Electronic Theses and Dissertations (PhDs)
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Item Salient beliefs, preferences and intention to use HIV pre- exposure prophylaxis among pregnant and breastfeeding women in Zambia(University of the Witwatersrand, Johannesburg, 2024) Hamoonga, Twaambo EuphemiaPregnant and breastfeeding women living in sub-Saharan Africa are at substantial risk for HIV infection, and maternal seroconversion may affect the quality of life for the mother, and is a risk for vertical transmission of HIV. Despite the adoption of PrEP into national guidelines for HIV prevention, its uptake in antenatal and postnatal settings in Zambia remains low. We used an exploratory sequential mixed methods design to explore facilitators and barriers to uptake of PrEP among pregnant and breastfeeding women (18 years or older) not living with HIV in Zambia. We purposively recruited 24 women for the qualitative component and conveniently selected 389 women for the quantitative component of the study at Chipata Level 1 Hospital in Lusaka. For qualitative data, Nvivo was used for data management and data was analysed using thematic analysis. Quantitative data was analysed using chi-square test, pearson correlation coefficient (r) and logistic regression analysis using Stata v.16. Findings from our qualitative study showed that women had positive attitudes and favourable intentions to use PrEP. Most women felt that people who are important to them, especially their male partners, would not support PrEP use during pregnancy and breastfeeding. The anticipated disapproval from partners made women believe that PrEP use would not entirely be under their control, with some reporting that they would not use PrEP if their partners disapproved. Women also cited rude health care provider attitude as a potential barrier to uptake. Some women preferred receiving PrEP from a health facility for fear of stigma in the community while others preferred community-based delivery as an avenue for creating PrEP awareness. This paper was published in Frontiers in Reproductive Health In our second paper, we determined intention to use PrEP during pregnancy and breastfeeding and also identified salient beliefs associated with it. Participants had positive attitude and favourable intention to use PrEP during pregnancy and breastfeeding (mean = 6.65, SD = 0.71 and mean = 6.01, SD = 1.36), respectively. They felt that people who are important to them would approve of their use of PrEP (mean = 6.09, SD = 1.51) and also believed that they would be able to use PrEP if they desired (mean = 6.52, SD = 1.09). All salient beliefs positively and significantly predicted intention to use PrEP during pregnancy and breastfeeding: attitude (β = 0.24, p<0.01); subjective norms (β = 0.55, p<0.01); and perceived behavioural control (β = 0.22, p < 0.01). This paper was published in Global Public Health. The third paper discusses findings from a discrete choice experiment (DCE) on preferences for PrEP service delivery among pregnant and breastfeeding women. In this study, waiting time, travel time, health care provider attitude and amount of PrEP supply at each refill were important considerations likely to influence PrEP use during pregnancy and breastfeeding (all p<0.01). Women expressed strong preference for 3-month’s supply of PrEP compared to other attribute levels (β= 1.69, p<0.01). They were willing to wait for 5 hours at the facility, walk for more than an hour to a facility dispensing PrEP, encounter a health care provider with a negative attitude as long as they received PrEP enough for 3 months. This paper is under review in Frontiers in Reproductive Health. The overall contribution of this PhD research to the body of knowledge on HIV prevention strategies is the ability to identify beliefs about PrEP and how each salient belief influences intention to use PrEP during pregnancy and breastfeeding. It is also one of the first to estimate the benefit (value or satisfaction) that women derive from different attributes of PrEP service delivery for pregnant and breastfeeding populations interested in using PrEP. This information could provide guidance on specific beliefs and service delivery attributes of PrEP that women prefer the most and therefore need to be prioritized if PrEP uptake is to improve in antenatal and postnatal settingsItem Adolescent health in rural South Africa: building an evidence-base to inform a health promotion intervention supporting healthier lifestyles(University of the Witwatersrand, Johannesburg, 2024) Seabi, Tshegofatso Martha; Kahn, Kathleen; Wagner, Ryan GBackground Low- and middle-income countries (LMICs), including South Africa, face the persisting double burden of malnutrition, with undernutrition and overnutrition coexisting within the population. This issue is particularly pronounced among rural adolescents, who experience limited access to healthcare services, inadequate infrastructure, poverty, and a scarcity of nutritious foods. Addressing this double burden of malnutrition is essential for improving the health outcomes of rural