Electronic Theses and Dissertations (Masters)

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The in vitro diffusion across exercised porcine skin of various formulations of compounds used topically in the treatment of skin afflictions
(University of the Witwatersrand, Johannesburg, 2023) Elonga, Jessica; Eyk, Van
Introduction and Aim: Skin afflictions have been treated with topically applied active compounds since the ancient Greek era. Topical compounds mostly avoid first-pass metabolism and move directly into the local region of the skin or mucous membranes to exert their therapeutic effects. In this study, the aim was to investigate the in vitro diffusion characteristics of active compounds commonly used in topical formulations, such as caffeine, theophylline, retinol, L-carnitine, and Co-enzyme Q10 across porcine skin, used as a model for human skin. These compounds were tested alone and in combination within different topical formulations (liquid, gel, and cream) to investigate skin permeation, skin accumulation and effect on skin integrity. Methods: Method development and validation were performed to detect and quantitate all compounds tested by using a RP C18 HPLC system. Mobile phases included the following: caffeine and theophylline (Methanol:water [40:60], 20oC), retinol (Methanol:water [95:5], 20oC), L-carnitine (Sodium Phosphate buffer (pH 3.0):Methanol [99:1], 40oC) and Co-enzyme Q10 (Methanol:2-propanol [40:60], 25oC). All analyses were performed at 1 ml/min and injection volume of 20 μl. In vitro diffusion studies were performed using a PermeGear 7-in- line flow-through system. Either caffeine (2.5%), theophylline (2%), retinol (0.3%), L-carnitine (2%) or Coenzyme Q10 (0.5%) in various formulations alone, and in combinations were loaded into the donor compartments and PBS (pH 7.4) was pumped through the acceptor chambers at 1.5 ml/h (32°C, over 4 hours and 24 hours). The fluid collected (every 30 min or 2 hours) was analysed by RP HPLC. Skin accumulation for each compound was performed after completion of each experiment and skin integrity was established by measuring tissue resistance. Results: HPLC methods were found to be sensitive and valid for linearity, precision, accuracy and robustness. Retention times were as follows: caffeine 2.57±0.02 min, theophylline 2.18±0.03 min, retinol 2.91±0.02 min, L-carnitine 3.0±0.009 min and Co-enzyme Q10 3.15 ±0.003 min. From the in vitro diffusion studies of active compounds alone, caffeine within all formulations had the highest diffusion rate compared to theophylline and L-carnitine (caffeine>theophylline>L-carnitine). Retinol and Co-enzyme Q10 did not diffuse across the skin within a 24-hour time-period. In combination with Co-enzyme Q10, the diffusion of caffeine increased from both gel and cream formulations (p<0.05), while retinol increased the diffusion of theophylline from a liquid formulation (p<0.05). Theophylline increased the diffusion of L-carnitine from both liquid and gel formulations (p<0.05). Liquid and gel formulations without compounds, decreased the skin’s integrity after 24 hours and 2 hours, respectively. After 24 hours, the skin’s integrity decreased after exposure to all compounds tested (liquid and gel formulations), while the cream formulation mostly kept the integrity of the skin intact. Caffeine accumulated much more in the skin (>13%) compared to all the other compounds (<2.5%) for all three different formulations tested (caffeine>>L- carnitine>theophylline>retinol>Co-enzyme Q10). Combination studies mostly caused a decrease in accumulation of all compounds within the skin, except the following: retinol increased theophylline accumulation from a gel formulation and vice versa, Co-enzyme Q10 increased caffeine accumulation from all formulations and L-carnitine’s accumulation mostly increased when combined with other compounds. Conclusion: Caffeine was found to diffuse across and accumulate within the skin to a higher extent as compared to all the other compounds due to its ideal physicochemical characteristics. Very lipophilic compounds like retinol and Co-enzyme Q10 only accumulated to some degree in the skin. The findings indicated that the preferable combinations to increase efficacy, would be Co-enzyme Q10 in combination with caffeine, especially from a cream formulation, retinol in combination with theophylline (gel) and any of the compounds combined with L-carnitine (gel and cream). Cognisance must however be taken about possible systemic side effects
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
Efficacy of noise control measures at high noise zones from a copper mine in Zambia
(University of the Witwatersrand, Johannesburg, 2024) Nchimunya, Bbautu; Hayumbu, Patrick; Masekameni, Masilu Daniel
