Magister Public Health - MPH / The HIV prevalence rate in Zimbabwe has been estimated at 15% (15 years old and above), which is one of the highest in the world, and HIV/AIDS remains a significant public health problem. The focus of HIV prevention strategies has been on heterosexual transmission since this is the primary driver of the HIV epidemic in Zimbabwe. Heterosexual serodiscordant couples represent an important subpopulation for HIV prevention but are not well studied in Zimbabwe. In Harare almost all serodiscordant couples participating in the HPTN 052 study reported correct and consistent condom use. However, rates of STIs and pregnancies showed that couples in the study continued to have unprotected sex, in-spite of intensive couples’ counselling, quarterly follow up visits and provision of condoms. The aim of this qualitative study was to explore barriers to condom use by these serodiscordant couples in which one partner was on ART in Harare, Zimbabwe. It used a two stage qualitative approach with semi-structured interviews being the primary method of data collection. These interviews were conducted on a sample of five study staff, 15 serodiscordant couples and individuals enrolled in the HPTN 052 study in Harare, Zimbabwe after consent was obtained. Thematic analysis was used to analyse data collected.The study findings showed that partners were in a fairly large age range (30 to 50+ years) with males being slightly older than females. Seven males and five females were HIV positive. Couples had a wide variation in the length of their relationships, from one month to over 15 years as a couple. The study findings also showed that individuals in serodiscordant relationships understood serodiscordance. Problems unique to these couples were identified and broadly categorized as dealing with an HIV positive result, accepting serodiscordance, and difficulty of disclosing serodiscordance to family. Couples also showed understanding of the importance of condom use in a discordant relationship. The most common reason for using condoms was to prevent transmission of HIV to the uninfected partner. The main barriers to condom use were the strong desire to have children, male partner reluctance to use condoms and the influence of the negative partner in determining condom use. Based on these findings, a nuanced approach to prevention strategies, such as condom use and couples counselling and testing, is required. The aim should be to increase understanding of serodiscordance, risk and condom use at all sessions or contacts with couples.

Aim To determine the demographic and socio-economic characteristics of patients accessing antiretroviral treatment, in the public sector in Zambia. Methods A descriptive cross-sectional survey, using a pre-structured interview questionnaire, with patients on antiretroviral treatment. A total of 200 patients receiving antiretroviral treatment at the 2 national referral hospitals and seven provincial hospitals providing ART were included in the study Data was analyzed using STATA version 8. Analysis was by frequency tables and summary statistics. Results The majority of the patients on antiretroviral treatment were females at 61.5 percent. Most of the patients were in the age group 40 - 44 years old. Most of the patients were married followed by those who were widowed, who were predominantly female. The net monthly income was generally low for most patients and the forty thousand Kwacha monthly contributions for ARVs was high for most patients. Higher levels of education were associated with increased access to antiretroviral treatment. Conclusion and Recommendations There were more females than males accessing antiretroviral treatment in the public sector in Zambia. The majority of patients have a low income and the forty thousand Kwacha monthly contributions towards ARVs was high for most patients. It is recommended that antiretroviral treatment be provided for free or at a highly subsidized cost and also that the Ministry of Health increases the ART centers if the goal to put 100,000 on treatment by the end of 2005 is to be achieved. / Dissertation (MPH)--University of Pretoria, 2009. / School of Health Systems and Public Health (SHSPH) / Unrestricted

The research undertaken in these studies aimed to investigate the feasibility of developing and manufacturing innovative solid lipid carriers, such as solid lipid nanoparticles (SLN) and/or nanostructured lipid carriers (NLC) using a hot high pressure homogenization method, for didanosine(DDI). In addition, studies using in vitro differential protein adsorption were undertaken to establish whether the SLN and/or NLC have the potential to deliver DDI to the central nervous system (CNS). Prior to initiating pre-formulation, formulation development and optimization studies of DDI-Ioaded SLN and/or NLC, it was necessary to develop and validate an analytical method for the in vitro quantitation and analysis of DDI. An accurate, precise and sensitive RP-HPLC method with UV