adolescents and breaking the intergenerational cycle of malnutrition. Community health worker-led interventions have shown promise in promoting healthier lifestyles in this population, making it crucial to understand the feasibility and acceptability of such interventions. Aim This thesis aims to provide context-specific information on the changing distribution of Body Mass Index (BMI) and views on obesity among rural South African adolescents to inform the development of a targeted behaviour change intervention. Furthermore, it seeks to determine the feasibility, acceptability, and overall experience of implementing a complex intervention aimed at promoting healthier lifestyles in this population. Methods Using a mixed methods approach focusing on adolescents 12-20 years of age living in rural South Africa. This work is nested within the MRC/Wits rural public health and health transitions research unit (Agincourt) Health and Demographic Surveillance System, which is where the sample was drawn and provided explanatory variables such as SES. This work includes data from two studies with comparable measures, conducted in 2007 (n= 1309) and in 2018 (n=518), this study analysed comprehensive data on the prevalence and trends of BMI, including both undernutrition and overweight/obesity, among rural adolescents in 2007 and 2018. This was done through weight and height measures. Growth z-scores were used to determine stunting, underweight and overweight and overweight/obesity was generated using the 2007 WHO growth standards for adolescents aged up to 17 years and adult cut-offs of BMI of <=18.5 for underweight and =>30 kg/m2 for overweight and obese respectively for adolescents 18 to 20 years. Qualitative data was collected in the form of focus group discussions and in-depth interviews. Pre-intervention, three focus group discussions were held with male (n = 16) and female adolescents (n = 15) focusing on obesity to capture views, attitudes and perceptions surrounding obesity. Post-interventions, six focus group discussions were held with male and female adolescents. In-depth interviews were conducted with adolescents (n=20), parents (n=5) and CHWs (n=3), focusing on the feasibility and acceptability of the health promotion intervention. All qualitative data were analysed using inductive thematic analysis. Results This study found that there is a persistent double burden of malnutrition amongst rural adolescents. The pattern of underweight and overweight/obesity remains similar between 2007 and 2018, with an increase in overweight and obesity, and a decrease in underweight observed across different age and gender groups throughout this period. The prevalence of stunting and underweight, particularly in males in both 2007 and 2018 was substantial although lower in the later year. Adolescents expressed conflicting views of obesity, highlighting their knowledge of the cause and long-term consequences of obesity. In regard to the intervention, participants expressed support for the CHWs and the community-based intervention guided by them. The findings demonstrated the feasibility of providing the intervention to adolescents in a rural context, with modifications needed to ensure participant uptake, such as changes to the time and location. Responses from participants show how the intervention, which included dietary and quantity modifications, was acceptable to adolescents. The gathered information in this study serves as a foundation for developing a health promotion intervention tailored to the specific needs and circumstances of rural adolescents, considering both undernutrition and overweight and obesity. Conclusion This research provides valuable context-specific insights into the burden of malnutrition and perceptions of obesity among rural South African adolescents, considering the complexities of the double burden of malnutrition. The findings contribute to the development of tailored health promotion interventions that address both undernutrition and overweight/obesity in this population. Understanding the feasibility and acceptability of such interventions is vital for successful implementation and sustainability in rural communities.Item Attrition in the dental therapy profession: an exploration of the contributing factors(University of the Witwatersrand, Johannesburg, 2024) Sodo, Pumla Pamella; Jewett, SaraBackground: A new type of oral health profession called dental therapy was introduced to address the growing need for affordable and accessible oral healthcare services, especially among marginalised communities. Extensive global research has demonstrated that dental therapists provide cost-effective and high-quality services, effectively addressing the issue of limited access to basic oral health services. The introduction of dental therapy into the South African healthcare system took place in 1977, however, disparities in accessing basic oral healthcare persist, particularly among some population groups where the highest prevalence of oral diseases has been reported. Despite being established over four decades ago, the number of