Noise exposure is a global problem, it is estimated that about 30 million workers in the United States of America (USA) are exposed to high noise levels while across Europe, 28% of the workers are exposed to high noise levels. Hazardous noise exposure is associated with a wide range of health effects that include noise induced hearing loss (NIHL), stress, poor concentration, communication difficulties and fatigue due to lack of sleep. The mining industry worldwide is struggling with hearing loss due to noise overexposure and in a copper mining set-up, the concentrator section is assumed to be among high noise zones exposing workers to noise above the occupational exposure limit (OEL) of 85 dB(A). This study aimed at evaluating the efficacy of noise control measures at various sections at Konkola Copper Mine concentrator section in Zambia. This quantitative cross-sectional study was conducted at Konkola Copper Mines (KCM) Konkola Business Unit (KBU) in Chililabombwe District in the Copperbelt Province of Zambia. A walk through survey was conducted to collect information to describe the operations, identify noise sources, understand noise release mechanisms and describe noise control measures. Quality control was achieved by triplicate noise measurement per location using an instrument with a valid annual calibration certificate. Raw data was pre-processed by cleaning to make it ideal for use. An ethical waiver W-CBP-230428-01 was granted as this study did not involve animal or human subjects but only area noise samples using CR: 172B SLM. The study identified the noise sources, described noise release mechanisms, described the noise controls and assessed the efficacy of noise controls in four sections within the concentrator of a copper mine in Zambia. Seventeen noise generating equipment were identified with about 53% of the equipment operated at the crushing section, 18% operated at the Flotation and Filtration section respectively and 11% at Milling section. A substantial portion (65%) of the identified noise sources in the concentrator are not housed, and among these, 36% are mobile in nature. It was also found that none of the noise areas were demarcated There are three types of noise controls (enclosure, silencer & HPD) that are in use at the concentrator and they fall in two categories of the hierarchy of controls (engineering & PPE). Out of the nine noise sources at the Crushing section, 56% (5 of the 9) utilized enclosure as control, 33% (3 of the 9) had HPDs as control and 11% (1 of the 9) source was installed with a silencer as a control. Enclosure is utilized to control noise from the two sources found in the Milling section while HPDs and enclosure are the noise control measures in use at both Flotation and Filtration sections of the concentrator. Enclosure is the most available control in the concentrator at 53%, followed by HPDs at 41%, and the least available is silencer at 6 %. About 76.5% (13) of the noise controls at the concentrator had efficacy strong enough to reduce noise levels to below the OEL while 23.5% (4) of the controls had weak efficacy that failed to reduce noise levels to below the OEL. This has prompted the need to strengthen efficacy in areas where controls were found to be weak. There is need to sustain controls that were found to be strong to maintain their efficacy. About 75% (3 of the 4) of the controls with lower efficacy were from the Crushing section while 25% (1 of the 4) was from Filtration section
The relationship between traumatic events and quality of sleep in older adults in rural South Africa
(University of the Witwatersrand, Johannesburg, 2024) Dzimbanhete, Tsitsi Cherry; Mall, Sumaya; Redman, Kirsten N.
Introduction: A number of factors are associated with the quality of sleep, a broad measure that includes sleep duration and disturbance. There are many factors associated with quality of sleep including communicable and non-communicable diseases and life course traumatic events (TE). Older adults who have experienced life course TE and the onset of comorbidities may be at risk of fluctuations in their quality of sleep. However, there are limited data on the African continent examining these relationships. Therefore, this study aimed to bridge the aforementioned gap and 1. examine the prevalence of traumatic events (TE), 2. examined the prevalence of poor quality of sleep in adults in the Health and Aging in Africa: a longitudinal study (HAALSI) cohort 3. examine the relationship between the TEs and quality of sleep in the HAALSI cohort in the Mpumalanga Province of South Africa. Methods: A cross sectional analysis using data from the second of four waves of the HAALSI cohort was undertaken. The second wave which recruited 4176 participants was conducted between 2018 and 2019. Measures include the English Longitudinal Study of Aging life history data to estimate prevalence of TE, brief version of Pittsburgh Sleep Quality Index (B-PSQI) to estimate the prevalence of poor sleep quality and the relationship between TE and poor sleep quality. Descriptive analysis, bivariate and multivariate analysis of the data was conducted in Stata 17. Results: The mean age of the participants was 65 years (SD=13). The majority of the sample were of South African origin (70%). With regard to education status, less than half (43%) had not completed a formal education (i.e., primary school). Poor quality of sleep was reported by 27% of the participants. With regards to TEs 66% of the sample reported caregiving trauma, 58% accident and disaster TEs, 30% childhood trauma, 15% war related TEs and 22% community violence. The multivariate analysis suggested that participants with history of