detection set at 248 nm was developed, optimized and validated for the quantitative in vitro analysis of DDI in formulations. Pre-formulation studies were designed to evaluate the thermal stability of DDI and to select and characterize lipid excipients that may be used for the manufacture of the nanocarriers. It was established that DDI is thermostable at temperatures not exceeding 163°C and therefore a hot high pressure homogenization technique could be used to manufacture DDI-loaded SLN and/or NLC. Lipid screening studies revealed that DDI is poorly soluble in both solid and liquid lipids. A combination of Precirol® ATO 5 and Transcutol® HP was found to have the best solubilizing-potential for DDI of all lipids investigated. The inclusion of Transcutol® HP into Precirol® ATO 5 changed the polymorphic form of the solid lipid from the stable 13-modification to a material that exhibited the co-existence between α- and β-polymorphic forms. The relatively high solubility of DDI in Transcutol® HP compared to Precirol® ATO 5 was an indication that a solid lipid matrix prepared from a binary mixture of Precirol® ATO 5 and Transcutol® HP was likely to have a higher loading capacity and encapsulation efficiency for DDI than a matrix consisting of Precirol® ATO 5 alone. Furthermore, the potential for the solid lipid matrix to exist in the α- and/or β-modifications when Transcutol® HP was added to Precirol® ATO 5 suggested that expulsion of DDI from a solid lipid matrix during prolonged storage periods was likely to be minimal. Therefore it was considered logical to investigate the feasibility of incorporating DDI into NLC and not in SLN. However, due to the limited solubility of DDI in lipids, formulation development of DDI-loaded NLC commenced using small quantities of DDI. Formulation development and optimization studies of DDI-loaded NLC were initially aimed at selecting a surfactant system that was capable of stabilizing NLC in an aqueous environment. Solutol® HS alone or a ternary mixture consisting of Solutol® HS, Tween® 80 and Lutrol® F68 was found to stabilize the nanoparticles in terms of particle size and the polydispersity index. The use of the ternary mixture as the surfactant system was preferred to using Solutol® HS alone as Lutrol® F68 and especially Tween® 80 have been successfully used to target the delivery of API to the brain. Aqueous DDI-free and DDI-Ioaded NLC containing increasing amounts of DDI were manufactured using hot high pressure homogenization at 800 bar for three cycles. The NLC formulations were characterized in terms of particle size, polydispersity index, zeta potential, and polymorphism, degree of crystallinity, encapsulation efficiency (EE), shape and surface morphology. The mean particle size for all formulations was below 250 nm with narrow polydispersity indices, indicating that narrow particle size distribution had been achieved. The d99% values for all formulations tested, were generated using laser diffractometry, and were below 400 nm, with span values ranging from 0.84 - 1.19 also suggesting that a narrow particle size distribution had been achieved. The zeta potential values measured in double distilled water with the conductivity adjusted to 50 μS/cm ranged from -18.4 to -11.4 mV. In addition, all the formulations showed a decrease in the degree of crystallinity as compared to the bulk lipid material and WAXS shows that the formulations existed in a single β-modification form. Furthermore DDI that had been incorporated into the NLC appeared to be molecularly dispersed in the lipid matrices. These parameters remained unaffected for most formulations following storage for two months at 25°C. In addition these formulations contained a mixture of spherical and non-spherical particles irrespective of the amount of DDI that was added during the manufacture of the formulations. These studies showed that it was feasible to develop and incorporate small amounts of DDI into NLC. However in order to use these delivery systems for oral administration of DDI to paediatric patients, strategies to improve the amount of DDI that could be loaded into the particles and to achieve high encapsulation efficiencies had to be developed. The limited solubility of DDI in lipid media was identified as a major factor that affected the loading capacity and encapsulation efficiency of DDI in the NLC. Therefore, a novel strategy aimed at increasing the saturation solubility of DDI in the lipid by attempting to increase the dissolution velocity of the drug in the lipid using a particle size reduction approach, was designed and investigated. DDI was dispersed in Transcutol® HP and the particle size of DDI in the liquid lipid medium was reduced gradually using hot high pressure homogenization and the product obtained from these studies was used to manufacture DDI-loaded NLC using a cold high pressure homogenization procedure. Although the encapsulation efficiency and drug loading following use of this approach was relatively high, the particles