registered dental therapists remains low, and there have been reports of attrition within this professional group. This PhD aimed to explore the factors contributing to attrition in the dental therapy profession. The first objective was to determine South African dental therapists' attrition rate and demographic profile over 42 years (1977-2019). The second objective explored factors contributing to attrition, while the third objective explored the applicability of the Hertzberg Two-Factor Theory in the context of dental therapy attrition in South Africa. Methods: This was a concurrent mixed methods study, involving registered graduate dental therapists, former dental therapists, and key stakeholders. The conceptual framework that guided the study was derived from Hertzberg's Two-Factor Theory. Data sources included the HPCSA registry and primary data collected using a quantitative survey investigating job satisfaction and intention to leave among registered graduate dental therapists and qualitative in-depth interviews with former dental therapists and key stakeholders to gain insights into their perspectives on attrition in the dental therapy profession. The attrition rate was determined by using the formula (Attrition Rate = Number of dental therapists who left the profession divided by the total number of dental therapists registered during the period of interest, multiplied by 100). Quantitative data was analysed in STATA version 15 using descriptive and inferential statistics, and qualitative data was analysed using thematic analysis. Findings: A total of 1232 dental therapists were registered with HPCSA over 42 years, with only 714 registered in 2019, two-thirds of whom were Africans. The attrition rate over the 42 years was 40%, while it reduced to 9% during the 10 years from 2010 to 2019. Of the 200 registered dental therapists who took part in the survey, 74.5% being Africans, approximately 51.5% expressed their intention to leave the profession and a notable 69.5% reported job dissatisfaction. In logistic regression analysis, job satisfaction correlated positively with several factors, including qualification from UKZN (AOR= 2.28, CI: 1.06-4.91), post-graduation job availability (AOR=3.87, CI: 1.73-8.69), awareness of postgraduate opportunities (AOR=2.28, CI: 1.05-4.96), and feeling valued (AOR= 6.91, CI: 1.45-26.36). Conversely, job satisfaction was negatively associated with becoming aware of the scope of work only after enrolment (AOR= 0.31, CI: 0.21-0.81). Job satisfaction was inversely correlated with the intention to leave; satisfied individuals had significantly lower odds of intending to leave (AOR= 0.25, CI: 0.11-0.57). In-depth interviews with 14 former dental therapists identified diverse reasons for enrolling in dental therapy and a shared enthusiasm for the dental therapy profession. Most reasons they cited for attrition, such as inadequate remuneration, job scarcity, poor working conditions, lack of career advancement opportunities, and policy implementation gaps aligned with Herzberg's Two-Factor Theory. One novel factor contributing to attrition not covered by the theory was a lack of professional identity. The 12 key stakeholders who were interviewed echoed similar factors contributing to the attrition of dental therapists. To address limitations in moving from a description of factors to recommendations on how to address system-level challenges, I adapted a framework that is a combination of Herzberg's Two-Factor Theory and the Human Resources for Health System Development framework. This new framework addresses multifaceted issues affecting dental therapists, covering production, deployment, and retention. Conclusion: This study sheds light on challenges within South Africa's dental therapy profession, highlighting their profound implications for both the profession and the broader healthcare system. Despite comparable attrition rates to other mid-level health professionals, there were alarmingly high job dissatisfaction levels and intentions to leave the profession, demanding immediate attention and intervention. Identifying key factors contributing to attrition and the novel insight into the lack of professional identity collectively highlight the multifaceted nature of the issue. To address these challenges, embracing a comprehensive human resource retention framework is imperative. This study emphasizes the urgent need for proactive measures to ensure the sustainability and contentment of dental therapists, ultimately benefiting the healthcare system and the communities it serves. Addressing these factors will lead to increased retention rates and improved access to basic oral health services nationwideItem Exploring the relationship between orphanhood status, living arrangements and sexual and reproductive health outcomes among female adolescents in Southern Africa(University of the Witwatersrand, Johannesburg, 2024) Shoko, Mercy; Kahn, Kathleen; Ginsburg, CarrenAdolescent Sexual and Reproductive Health (ASRH) is high on the global development agenda. Among the respective research conducted is the various social