exposure to childhood TEs and war related TEs had higher risk of poor sleep quality (OR 1.5 (CI1.2-1.8)) and (OR 1.5(CI 1.2-2.0)) respectively. The other variables associated with higher risk of poor sleep quality were being married (OR=1.2 (CI 1.0-1.4)) history of smoking (OR=1.6 (CI 1.2-3.1)), mild to moderate (OR=1.7 (CI 1.3-2.1)) and major depression symptoms (OR=2.1 (CI 1.8- 2.7)), being obese (OR =1.3 (CI 1.0-1.6)) and being HIV negative (OR= 1.4 (1.0-1.6)). Conclusion: Exposure to war related and childhood TEs were found to be associated with poor sleep quality in the older adults in rural South Africa. While a cross-sectional analysis is valuable, an examination of the full cohort of the trauma at baseline and quality of sleep would inform trauma focused interventions that seek to improve quality of sleep in older adults
Predictors of frailty and multimorbidity in adults aged 40 to 65 years in a rural population cohort in Burkina Faso
(University of the Witwatersrand, Johannesburg, 2024) Georges, Some; Kandala, Ngianga-Bakwin
Background: Frailty and multimorbidity are vulnerable geriatric syndromes that pose a disability problem among the elderly in Sub-Saharan Africa (SSA). Assessment of factors associated with frailty and multimorbidity in middle-aged adults has remained limited despite the prevalence established in previous studies. We determined factors associated with frailty and multimorbidity among middle-aged adults in rural areas from 2015 to 2022 in Burkina Faso. Methods: This study utilized data from the Africa Wits-INDEPTH Partnership for Genomic Research (AWI-Gen) sub-study, a retrospective cohort study of 1500 participants aged 40-65 residing in Nanoro and Yako in Burkina Faso between 2015-2022. Each participant was asked to complete a standardized and structured questionnaire on socio-demographic, lifestyle, and clinical information. In addition, measures of Fried's phenotypic frailty components, and twelve chronic diseases were assessed for derivation into frailty and multimorbidity score variants respectively. To determine the risk factors associated with frailty and multimorbidity, we performed an ordinal and multinomial logistic regression analysis respectively with a significance level of 5%. Results: The prevalence of pre-frailty and frailty was 59.3% and 8.5% respectively while that of multimorbidity was 38.3%, where the multimorbidity prevalence rate stratified by existing chronic diseases was 13.0%. Half of the participants who had multimorbidity were frail (47.2%) while 10.4% of frail participants had multimorbidity. Weight loss (23.9%) and self-reported exhaustion (23.1%) were the most frequent phenotypic components. Dyslipidemia (63.9%), hypertension (26.4%) and rheumatic arthritis (15.0%) were the most frequent chronic diseases. On the one hand, age (≥50 years, aOR 1.4[1.0-1.9]), being widowed (aOR 1.5[1.1-2.1]), being unemployed (aOR 2.5[1.1-5.8]), smokeless tobacco use (aOR 2.5[1.1-5.7]), being underweight (aOR 26.2[17.1-40.2]) and multimorbidity (aOR 1.4[1.0-2.1]) were independently associated with increased odds of frailty. However, fruits (aOR 0.9[0.8-1.0]) and vegetables consumption (aOR 0.9[0.8-1.0]), and being highly active in weekly activities (aOR 0.1[0.0-0.2]) significantly reduced the odds of frailty. On the other hand, age (≥60 years, RRR 1.8[1.1-2.8]), being a woman (RRR 2.6[1.7-3.9]), being widowed (RRR 1.6[1.0-2.7]), being unemployed (RRR 4.5[1.1-18.0]), overweight (RRR 5.0[2.8- 9.1]), obesity (RRR 3.4[1.1-11.0]), pre-frailty (RRR 1.8[1.2-2.6]) and frailty (RRR 2.1[1.0-4.2]) were strongly associated with an increased risk of multimorbidity. Nevertheless, the consumption of alcohol (RRR 0.4[0.3-0.6]) and fruit (RRR 0.9[0.8-1.0]) significantly reduced the risk of multimorbidity. There was no significant association with determinants such as gender, level of education, smoking status. Conclusion: These findings provide additional evidence on the determinants of frailty and multimorbidity in Burkina Faso. Community awareness initiatives should be strengthened to influence lifestyle on tobacco consumption, alcoholism, physical activity, and vitamin supplementation associated with the consumption of fruits and vegetables
The relationship between mental distress and somatization in hospital based health care workers in Gauteng during covid-19 pandemic in 2020
(University of the Witwatersrand, Johannesburg, 2023) Ramuedi, Ntsako Khosa; Kerry Wilson, Nioh