were large and showed a tendency to grow in size leading to the formation of microparticles after storage for two months at 25°C. In addition, the degree of crystallinity of the nanoparticles increased rapidly over the same storage period which led to expulsion of DDI nanoparticles for the NLC, despite the DDI loading in NLC being unaffected. It was clearly evident that this new approach of manufacturing solid lipid nanocarriers could be used as a platform not only for enhancing the loading capacity of DDI in solid lipid nanocarriers but also for other hydrophilic drugs. Differential protein adsorption patterns of DDI-loaded NLC were generated in vitro using two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) in order to establish the potential for these systems to deliver DDI to the CNS. NLC formulations containing small amounts of DDI were used as these formulations showed a better stability profile than the formulation with a higher encapsulation efficiency and drug loading capacity. Furthermore, the encapsulation efficiency and drug loading of DDI were considered sufficient for use in 2-D PAGE studies. Data obtained from 2-D PAGE analysis reveal that DDI-loaded NLC preferentially adsorb proteins in vitro that are responsible for specific brain targeting in vivo. More importantly, these studies reveal that in addition to Tween® 80 that has already been shown to have the potential to target CDDS to the brain, Solutol® HS 15 has the potential to achieve a similar objective. Consequently, DDI-loaded NLC have the potential to deliver DDI to the brain and these results may be used as a platform for conducting in vivo studies to establish whether DDI can cross the blood brain barrier and enter the CNS when administered in NLC which may in turn lead to a major breakthrough in the management of HIV/AIDS and Aids Dementia Complex (ADC).

Les enfants infectés par le VIH en Afrique subsaharienne sont exposés à un risque de malnutrition élevé au cours de leur vie. Or, les données sur la nutrition chez ces enfants sont encore limitées en Afrique de l’Ouest. L’objectif global de cette thèse est d’étudier la relation entre nutrition et infection par le VIH, chez les enfants infectés vivant en Afrique de l’Ouest. Plus spécifiquement, il s’agit d’estimer la prévalence de la malnutrition, de décrire l’évolution de la croissance après l’initiation du traitement antirétroviral, et d’évaluer des interventions nutritionnelles à intégrer au sein de la prise en charge pédiatrique du VIH. Les principaux résultats montrent une prévalence élevée de la malnutrition chez ces enfants, proche de 50 % avant la mise sous traitement antirétroviral. L’initiation du traitement a des effets positifs sur la croissance, d’autant plus important que l’initiation se fait de façon précoce. Un déficit pondéral est plus facilement corrigeable qu’un déficit statural, mais une part non négligeable d’enfants continue d’être malnutrie même après deux ans de traitement. En complément du traitement antirétroviral, des interventions de soutien nutritionnel sont donc nécessaires pour lutter contre la malnutrition chez ces enfants. Celles évaluées sont efficaces pour ceux malnutris aigues, mais pas pour ceux avec une malnutrition chronique. De plus, la croissance peut être un marqueur utile de la progression du VIH pédiatrique.L’intégration de la prise en charge nutritionnelle au sein de la prise en charge globale du VIH pédiatrique est possible en Afrique de l’Ouest, mais d’autres études et des actions de plaidoyer sont à développer pour l’adapter au mieux. / HIV-infected children in sub-Saharan Africa are exposed to high risk of malnutrition duringtheir life. However, data on the nutrition of HIV-infected children are still limited in West Africa.Thus, the main objective of this thesis is to better investigate the link between nutrition and HIVinfection among HIV-infected children in West Africa. More specifically, it is aimed to estimate theprevalence of malnutrition, to describe growth evolution after antiretroviral treatment initiation, andto assess proposed nutritional interventions to integrate to pediatric HIV care. The main results showa high prevalence of malnutrition among these children, around 50% before antiretroviral treatmentinitiation. This initiation had positive effects on growth evolution; all the more important whenantiretroviral treatment is early initiated. Weight deficiency is easier to recover than heightdeficiency, but a substantial part of children stay malnourished even after two years of treatment. Inaddition to antiretroviral treatment, nutritional support interventions are needed to fight againstmalnutrition among these children. Those assessed were efficient for acute malnourished children,but not for those with chronic malnutrition. Furthermore, growth could be a useful marker of HIVprogression. Integration of nutritional care into global pediatric HIV care is possible in West Africa,but further studies and advocacy work have to be developed to better adapt it.

Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Kateřina Erbenová Supervisor: PharmDr. Martina Čečková, Ph.D. Title of diploma thesis: Study of interactions antiretroviral drug maraviroc with drug transporters ABCB1 and ABCG2. Maraviroc is inhibitor of CCR5 HIV virus entry into the cells representing one of the important components of antiretroviral therapy. To optimize the treatment strategies and minimize the therapeutic risks of maraviroc-containing combination antiretroviral therapy, it is important to know the interactions of this drug with other antiretrovirals. In particular, interaction on membrane transporters may affect pharmacokinetics and thereby the tissue concentrations of administered drugs, leading to insufficient efficacy of the therapy or increased toxicity. The aim of this study was to experimentally evaluate interaction of maraviroc with the two most important active drug transporters of the ABC transporter superfamily, ABCB1 (P-glycoprotein) and ABCG2 (BCRP). Using in vitro methods employing cell lines we aimed to fulfil two main goals: (1) to evaluate the inhibitory effect of maraviroc on ABCB1 and ABCG2 transporters and (2) to study if any of these transporters could transfer maraviroc as their substrate. The data...

Due to the increasing availability of ART (antiretroviral therapy),HIV is starting to be seen as a chronic disease. This has several effects on families, one of which is the need to disclose their HIV status to children who were born with the illness. Potential barriers and available support structures with regards to paediatric HIV disclosure need to be considered before specific guidelines can be given to caretakers and health care providers. This study aimed to explore and describe the patterns of paediatric HIV disclosure or non-disclosure using a sample of caretakers or parents of children/adolescents who were born with HIV. The Disclosure Decision Making Model (DDMM) was used as a framework to understand the decision-making process that leads to either disclosure or non-disclosure. Qualitative data was gathered by means of in-depth, semi-structured interviews, conducted in English. Ten participants were recruited from a community health care centre that offers HIV counselling and testing in the Nelson Mandela Bay Health District. Data gathered was transcribed and analysed using thematic analysis. Lincoln and Guba’s model was used to determine the trustworthiness of the data. The two themes that emerged from the study were (1) caretakers wish to disclose HIV status to the child but identified barriers to doing this and, (2) caretakers identified factors that helped them to disclose the child’s status. This study provides a more in-depth understanding of the factors that influence disclosure in a resource-limited setting in the Eastern Cape.