contexts that may contribute to adverse SRH outcomes, including the overlapping issues of orphanhood and living arrangements. These are crucial given that the presence or absence of parents emerges as critical for the sexual and reproductive well-being of adolescents. While orphanhood, particularly in the context of the HIV epidemic in Southern Africa, receives considerable attention, this study highlights a noteworthy gap in the literature – the limited focus on living arrangements and its influence on ASRH, often overshadowed by orphanhood. This research is important given the evidence suggesting that the African traditional kinship care systems offer support for orphans. However, recent research also highlights the crucial role of biological parents in providing effective care and support for adolescents. The study aims to contribute by exploring the relationship between orphanhood status, living arrangements, and ASRH in Southern Africa. Utilising cross-sectional Demographic and Health Survey (DHS) data, the analysis delves into key dimensions of SRH, including sexual debut, HIV knowledge, and adolescent fertility, which are all critical links to HIV risk. The findings underscore a significant association between non-coresidency with parents, whether due to orphanhood or separate living arrangements, and a heightened risk of adverse SRH outcomes. This suggests that interventions aimed at addressing adolescent SRH in Southern Africa should encompass a holistic understanding of parental presence or absence. The study emphasises the complex interplay between orphanhood, parental absence, and various individual, household, and geographic factors that collectively contribute to the vulnerability of female adolescents in the context of ASRH. Despite that the results suggest that the data on orphanhood and living arrangements may be of acceptable quality, the study recognises the potential for detailed insights through future research employing longitudinal data. Such an approach could offer a more nuanced and comprehensive understanding of ASRH over time, subsequently informing targeted policies and interventions in the unique socio-cultural context of Southern AfricaItem The development of a competency-based programme for management of disease outbreaks(University of the Witwatersrand, Johannesburg, 2024) Engelbrecht, LinettePurpose: The purpose of this study was to develop, a competency-based programme for the management of disease outbreaks. Method: The study utilized an exploratory sequential mixed method approach, using both qualitative and quantitative methods to develop a competency-based program. This study was conducted in South Africa, Gauteng, whilst the country was experiencing the third COVID-19 wave (May 2021 – October 2021), the fourth COVID-19 wave (December 2021– April 2022), and the fifth (May 2022 – July 2022), as well as the post-pandemic phase. The study was conducted in three phases namely: Phase One: Exploratory phase, Phase Two- Development of the programme Phase Three- Validation of the programme. In phase one, a scoping review on the existing literature was conducted using the Joanna Briggs Institute methodological approach. Following this were individual in-depth interviews with purposively sampled healthcare professionals as well as professional nurses. Through reflexive thematic analysis themes were identified for inclusion in the Delphi-survey in the next phase. For the second phase, a Delphi-survey was developed based on the data from phase one. The Delphi-survey consisted of two rounds whereby categories were identified to be included in the competency-based curriculum. A curriculum, consisting of ten modules was developed using the Backward design. In phase three the curriculum matrix was validated by experts. Results: A total of 62 publications were included in this study. Three categories and eight sub-categories were identified as needs of nurses during disease outbreaks. In-depth interviews with healthcare professionals resulted in the development of eight themes and 21 sub themes (challenges) of nurses. The in-depth interviews with nurses resulted in the development of 11 themes (challenges) of nurses. The results of the scoping review and in- depth interviews were used to develop a Delphi-survey. Experts in this two-round Delphi survey validated the domains and statements. The results of the Delphi-survey was used to develop a curriculum matrix consisting of ten modules, which was validated by three experts. Conclusion: A competency- based curriculum was developed based on the challenges nurses experienced working through the COVID-19 pandemic. This program could contribute to the development of disease outbreak competent nursesItem Trend of Pre-antiretroviral Therapy HIV-1 Drug Resistance in Kilombero and Ulanga Antiretroviral Cohort, South-Western Tanzania, for over 15 years (2005-2020)(University of the Witwatersrand, Johannesburg, 2024) Ntamatungiro, Alex; Kagura, JulianaIntroduction Pre-treatment HIV drug-resistance (PDR) may result in increased risk of virological failure and subsequently