Background Mental distress among Health Care Workers (HCWs) is an urgent health concern, and somatization is a known outcome of mental distress. The Covid-19 pandemic increased stress for HCWs globally due to working with Covid-19 patients and resource limitations. Although there was already a lot of mental distress in HCWs in prior years, the coronavirus pandemic made matters worse, with 45% of people reporting that the pandemic had a significant negative impact on their lives. Somatization can lead to increased use of health services, sick leave and poor health. Service delivery is also impacted negatively if the service providers are not well or are suffering from the mental distress and are also showing symptoms. Aim To identify if a relationship exists between mental distress and somatization symptoms in Gauteng hospital-based health care workers in 2020. Objectives. To describe the prevalence of mental distress and somatization among health care workers by socio demographic status. To identify the somatization symptoms associated with high GHQ-12 scores in health care workers during Covid-19. To describe the association between mental distress and somatization among health care workers during covid-19 adjusting for demographic variables. Methods Health care workers can be described as anyone working in the health sector or at a health facility. All staff in the three selected hospital facilities in Johannesburg, were given the opportunity participate in the study. The PHQ-15 and GHQ-12 tools were used to collect information on HCWs somatization and mental distress after the first wave of the Covid-19 pandemic in South Africa. The anonymous questionnaire consisted of the two tools and demographic questions was used. The responses to each question on the tools were summed in order to determine severity of mental distress and somatization in HCWs, a higher score indicating more stress and or more somatization. Logistic regression was used to determine the adjusted relationship between somatization and mental distress. Results The study had a sample size of 295. A large proportion of participants (52%) reported suffering somatic symptoms. Males mean somatization score was significantly lower than the females. The majority (62%) of HCWs were troubled indicating a high burden of mental distress in the health care sector. The most commonly reported symptoms were back pain, headaches and being tired or low energy, all three were significantly associated with mental distress among others. There was a positive moderate correlation between PHQ-15 and GHQ-12 scores (0.30592) (p < 0.0001). Logistic regression indicated somatization was significantly associated with mental distress with a significant OR 2.14 (p = 0.0029) adjusted for demographic factors in these workers. Conclusions There was a statistically significant positive relationship between somatization and poor mental health. Health care workers with mental distress may be at risk of somatization, particularly specific symptoms such as back pain, headache and having low energy. Females were more bothered by most of the somatoform symptoms as compared to their male counterparts. Support for health care worker’s mental health is required as well as increased awareness of somatization linked to mental distress. Policies and services need to be developed to protect and support HCWs mental health during times of stress in the sector
The relationship between the combined effects of life-course trauma and HIV on cognition in rural South African adults: A secondary data analysis
(University of the Witwatersrand, Johannesburg, 2024) Kupa, Nkgodi Obed; Matsena-zingoni, Zvifadzo; Mall, Sumaya
Background: Lifecourse traumatic events (TE) refers to both childhood and adult trauma. Childhood TE refers to a spectrum and domains of adverse experiences occurring before the age of 18. Global and South African-based research suggests that life-course TE are associated with both physical and mental disorders including HIV and poor cognition (also referred to as neurocognitive impairment (NCI)). While data suggests that life-course TE, HIV and NCI are highly prevalent in South Africa and risk of NCI has been researched, little is known of the combined effect of life-course TE and HIV on NCI in adulthood. To fill the gap in the literature, I analysed data from the Health and Aging in Africa: A Longitudinal Study of an INDEPTH Community in South Africa (HAALSI), from rural Bushbuckridge (Mpumalanga province). Study Aim To examine the combined (interaction) effect of TE and HIV infection on the cognition of older adults in South Africa. Methods: I analysed (secondary) data from the HAALSI study. The main exposures analysed were: life-course TE and HIV-positive status. A pre-analysis phase consisted of several exploratory steps to define the exposure and outcome: First TE data which had been measured by the English Longitudinal Study of Aging (ELSA) life history questionnaire were examined. The main exposure variable was coded 1 if one experiences a TE and 0 otherwise from seven potential TE. NCI, the main outcome variable was defined based on measuring cognitive domains: orientation and memory. A score≥1.5 standard deviations (SD) below the mean of the baseline cognitive function distribution on the cognitive assessment (managing to know the date, day, month and president) will mean no NCI while a score below the means some degree of NCI). The main outcome variable was cognition measured by the Oxford Cognitive Screener (OCS-plus). Based on the validation of Tablet-Based OCS-plus in HAALSI, OCS-Plus included nine brief tests measuring cognitive ability in nine different domains, including language, memory (intentional and incidental), and executive functioning (task switching-alternating jobs between tasks), attention (auditory), and praxis (doing things). A stand-alone application called OCS- Plus was developed using Matlab and Psychophysics Toolbox for Windows Surface Pro tablets. Further preparatory steps for the analysis included: the exposure variables (HIV status and composite trauma-defined as the presence of at least one trauma item-) were created as follows: 1. HIV status was categorized into HIV positive and negative and coded 1 and 0 respectively. 