3. Electronic Theses and Dissertations (ETDs) - All submissions
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Item Factors affecting virological outcome of paediatric patients on abacavir/stavudine-based first-line regimen(2019) Msiza, Duduzile PreciousBackground Viral load (VL) testing is recommended as the preferred monitoring approach for assessing the effectiveness of antiretroviral therapy (ART). Considering the factors which may predispose patients to treatment failure and the high rate of virological failure among paediatric patients, we investigate which characteristics have an effect on virological outcomes of young children. Objective To identify factors associated with an increased probability of first-line ART regimen failure and to report the rate of virological suppression in children below three years old initiated on stavudine (d4T) - or abacavir (ABC)-based first-line regimens. Methods This was a retrospective cohort study conducting a secondary analysis of an existing human immunodeficiency virus (HIV) treatment database of paediatric patients at the Empilweni Clinic based at the Rahima Moosa Mother and Child Hospital (RMMCH) in Johannesburg, South Africa, complemented by retrospective file review. Results From a population of 3,728 children attending the Empilweni clinic between 2008 and 2012, 296 were eligible for the study. The pre-treatment characteristics were gender, age, weight and height for age z-score, viral load, and cluster of differentiation 4 (CD4) count percentage at pre-ART. There was an upward trend in the VL suppression rate for all the variables during the study, with an average of 24% after 6-12 months of ART and 37% at 24-36 months of ART. The majority of patients were started on more than five different drugs in the first year of ART (99%), with an average adherence rate of 94%. Only a small percentage had treatment interruptions. Data on tuberculosis (TB) was available for 68% of the patients, of which 40% received HIV-TB co-treatment, mostly (90%) in the first year of ART. A total of 60% of patients had been exposed to prevention of mother-to-child transmission (PMTCT) therapy. Patients on a d4T-based first-line regimen had superior VL suppression compared to those on an ABC-based first-line regimen (p<0.0001). None of the other variables had a significant association on the VL suppression rate. Conclusion The study found that there was a delay in the VL suppression rate, with most patients still not being suppressed at 36 months of ART (40%). In this study ART regimen was found to be the only factor associated with viral load suppression.Item Safety and efficacy of antiretroviral first-line regimens in adults(2019) Venter, Willem Daniel FrancoisAs life expectancy in HIV-positive patients on antiretroviral therapy (ART) normalises, finding safer and cheaper ART options for decades of therapy, while preserving potency, is a healthcare priority. We surveyed doctors who were experienced in HIV care, using an anonymous online questionnaire, regarding World Health Organisation (WHO) HIV treatment guidelines, posing hypothetical scenarios, advising public health policy, treating family members or treating themselves (Chapter 2). Doctors approved of the WHO guidelines for public policy regarding antiretroviral drug choices (84%), CD4 initiation thresholds (54%) and monitoring (with the exception of isoniazid tuberculosis prevention (39%)). Doctors demonstrated concerns regarding the mitochondrial toxicity of stavudine (d4T) (lactic acidosis (38%) and lipoatrophy (37%)), as well as tenofovir (TDF) nephrotoxicity (55%) and efavirenz central nervous system side-effects (29%). They were significantly more likely to treat themselves, regardless of CD4 count, than public sector patients (95% odds ratio 3.33–7.33; P < 0.001). We examined low-dose d4T (20mg twice daily) as a replacement for TDF in a large, non-inferiority, placebo-controlled, double-blind randomised study (Chapter 6). HIV-positive adults in South Africa, Uganda and India were randomised to either d4T or TDF (536 in each arm) with lamivudine and efavirenz for 96 weeks. Completion rates were 75.7% for d4T (n = 406) and 82.1% (n = 440) for TDF, with non-completion largely resulting from virological failure (6.2% d4T vs 5.4% for TDF; p = 0.60). For the primary endpoint (viral load <50 copies/mL), d4T was non-inferior to TDF (70.3%, 425/536 vs. 80.8% 433/536; difference = -1.49%, 95% CI = -6.3-+3.3; P < 0.01). Side-effects were higher with d4T, with 6.7% (n = 36) discontinuations as opposed to 1.1% for TDF (n = 6; P < 0.01). Lipoatrophy was more common with d4T (5.6%; 30) than TDF (0.2%, 1; P < 0.001). In summary, low-dose d4T showed non-inferior viral suppression but substantial toxicity. The South African site participants were mostly recruited from ‘real-world’ primary health clinics, enabling analysis of the profile of patients entering