acquisition of new HIV drug resistant mutations. With recent increase in antiretroviral therapy (ART) coverage and periodic modifications of the guidelines for HIV treatment, monitoring changes in levels of PDR is critical, particularly in under-sampled areas, such as rural Tanzania. This PhD project aimed to determine the trend and patterns of PDR in the Kilombero and Ulanga antiretroviral cohort (KIULARCO), analyse the impact of recent HIV-1 infection, and dolutegravir rollout in rural Tanzania. Methods The study comprised a systematic review and meta-analysis of primary studies about prevalence of PDR among ART-naive people living with HIV (PLHIV) (³15 years old), published between 2017 and 2022. The data had to be in one or several of the countries of Eastern Africa, namely, Ethiopia, Kenya, Malawi, Rwanda, Mozambique, Tanzania, and Uganda. Thereafter, cross- sectional analyses of data on newly HIV-1-diagnosed ART-naïve adults (aged ≥ 15 years), enrolled in the on-going prospective clinic-based observational rural antiretroviral cohort- KIULARCO focusing on various aspects of PDR. Multivariate logistic regressions were used to determine the factors associated with recent HIV-1 infection, and viral suppression at 12-months in patients initiating dolutegravir-based ART in the KIULARCO. Results Overall, the pooled prevalence estimate of any PDR was 10.0% (95% CI: 7.9%–12.0%, I2 =88.9%) among 22 studies in the general adults’ population, which was higher than the previously reported prevalence of 8.7% using data available until 2016 in the Eastern Africa region. PDR was mainly driven by non-nucleoside reverse transcriptase inhibitors (NNRTI); whereas the pooled prevalence of PDR to nucleoside reverse transcriptase inhibitors (NRTI) was 2.6% (95% CI: 1.8%–3.4%, I2=69.2%). Remarkably, PDR to NRTIs in a sub-population of recently HIV-1 infected PLHIV in the KIULARCO was high at 12.5%. Also, there was a notable tendency to an increasing prevalence of PDR to NRTI, with the overall prevalence of 2.1% in the first five-year period (2005-2009) of the ART program in Tanzania, and 3.4 % in the most recent period (2019-2022). Moreover, there was no PDR to the dolutegravir co-administered NRTI in those with viremia ≥50 copies/mL, at one year, in patients initiating dolutegravir-based ART in the KIULARCO 2 years after dolutegravir roll. Notably, dolutegravir-based ART was associated with >2 times the odds of viral suppression compared to NNRTI-based ART with an adjusted odds ratio (aOR) of 2.10 (95% CI 1.12-3.94). Conclusions There is notable level of PDR to NRTI among general adults’ population in Eastern Africa region, that was high among recently HIV-1 infected PLHIV in a representative rural Sub-Saharan Africa setting. Hence, routine surveillance of pre-existing resistance to the DTG co-administered NRTI remains particularly important, in resource-limited settings, to prevent risk of failure of newer antiretroviral agents such as dolutegravir, which would be detrimental to Tanzania and other low- and middle-income countries for the aim to “end AIDS by 2030”. Our results underline the benefit of programmatic uptake of dolutegravir -based ART in low- and middle-income countries.Item 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 BirriBackground: 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.Item The relationship between violence across the life course, protective factors and mental disorders among adult women living in a slum setting in Ibadan, Nigeria(2024) Sekoni, Olutoyin OlubunmiResearch suggests that adult women in Nigeria have experienced traumatic events (TE) across their life course. Violence is a TE that can occur within intimate relationships as well as other spheres of life. TE and adverse life events can increase risk of a mental disorder such as: depression, anxiety and Post Traumatic Stress Disorder (PTSD). Despite experience of TE or adverse life events, some women do not experience the onset of a mental disorder which may be due to protective factors such as resilience and social support. The links between lifecourse TE and the development of common mental disorders have not been well researched on the African continent particularly in slum settings. This thesis aimed to investigate the relationships between adult women’s childhood trauma, experiences of Intimate Partner Violence (IPV) and adverse life events and common mental disorders among adult women living in a slum setting in Ibadan, Nigeria. The thesis also sought to examine the presence of protective factors in these relationships. Methods -A community-based cross-sectional household survey utilizing multistage sampling was carried out among 550 women. Childhood trauma was measured using the short form of the Childhood Trauma Questionnaire. IPV was measured using the WHO Multi-country Study on Women's Health and Domestic Violence Questionnaire. Common mental disorders were measured using the short version of the Depression, Anxiety and Stress Scale (DASS-21) while the Harvard Trauma Questionnaire was used to measure PTSD. Recent stressors were measured using the Life