2. Composite trauma was coded 1 if ever experienced any of the seven trauma items and 0 if none were experienced. Four groups of participants were created by exposure status. These were: 1. HIV positive and also experienced TE. 2. HIV negative but experienced TE. 3. HIV positive but TE negative. 4. HIV negative and trauma negative. Descriptive statistics were calculated for both exposures and outcomes as well as relevant sociodemographic variables. Both unadjusted and adjusted logistic regression techniques were employed to examine the combined effect of life course TE and HIV on NCI in older adults. The adjusted logistic regression models were done: 1) handling HIV and composite trauma separately and 2) considering the interaction term of HIV and composite trauma. Variables such as education, employment status, age, nationality, gender, hypertension, stroke, HIV status, marital status and composite trauma were considered confounders and adjusted accordingly. Results: Of the 5,059 study participants recruited and residing in the Agincourt study area in Bushbuckridge, 65% of the study participants had experienced at least 1 TE, and the most common trauma experienced were “ever experiencing severe financial hardship which was experienced by 58.74% of the participants, 39.73% whom “ever experienced a natural disaster” and 23.30% “ever experienced a death of a relative or friend” and the prevalence of NCI was 7% ( n=352).. The median age of participants was 64 (IQR: 55-74) years; 53.07% of the study participants were females; 44.42% had no formal education, and 72.63% of the study participants were not working. In the multiple logistic regression model with the interaction term, the odds of having NCI decreased by 64% (AOR=0.36; 95%CI: 0.25-0.52) and 59% (AOR=0.41; 95%CI: 0.24-0.75) among those who had some primary school (1-7 years) and some secondary school (8+ years), respectively compared to those with no education. The odds of having NCI decreased by 98% (AOR=1.98; 95%CI: 1.05-3.72) among those who were not working compared to those employed. A one-year increase in age was associated with a 5% increase in the odds of having a cognitive impairment (OR=1.05; 95%CI: 1.04-1.07). Those who were married had 37% (OR=0.63, 95%CI: 0.47-0.84) reduced odds of having NCI compared to those who were married. Those without composite trauma had 90% (AOR=0.10; 95%CI: 0.07-0.15) reduced odds of having NCI compared to those who have composite trauma. Those who were HIV positive and had experienced composite trauma had an increased odds of 1.78 (95% CI: 1.04-3.04) of having NCI compared to those who are HIV negative and had not experienced composite trauma. In the interaction model, we found no association between HIV status, stroke, or hypertension and NCI. However, the results of the interactionmodel suggested a significant association between HIV and the composite trauma score on NCI. Conclusions: The results suggest that lifecourse TE and HIV infection influence NCI. The full HAALSI cohort could be employed to examine the effect of TE data collected at baseline and incident NCI at later waves
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
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
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.
Risk factors for recurrent tuberculosis among HIV patients who are on anti-retroviral treatment in rural northeast, South Africa
(University of the Witwatersrand, Johannesburg, 2024) Kanzoole, Kingsley; Ibisomi , Latifat; Kabudula, Chodziwadziwa
Background: Tuberculosis (TB) is a major public health concern, and according to the World Health Organization (WHO), is one of the top 10 causes of death worldwide. Recurrent TB is a significant contributor to the overall TB burden worldwide, particularly in areas where TB prevalence is high (4–6), and among HIV infected people. Aim: In this study, we investigated the risk-factors that are associated with the recurrence of TB among HIV infected people in rural northeast, South Africa. Methods: The study employed a retrospective cohort study design and used data from Agincourt health socio-demographic surveillance system spanning from 1st January 2014 to 31st December 2022. Data analysis was conducted using STATA 17 SE as the analytical tool. Cox regression was used to determine risk factors for recurrent TB among HIV patients on ART in rural northeast, South Africa. Results: The study included 4,803 participants with 1,326 (27.6%) males and 3,477 females (72.4%). The participants were predominantly of HIV WHO Stage 1 (84.7%), followed by Stage 2 (7.6%), then Stage 3 (7.0%) and Stage 4 (0.7). The age distribution had 24.8% aged 18-29, 34.5% aged 30-39, 23.1% aged 40-49, 11.0% aged 50-59 and 6.6% aged 60 and above. The study population had a CD4 count median of 229 cells/mm3 with an IQR of 112-390 cells/mm3 and a median duration of previous TB treatment of 31 weeks with an IQR of 16-49 weeks. Out of the 4,803 