public health programmes. Overall 771 patients were screened, who were mainly female (57%), with a mean age of 33.9 years (SD = 7.7), an initiation CD4 count of just over 200 cells/μL (median 208 cells/μl, IQR = 118–299 cells/ul) and high viral loads (39% > 100 000 copies/mL) (Chapter 7). Hepatitis B was highly prevalent (8%), 2% of patients had a haemoglobin<8g/dL, and neutropaenia was unusual. Creatinine clearance was >50mL/min in 99% of patients (microalbuminuria in 5%), raising questions about the need for routine pre-ART renal screening. CD4 cell count measurement is useful for predicting antiretroviral toxicity, immune recovery, immune inflammatory syndrome, prophylaxis indications and inform differential diagnoses. Using the same cohort, we analysed CD4 cell count variability between the referral, screening and baseline study visits (Chapter 8). All three CD4 cell counts were available for 553/771 patients. We found significant CD4 count variability across thresholds (350, 200 and 100 cells/μL), with 8% of patients referred below 350 cells/μL having screening values above that value (similar for baseline). Overall, 12% were misclassified at this threshold based on a CD4 cell count of > 350cells/μL on either screening or baseline (n = 64). A total of 17% of patients who had CD4 cell counts below 200 cells/μL at the time of referral had higher CD4 cell concentrations upon screening, and 24% were misclassified on either screening or baseline (n = 63). A total of 12–15% of participants were referred to the study when they had CD4 cell counts of under 100 cells/μL, but were found to be above 100 cells/μL upon screening or baseline, with 21% misclassified as having under 100 CD4 cells/μL on either one of these tests (n = 19). Based on the results of the referral, 17% of patients should have been classified as eligible for opportunistic infection prophylaxis, but they ineligible for opportunistic infection prophylaxis with subsequent testing. Around one in eight patients would be misclassified as falling within the 100 cells/μL threshold, with implications for cryptococcal antigen testing. An important recommendation was to alert clinicians to a range of possible (‘plausible’) values, so that misclassification does not occur through the application of rigid reported values. In conclusion, doctors broadly agreed with WHO guidelines, although resistance to implementation of TB prophylaxis is of concern; low-dose d4T was efficacious regarding viral load suppression, but associated with unacceptable levels of mitochondrial toxicity; TDF was very safe in terms of renal function, but bone changes on DEXA were of concern; patients routinely entering care for ART had little in the way of background laboratory renal or haematological abnormalities, but high levels of hepatitis B; and CD4 counts should be interpreted carefully at critical thresholds that may trigger additional testing or initiation of opportunistic infection prophylaxis. Future research work focusing on addressing the toxicity of ART, while preserving virological efficacy, as well as rational evidence-based laboratory screening and interpretation at initiation of ART, is needed.Item Nurse initiated and managed anti-retroviral treatment: An ethical and legal analysis in South Africa.(2014-03-28) Ford, PelisaThis research investigated the ethical and legal issues that impact on the urgent implementation of Nurse Initiated and Managed Anti-Retroviral Treatment (NIMART) in South Africa, which is part of the task-shifting strategy recommended by the World Health Organization (WHO) to deal with the human resource shortage that has negatively impacted access to Anti-Retroviral Treatment (ART) in developing countries (WHO;2006). The objectives were to review and analyse the existing legal framework and provisions for NIMART in South Africa; and to identify ethical issues and implications of NIMART within the current legal framework. It analysed the legal issues that impact on the implementation of NIMART within the public health service in South Africa, as well as the ethical basis and implications of NIMART on the practice of nurses in the scale-up of Anti-Retroviral Treatment in Primary Health Care (PHC). A comparative analysis was done with case studies of task-shifting in other developing countries and evidence-based recommendations for an enabling and long-term sustainable ethico-legal approach to task-shifting were established. The research concluded that despite the existing legal framework for NIMART in South Africa being firmly founded in the Constitution and further enabled by health policy, challenges exist in implementation of certain critical aspects of the enabling legislation relating to nurse training and accreditation required for full authorization to practice NIMART and that these technical challenges if not attended to could threaten the long-term sustainability of NIMART.