0.0001) increase in new primary healthcare diabetes mellitus clients, 231% (95% CI: 156-307, p < 0.0001) increase in primary healthcare clients seen by a public medical practitioner, 37% (95% CI: 28-46, p < 0.0001) increase in primary healthcare clients on ART, and 615% (95% CI: 486- 742, p < 0.0001) increase in primary healthcare clients seen by a professional nurse. Second, a 10% increase in outpatient department referrals resulted in an 8% (95% CI: 3-12, p < 0.0001) increase in new primary healthcare diabetes mellitus clients, a 73% (95% CI: 51-95, p < 0.0001) increase in primary healthcare headcounts for clients seen by a medical professional, a 25% (95% CI: 23-28, p < 0.0001) increase in primary healthcare headcounts for clients on ART, and a 44% (95% CI: 4-71, p = 0.026) increase in primary healthcare headcounts for clients seen by a professional nurse. Third, a 10% increase in outpatient department follow-up headcounts resulted in a 12% (95% CI: 8-16, p < 0.0001) increase in primary healthcare headcounts for new diabetes mellitus, 67% (95% CI: 45-89, p < 0.0001) increase in primary healthcare headcounts for clients seen by public medical practitioners, 22% (95% CI: 19-24, p < 0.0001) increase in primary healthcare headcounts for clients on ART, and 155% (95% CI: 118-192, p < 0.0001) increase in primary healthcare headcounts for clients seen by a professional nurse. Fourth, a 10% increase in headcounts for total primary healthcare clients resulted in a 0.4% (95% CI: 0.1-0.8, p < 0.0001) decrease in primary healthcare headcounts for new diabetes clients. Based on these relationships and dependencies, the outpatient department follow-up headcounts would increase from 337 945 in the fourth quarter of 2019 to 534 412 (95% CI: 327 682–741 142) in the fourth quarter of 2025, while the total primary healthcare headcounts would only marginally decrease from 1 345 360 in the fourth quarter of 2019 to 1 166 619 (95% CI: 633 650–1 699 588) in the fourth quarter of 2025. Conclusion -The study findings suggested that improvements in primary health care indicators in National Health Insurance pilot districts could not be attributed to the implementation of contracting private medical practitioners but were likely a result of other co-interventions and transitions in the district. However, it might have resulted in an improved perception of quality of care at primary health care facilities, evidenced by a reduction in the self-referral rate for nonemergency hospital outpatient departments. The study also confirmed the influence of selected primary healthcare and non-emergency outpatient department headcounts on each other by finding four common long-run trends of relationships. Based on these relationships and trends, outpatient department follow-up headcounts are forecasted to increase by two-thirds. Conversely, the total headcount for primary healthcare clients seen by a professional nurse will marginally decrease. Recommendations- Based on the study findings, the bidirectional referral between primary and non-emergency secondary levels of care in the Tshwane district should be strengthened to offset the burden of care at outpatient departments of district hospitals. Thus, the district health information system should include a down-referral indicator to monitor this activity. With the implementation of National Health Insurance, there is a need to improve the perception of quality of care at the primary healthcare level through appropriate training, recruitment, and placement of medical practitioners. Similarly, professional nurses, the core providers of primary healthcare services, should be supported and capacitated in line with the epidemiological transition.
Initial loss to follow up among tuberculosis patients: the role of Ward-Based Outreach Teams and short message service (SMS) technology
(2024) Mwansa-Kambafwile, Judith Reegan Mulubwa
Introduction: In South Africa, tuberculosis (TB) is still a serious public health problem with rates of initial loss to follow up (initial LTFU) varying between 14.9% and 22.5%. Poor clinician-patient communication resulting in lack of clarity on next steps, patients not prioritizing their healthcare and patients not knowing that their results are ready at the clinic are some reasons for initial LTFU. This PhD aimed to assess the effectiveness of Ward-based Outreach Teams (WBOTs) or Short Message Service (SMS) technology in reducing TB initial LTFU in Johannesburg, South Africa between 2018 and 2020. Methods: A mixed methods approach comprising two phases (formative and intervention) was employed. In the formative phase, secondary data were analyzed for frequency distributions to determine the rates of initial LTFU in the study area. In addition, in-depth interviews with WBOT Managers and with TB Program Managers were conducted to determine their perceived reasons for TB initial LTFU. In the intervention phase, two interventions (WBOTs/SMS technology) were tested using a 3 arm randomized controlled trial (RCT) comparing each of the interventions to standard of care (SOC). The WBOTs delivered paper slip reminders while SMS intervention entailed sending reminder SMS messages to patients as soon as TB results were available. Chi square statistics, Poisson regression and Kaplan-Meier estimates were used to analyze the data. The RCT was followed by in-depth interviews with WBOT members and with some of the trial participants who had tested TB positive and had received reminder messages. To identify themes in the qualitative studies, both inductive and deductive coding were used in the hybrid analytic approach. Results: From the formative phase, the TB initial LTFU among the 271 patients was found to be 22.5% and the overall time to treatment initiation was 9 days. Interviews with managers revealed that relocation and “shopping around” were the main patient related factors found as the reasons for initial LTFU. Health system related factors for initial LTFU were communication and staff rotations. In terms of TB related work, WBOTs screened household members for TB and referred them for TB testing. The services of the WBOT/TB programs which were found to be integrated were: referral of symptomatic patients for TB testing and adherence monitoring in patients already on TB treatment. There was minimal involvement of the WBOTs in the treatment initiation of patients diagnosed with TB. Findings from the trial were that 11% (314/2850) of the participants tested positive for TB. The 314 TB patients were assigned to one of the 3 arms (SOC=104, WBOTs=105, and SMS=105). Overall, 255 patients (81.2%) were initiated treatment across all study arms. More patients in the SMS arm were initiated TB treatment than in the SOC arm (92/105; 88% and 81/104; 78% respectively; P=0.062). Patients in the SMS arm also had a shorter time to treatment initiation than those in the SOC arm (4 days versus 8 days; P 8 days; P<0.001). A comparison of the WBOTs arm and the SOC arm showed similar proportions initiated on treatment (45/62; 73% and 44/61; 72% respectively) as well as similar times to treatment initiation. Findings from the post-trial interviews showed that delivery of the reminder paper slips by the WBOTs during the trial was something new, but possible to incorporate into their daily schedule. The patient interviews revealed that various emotions (happiness, fear, worry etc.) were experienced upon receipt of the reminder messages. Participants also reported that receiving the reminder message did influence their decision to go back to collect the results. Conclusion: Reminder messages to patients are beneficial in TB treatment initiation. National TB programs can use SMS messaging because it is an affordable and feasible method. Although implementation of the WBOTs intervention was suboptimal, findings show that with proper integration of TB and WBOT programs, WBOTs have the potential to contribute to improved treatment initiation.

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