patients, 396 (8.2%) experienced recurrent TB. This translated to a recurrence rate of 3.0 per 100 person years. The median time to TB recurrence was 1.93 years, with approximately 50% experiencing the recurrence within this period. The significant risk factors associated with recurrent TB were being male (AHR=1.48, CI: 1.11 – 1.96), WHO HIV stage (AHR=2.53, CI: 1.81 – 3.54), baseline CD4 count (AHR=0.98, CI: 0.98 – 0.99), and duration of previous TB treatment (AHR=0.96, CI: 0.93 – 0.98). Conclusion: This study has identified significant risk factors for recurrent TB among HIV patients in rural northeast South Africa. Male patients have a higher risk, necessitating targeted interventions. Advanced HIV stages increase recurrence risk, emphasizing early diagnosis and management. Maintaining higher CD4 counts and continuous monitoring during and after TB treatment are vital to reducing recurrence. These findings inform strategies to improve health outcomes and control recurrent TB among HIV patients receiving ART in the region
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
The association between intermittent preventive treatment uptake and anaemia amongst pregnant women in Zambia in 2018: a spatial analysis
(University of the Witwatersrand, Johannesburg, 2024) Chisiba, Charlotte; Musenge, Eustasius; Mapuroma, Relebogile
Background: This study investigated the association between Intermittent Preventive Treatment with Sulphadoxine Pyrimethamine (IPTp-SP) uptake and anaemia among Zambian pregnant women aged 15-49 in 2018. Despite WHO's endorsement of IPTp-SP to combat malaria-related anaemia, its prevalence continued to rise, significantly impacting maternal health. Methodology: Using Zambia Demographic Health Survey 2018 data, 665 pregnant women receiving IPTp-SP were analysed for haemoglobin levels, determining anaemia through blood tests. Statistical methods included survey-adjusted proportions, means, bivariate analysis, multiple linear regression, and multi-level ordinal logistic models with spatial random effects. Spatial analyses used ArcMap for coverage analysis, ordinary least squares, and geographically weighted regression maps (GWR) techniques in R and Stata. Results: Optimal IPTp-SP doses resulted in 36.98% anaemia prevalence (124/369), and suboptimal doses led to 42.85% (112/296). Factors associated with anaemia included household size, rich wealth index, high parity, and employment during pregnancy. Associations between IPTp-SP uptake and anaemia were identified: household size (four to six: AOR= 0.53; 95% CI 0.34 to 0.80; seven or more: AOR=0.57; 95% CI 0.35 to 0.91), adequate antenatal visits (AOR=0.68; 95% CI 0.48 to 0.97), and rich wealth index (AOR= 0.68; 95% CI 0.34 to 0.98). Spatial analysis revealed anaemia hotspots in Southern, Luapula, and Eastern provinces, with iron supplements and household size identified as influential factors. Conclusion: Despite IPTp-SP use, overall anaemia prevalence was 40%, with the highest rates in Southern, Luapula, and Western provinces. Targeted strategies focusing on improving iron tablet access, antenatal care attendance, and utilising spatial maps are crucial for mitigating adverse anaemia outcomes in these region
Occupational characteristics and economic activities of health workers in the quarterly labour force survey: 2008-2017
(University of the Witwatersrand, Johannesburg, 2024) Dinga, Aphiwe; Blaauw, Duane
ackground There is global emphasis on the importance of research and analyses of health labour markets. The latter is defined as dynamic systems consisting of the demand and supply of health workers, influenced by a country’s regulations and institutions. However, there is limited national data to inform a health labour market analysis. Aim The aim of the study was to analyse the demographic, occupational characteristics and the economic activities of health workers who were surveyed in the Quarterly Labour Force Survey (QLFS) from 1 January 2008 to 31 December 2017. Methodology This study was a cross-sectional secondary data analysis of the health workers captured in the QLFS, a household survey that is conducted every three months by Statistics South Africa. The survey focuses on the labour market activities of individuals aged 15 to 64 years who live in South Africa. The sample analysed for this study was all health workers surveyed in the QLFS during the study period. Both the South African Standard Classification of Occupations (SASCO) and the Standard Industry Classification (SIC) codes were used to extract data on all health occupations to ensure that the entire health workforce in the QLFS was included in the current study. To identify predictors of employment a multiple logistic regression was carried out. STATA ® 15 was used for the statistical analysis. Results The study sample comprised a total of 5 502 health workers. Nurses constituted the highest proportion of health workers in the survey (60.1%) while medical doctors and dentists represented 10.0%. Nurses were older than the other categories of health workers with a mean age of 43.6 years (SD±10.3), compared to the mean age of 41.8 (SD±10.8) for doctors, 38.6 (SD±10.4) for mid-level health workers and 37.8 (±10.8) for allied