Antiretroviral drugs taken during pregnancy, reduce the rates of mother-to-child transmission from 35 percent to as low as 1 to 2 percent (UNAIDS, 2009). In 2002, the Prevention of Mother-to-Child Transmission (PMTCT) programme was implemented in South Africa. Studies on the implementation of the PMTCT programme have shown that understaffed and under-developed health care facilities were key barriers to the provision of PMTCT services (Health Systems Trust, 2002: 6; Skinner et al., 2003). The aim of this study was to assess the challenges experienced by health care workers working in public sector facilities in the Nelson Mandela Metropole after implementation of the dual therapy PMTCT programme. Four areas were investigated: Infrastructure; Drug Supply Management; Clinic Procedures and Staffing. A quantitative descriptive study was conducted in August 2009 at nine public health care facilities in the Nelson Mandela Metropole, South Africa. Questionnaires were issued to 81 nurses and 41 pharmacy personnel (pharmacists and pharmacist assistants). Checklist audit forms were issued to the Facility Manager of each facility and completed with the researcher. The key findings for Infrastructure were lack of space at patient waiting rooms (9; 100 percent n=9), counselling area (5; 55.5 percent; n=9), nurse consultation rooms (6; 66.6 percent; n=9), storage areas (5; 55.5 percent; n=9) and filing areas (7; 77.7 percent; n=9). The key findings for Drug Supply Management were none of the dispensaries (0 percent; n=10) were fully compliant with Good Pharmacy Practice, pharmacy personnel indicated that there were no stock cards for medication (13; 31.7 percent; n=41); there was less than two weeks supply of buffer stock kept for zidovudine and nevirapine (13; 35.1percent; n=37) and medication orders were placed without any reference to minimum and maximum levels of medication (15; 36.5 percent; n=41) . The key findings for Clinic Procedures were only two facilities followed up on patients that had missed appointments (22.2 percent; n=9) and four facilities (44.4 percent; n=9) had a tracking system for patients that had defaulted. Of the nine facilities only three (33.3 percent; n=9) updated patient demographic details regularly. The key findings for Staffing were a shortage of doctors, nurses, counsellors and pharmacists at the facilities. One of the major challenges identified was the lack of training offered on new PMTCT protocols with 56.2 percent (45; n=80) of the nurses stating that no training was provided on the dual PMTCT protocol. Only 54.3 percent (44; n=81) of nurses stated that they knew the criteria to start the mother on dual PMTCT therapy. In conclusion there is an urgent need for barriers such as lack of staff, lack of space, lack of training on PMTCT and standard procedures for follow up of patients to be addressed in order to ensure the successful scaling up of PMTCT.

The Human Immunodeficiency Virus (HIV)/Acquired Immune Deficiency Syndrome (AIDS) is one of the leading chronic diseases affecting people in South Africa and throughout the world. This study aimed to investigate the effect disclosure of HIV status had on antiretroviral therapy (ART) adherence. A convenience sample of 65 HIV positive adult patients currently taking ART at a public Primary Health Care (PHC) clinic in the Nelson Mandela Metropole was selected. Participation was voluntary and confidentiality was maintained at all times. Data was collected using three tools/techniques: (1) a Patient Questionnaire (PQ) to extract information on patient's demographics, HIV disclosure status, regimen the patient was on and self-reported adherence to ART; (2) an audit of a Patient Medical Record (PMR) for information on the regimen the patient was on, the period during which the patient had been on ART medication, the adherence to ART care and the level of the patient‟s biological markers; and (3) Pill Counts (PC) performed on the patient's medical supply to validate the self-reported adherence to ART. There was no significant relationship between the disclosure of HIV status and adherence to ART (p= 0.59; Chi²). However, the relationship between the adherence to ART and increase in the CD4 count levels of patients on ART in this population was significant (p=0.03; Chi²). It can be concluded that no direct relationship was found between the disclosure of HIV status and adherence to ART in this population. However, several factors affected the reasons and decisions of individuals to disclose their HIV status and this influenced their daily taking of medication.