Events Questionnaire. The protective factors of resilience, social support, social connectedness and self- esteem were measured using the Wagnild and Young resilience scale, the Multidimensional Scale of Perceived Social Support, the Social Connectedness Scale (Revised) and the Rosenberg self-esteem scale respectively. Bivariate and multivariate analysis were conducted to identify any associations and net effect of the key independent variables on the primary outcomes of interest while controlling for socio demographic characteristics. Results The prevalence of lifetime and past year experience of IPV were 31.5% and 14.8% respectively. The prevalence of the TE during childhood ranged from 8.9% (sexual abuse), 50.4% physical abuse and 70.4% emotional abuse, while 30.8%, 41.6% and 5.8% had experienced one, two and three forms of childhood trauma respectively. Women who had experienced all three forms of childhood trauma had five times the odds of reporting a lifetime experience of IPV compared to those who had not had any experience of childhood trauma (OR= 5.21; CI= 2.30-11.76). Common mental disorders were reported by 14.0% of the respondents, with PTSD reported by 4.18%. Resilience and social support were found to be protective against reporting symptoms of common mental disorders. Women who reported higher levels of social support and resilience were less likely to report common mental disorders (OR:0.96, 95% CI 0.93, 0.98) and (OR:0.95, 95% CI 0.91, 0.99) respectively. Women who were 65 years and older were also less likely to report the occurrence of common mental disorders (OR:0.38, 95% CI 0.15, 0.98) compared to those aged 18–34 years. Conclusion- The findings from this study show that trauma over the life course is prevalent among the women in these slums as a result of childhood trauma, IPV and recent stressors. The findings also show that even though many of the women were exposed to trauma, most of them did not develop mental disorders. Resilience and social support appeared to play an important role in mitigating the effects of adversity among this population of women even in the light of their extant circumstances within the slum setting. Addressing the use of both child protection programs and IPV reduction as well as fostering resilience and social support among women would be of benefit in reducing the burden of common mental disorders.Item 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 AnnIncluded 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.Item Modelling space and time patterns of HIV interventions on HIV burden in a high priority district in South Africa(2024) Otwombe, Lucy ChimoyiBackground: Ekurhuleni Metropolitan Municipality (EMM) collects monthly data from primary healthcare facilities on the HIV programmes to inform its HIV response. To study patterns of HIV burden and uptake of HIV services at a population level, the application of small area analysis offered a powerful epidemiological approach while investigating on a geographical scale, the risk, and confounding factors of certain health outcomes. This PhD thesis was aimed at highlighting and understanding the heterogeneity of HIV prevalence and selected HIV outcomes at a ward-level between 2012 and 2016. Materials and Methods: Materials and Methods: A mixed-methods approach using the HIV result chain logical framework was applied to several sources of data. Firstly, data from a National HIV Survey, the South African National Census analysed using Bayesian techniques in WINBUGS to provide an epidemiological profile of the risk factors for HIV prevalence, sub-optimal condom use and non-ART use. Secondly, a model of time and space using R-INLA applied to routinely collected HIV program data (clinical and laboratory) assessed the predictors of viral load suppression (VLS) [<1000 copies/mL (WHO) and <400 copies/mL (SA)]. Forecasting of VLS (five years post-2016) was conducted using ARIMA models. Lastly, a thematic analysis using the social cognitive theory framework on in-depth interviews with patients and healthcare staff was conducted to understand factors influencing uptake of selected HIV services in different geographical settings Results and findings: There were several clusters of high HIV infection, sub-optimal condom, non-ART use and VLS in EMM driven by different risk factors discussed in this PhD thesis. The proportion of VLS increased from 2012-2015 and decreased in 2016, and heterogeneity was observed at ward-level. As the female population and ART initiation rates increased at ward-level, VLS increased. However, this observed relationship was strong in some areas and weak in others. Lastly negative sequalae including stigma from healthcare workers and communities prevented optimum uptake of HIV services, particularly in women. Social support, availability of services and differentiated care encourage utilisation of HIV services. Conclusions: Findings highlighted the heterogenous nature of health events in EMM and are likely to inform targeted interventions to improve HIV programmes at ward-level towards achieving the 95-95-95 targets.