health workers. The majority (59.0%) of health workers were employed in the public sector, and in urban areas (83.8%). Only 4.6% of doctors and 7.0% of allied health workers were employed in rural areas. Overall, the study found that fewer than 1% of health workers reported more than one job during the 10-year period. The results of the logistic regression showed that the odds of employment were approximately two times higher for health workers between the ages of 36-45 and 46-55 years old and 1.8 times higher for health workers between the ages of 26-35. There were 0.5 odds of employment for health workers aged 56-64 years compared to the reference age group of 18–25-year-olds. Females were less (0R=0.56) likely to be employed as compared to males. Compared to health workers in urban areas, those in rural areas were less (0.47) likely to be employed. Health workers were 0.53 times less likely to be employed outside the health industry as compared to being employed in the health industry. Conclusion Although the QLFS provides useful information on the health workforce in South Africa, the results highlight the need for investment in a robust human resources for health information system
Noise emissions and exposures among drill operators and assistants in an opencast mine in South Africa
(University of the Witwatersrand, Johannesburg, 2024) Zamisa, Thulile Senzekile; Nelson, G
Background: Noise is defined as ‘undesirable’ or unwanted sound and is one of the most common occupational hazards in the workplace. Millions of workers are exposed to workplace noise that is potentially damaging to hearing. Noise also creates psychological stress, interferes with communication, concentration and can reduce productivity. Objective: The objectives of this study were to compare noise exposures between drill operators and assistants, to compare the noise emitted by drilling machines with noise exposures, and to identify risk factors associated with noise exposure in these workers. Methods: A quantitative cross-sectional study was conducted at an opencast Platinum Group Metals (PGM) and chrome mine in South Africa. Personal noise measurements were recorded throughout the work shift, for 40 drill operators and 20 assistants, using a noise dosimeter. The noise emitted from 10 drilling machines was also measured, using a sound level meter. Information on age, years worked as a drilling operator/assistant, and specific drilling machines operated, was collected. Information about the drilling machines, such as the area where drilling was done, the type of drill and material being drilled, and machine hours was also collected. Noise exposures for drill assistants and drill operators were compared, using an independent two-sample Student t-test. The two-paired Student t-test was used to test for the differences between noise emissions and noise exposures for the drill operators and assistants. To identify risk factors associated with noise exposure, a multivariable linear regression model was used. The independent categorical variables were age, time in job, shift cycle, job title, machine hours, material drilled, machine type, and deployment area. The independent continuous variables were noise inside the machine cab, noise outside the machine cab window, and noise at 1 m from the drilling machine. The dependent variable wasnoise exposure for drill operators and assistants. Results: The majority (n=40, 67.7%) of the study participants were drill operators; there were 20 (33.3%) drill assistants. Most (n=14, 70.0%) of the drill assistants were 35 years or younger, while most of the drill operators (n=19, 47.5%) were 36 – 45 years of age. The drill assistants were exposed to significantly higher mean TWA noise levels than the drilling operators, viz. 92.0 and 81.7 dBA, respectively. All drill assistants (n = 20) and 32.5% (n = 13) of the drill operators were exposed to mean TWA noise levels ≥85 dBA. There were statistically significant differences between the drilling machine noise emissions (both inside and outside the drilling machine cab) and the noise levels to which both groups of workers were exposed. Noise exposure levels were significantly associated with job title, machine hours, noise emissions outside the cab window, and the deployment area. Conclusion: Drill assistants were exposed to higher noise levels than drilling operators. The integrity of the cab may reduce noise exposure for the drilling operators. The noise emissions measured outside the cab window of the drilling machine were higher than those inside the cab and 1 m from the drilling machine. This indicated the importance of ensuring that cabs are designed to ensure reduced noise exposure for the drill operators. Drill assistants need to understand that maintaining a distance away from the drilling machine is important to reduce noise exposure levels. Knowing what factors are associated with noise exposure allows the mine to implement control measures to reduce such exposures. Controlling noise at the source is important, and employing detection tools for noise, such as real time monitoring, is necessary to record accurate employee exposures to assess if controls are effective