The socio-economic impact of HIV/AIDS on South Africa has resulted in lower gross domestic product, loss of skills in key sectors such as education, and increased health-care costs in providing access to treatment. Currently active pharmaceutical ingredients (API’s) such as stavudine (d4T) and azidothymidine (AZT) are imported from India and China, while formulation is conducted locally. A strategy was initiated between CSIR Biosciences and LIFElab under the auspices of Arvir Technologies to investigate the feasibility of local antiretroviral manufacture (d4T and AZT) or the manufacture of a key intermediate such as β- thymidine (dT). Several advantages associated with successful implementation of this strategy include ensuring a local supply of API’s, thus reducing reliance on procurement from foreign sources and reducing the effect of foreign exchange rate fluctuations on providing cost effective access to treatment. A local supply source would also reduce the imports and thus aid the balance of payments deficit, and in addition to this, provide stimulus in the local pharmaceutical manufacturing industry (which has been in decline for several decades), resulting in increased skills and employment opportunities. This thesis describes the development of a superior chemo-enzymatic process for the production of β-thymidine (72 percent yield, prior to isolation), a key intermediate in the preparation of anti-retrovirals. Alternative processes based purely on chemical or bioprocess transformations to prepare either 5-methyluridine (5-MU) or dT suffer from several disadvantages: lengthy transformations due to protection/deprotection strategies, low selectivties and product yields (30 percent in the chemical process) and isolation of the product from dilute process streams requiring the use of large uneconomical reactors (bioprocesss). This contributes significantly to the cost of d4T and AZT manufacture. Our novel chemoenzymatic process comprises of a biocatalytic reaction for the production of 5-MU, with subsequent chemical transformation into dT (3 steps) negating and circumventing the limitations of the chemical or bioprocess routes. During the course of this project development, the β-thymidine selling price declined from 175 $/kg (2005) to 100 $/kg (2008). However, the process described in this work is still competitive based on the current β- thymidine selling price of 100 $/kg. The process economics show that with further optimization and increasing the isolated dT yield from 70 percent to 90 percent, the variable cost decreases from 136 $/kg to 110 $/kg. The increase in isolated yield is highly probable, based on solubility data of β-thymidine. The decrease in β-thymidine selling price and technological improvement in dT manufacture should translate into lower API manufacture costs and more cost effective access to treatment. Our novel biocatalytic process producing 5-MU uses a coupled enzyme system employing PNP, Purine Nucleoside Phosphorylase and PyNP, Pyrimidine Nucleoside Phosphorylase. The overall transglycosylation reaction may be decoupled into the phosphorolysis reaction (PNP) and synthesis reaction (PyNP). During the phosphorolysis reaction, guanosine is converted into guanine and ribose-1-phosphate (R-1-P) in the presence of PNP enzyme. The reaction intermediate R-1-P is then coupled to thymine in the presence of PyNP enzyme during the synthesis reaction, producing 5-MU. The process was scaled up from lab-scale to bench-scale (10 - 20 L) and demonstrated to be robust and reproducible. This is evident from the average guanosine conversion (94.7 percent ± 2.03) and 5-MU yield (88.2 percent ± 6.21) and mole balance (104 percent ± 7.61) which were obtained at bench-scale (3 replicates, 10 L). The reaction was carried out at reactor productivities of between 7 – 11 g.L-1.h-1. The integration of the biocatalytic process and chemical processes was successfully carried out, showing that 5-MU produced using our novel biocatalytic process behaved similarly to commercially available 5- MU (ex. Dayang Chemicals, China). A PCT patent application (Ref. No. P44422PC01) on this chemo-enzymatic process has been filed and currently public private partnerships are being explored through Arvir Technologies to evaluate and validate this technology at one ton scale.

This study aimed to explore and describe the quality of life of adolescents living with early childhood HIV infection on Highly Active Antiretroviral Therapy (HAART) in Port Elizabeth. The advent of HAART has resulted in HIV being managed as a chronic illness, instead of the fatal disease that it once was. Children born with HIV can now live longer lives, progressing to adolescence and beyond. Chronic illness is known to impact one’s quality of life, so does adolescent development. A convenient sample of 31 adolescents was used in this study, with an exploratorydescriptive research design. The data was gathered using a cross cultural structured questionnaire developed by the World Health Organization, as well as through individual interviews. The data was then analysed by means of descriptive statistics and thematic content analysis. The results identified and presented the quality of life issues that are specific to this population. The results indicate that HIV as a chronic illness does impact the quality of life of adolescents. The adolescents living with early childhood HIV-infection on HAART in this study were very satisfied with their perceptions of their overall quality of life and general health perceptions. They were least satisfied in the Spirituality/Religion/Personal Beliefs and Social Relationships domains; and were most satisfied in the Level of Independence and the Psychological domains. There is a need for the development of (medical and psychosocial) services that can focus on adolescents as a special population with specific developmental needs in order to improve their treatment outcomes and quality of life.