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
The effects of COVID-19 on paediatric therapeutic services at Chris Hani Baragwanath Academic Hospital
(University of the Witwatersrand, Johannesburg, 2024) McGrath, Robyn Lesley; Slemming, Wiedaad
Background: The COVID-19 pandemic has affected child health services worldwide, including in South Africa, where prioritisation of paediatric therapeutic services was lacking despite their vital role in health promotion and disease management. Aim: This study aimed to assess the impact of the COVID-19 pandemic on paediatric therapeutic services at a tertiary level hospital in Johannesburg, South Africa, focusing on service outputs, challenges, and innovations during 2020 and 2021. Methods: This study used a concurrent triangulation mixed methods approach. Quantitative analysis of service output data was combined with qualitative analysis of healthcare worker interviews. Integration was facilitated through a convergent design joint display during interpretation. Results: In 2020, patient contact sessions significantly decreased, particularly during lockdown phases, leading to missed diagnoses and adverse patient outcomes. Ineffective hospital management contributed to a lack of communication and direction for managers and clinicians which was worsened by the absence of national guidelines. Persistent trends of low service utilisation during the pandemic drove healthcare worker innovation, forcing healthcare workers to adopt a systems approach to decision making. Innovations centred on inter-professional communication and coordination, service re-evaluation and restructuring, new service delivery models, technology use, patient education and prioritisation, and adapting the duration and frequency of care. Conclusion: Paediatric services healthcare workers responded innovatively to pandemic challenges, with some solutions improving long-term service delivery efficiency. Insights from this study can enhance health system preparedness and inform planning for paediatric therapeutic services in South Africa, especially in anticipation of future events and the National Health Insurance scheme
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
Prevalence of Group B Streptococcus colonization and serotype distribution among pregnant women in South Asian and African countries
(University of the Witwatersrand, Johannesburg, 2024) Kwatra, Gaurav; Madhi, Shabir A.
Background: Recto-vaginal Group B Streptococcus (GBS) colonization in pregnant women at the time of labour is the major risk-factor for developing invasive GBS disease within 7 days of age (early onset disease; EOD). We investigated prevalence of GBS recto-vaginal colonization at the time of labour among pregnant women and vertical transmission to their newborns across six African and two south-Asian countries. Methods: This multi-country prospective, observational cross-sectional study was undertaken in six African [(Ethiopia (Adama city), Kenya (Kilifi), Mozambique (Manhica), Nigeria (Gwagwalada), Mali (Bamako) and South Africa (Johannesburg) and two Southeast Asian countries (Bangladesh (Mirzapur) and India (Vellore)]. Inclusion criteria included pregnant women 18 to 45 years of age, delivery at ≥37 weeks gestation and documented to be HIV-uninfected prior to study-enrolment. Lower vaginal swabs, rectal swabs and urine were collected from the mothers and separate skin surface swabs of the umbilicus, outer ear and axillary fold; and rectal and throat swabs were obtained from the newborn for GBS culture. Standardized sampling and culture using direct plating and selective broth media for detection of GBS colonization in the mother-newborn dyads was undertaken across the sites. Serotyping of GBS isolates was done in South Africa. Results: Overall, 6,922 pregnant women were enrolled from January 10th , 2016 to December 11th , 2018. Of 6922 women who were enrolled, 6514 (94.1%; 759 to 892 per site) were included in the analysis. Overall, the prevalence of maternal GBS colonization was 24.1% (95%CI 23.1- 25.2; 1572/6514) being highest in Mali (41.1%, 95%CI: 37.7-44.6; 314/764) and lowest in Ethiopia (11.6%, 95%CI:9.5-14.1; 88/759). The overall rate of vertical transmission of GBS was 72.3% (95%CI 70.0-74.4; 1132/1566); being highest in Mozambique (79.2%, 95%CI 73.3-84.2); 168/212) and lowest in Bangladesh (55.8%, 95%CI 47.5-63.8; 77/138). The five most common GBS colonizing serotypes were Ia (37.3%; 586/1572), V (28.5%; 448/1572), III (25.1%; 394/1572), II (9.2%; 144/1572) and Ib (6.5%; 102/1572). There was geographic variability in serotype proportion distribution. Serotype VII was the third most common serotype in India (8.5%, n=15/176) and serotype VI was mainly identified in Bangladesh (5.8%) and India (5.7%). Conclusion: Our study reported high prevalence of GBS colonization in most settings, with some geographic variability even within African countries. Our findings suggests that there is likely to be a significant burden of EOD across the study sites. Post-licensure vaccine effectiveness studies should also focus on maternal GBS serotype distribution as non-vaccine serotype replacement could occur due to vaccine immune pressure

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