Thesis (MNutr (Interdisciplinary Health Sciences. Human Nutrition))--Stellenbosch University, 2008. / Introduction: More than half a million children worldwide die from the Human Immunodeficiency Virus (HIV) and Acquired Immunodeficiency Syndrome (AIDS) each year. In Uganda, HIV/AIDS is a major cause of infant and childhood mortality. Although the government of Uganda, through various strategies, has increased access to antiretroviral drugs (ARVs), resulting in national scaling up of accessibility to antiretroviral therapy (ART), initiation of ART in resource-limited areas remains a challenge due to constraints such as the absence of or limited number of CD4 machines and related laboratory constraints. Further scaling up of ART for children would be greatly strengthened by increased access to laboratory services for CD4 counts or the introduction of alternative indicators or guidelines for the initiation of ART. Aim: This study therefore set out to investigate, through the analysis of retrospectively collected data, whether anthropometric indices (wasting - weight for height; underweight - weight for age; and stunting - height for age) could provide a useful alternative guide when deciding about initiation of ART in children aged 2-12 years in the absence of sophisticated clinical and laboratory support. Methods: The study was conducted at the Mildmay Centre, an HIV/AIDS specialist centre located in Kampala, Uganda. Parameters such as the age at which children had been initiated onto ART, duration on ART, World Health Organisation (WHO) and Centre for Disease Control (CDC) disease stages at time of initiation, anthropometry at time of initiation, CD4% staging at time of initiation, support received from food aid programmes, referral to other health centres as a result of malnutrition and care-giver nutrition education/counselling were all determined retrospectively from clinical records. Results: It was found, based on CDC (2000) growth reference charts, that of the total number of children who took part in this study (N=125), 98.4% were mildly wasted, 52.8% mildly underweight and 75.2% mildly stunted when they were initiated onto ART. Of the children, who had WHO disease staging documented - 40% (N=50), the majority - 86% (N=43) were in WHO disease staging II and III during initiation of ART. and 96% (N=48) were mildly wasted. However, the relationship between WHO disease staging and wasting, underweight, and stunting at initiation of ART in children at the Mildmay centre was not significant. The relationship between CD4% and underweight or stunted children was also not significant. It was established however, that in the absence of CD4 laboratory parameters (since CD4% is vital in the initiation of ART in children) as is the case in resource limited areas, anthropometric indices (moderate to severe wasting, weight for height -W/H) could be used concurrently with CDC and WHO disease staging to initiate ART in children. However, it is important to note that anthropometric indices on their own cannot be used as a guide for initiating ART in children. Conclusion: Anthropometric status alone cannot be used to accurately determine when to initiate ART in children 2-12 years.

Magister Pharmaceuticae - Mpharm / Many studies have investigated the pharmacokinetics (PK) of anti-tuberculosis drugs in tuberculosis patients. However, currently in South Africa, no studies have been done on ethionamide (ETH) PK in adult MDR-TB patients that are infected with HIV and those without HIV infection. Therefore, the objective of this current study was firstly, to find out ethionamide plasma concentration using the LC-MS method; secondly, to evaluate and compare the pharmacokinetics of ethionamide in MDR-TB patients infected with and without HIV infection; thirdly, to examine the effects of ARVs and kidney impairment on the PK of ethionamide and fourthly, to find out the consequence of sex and age on ETH PK parameters.

This study sought to explore the views of healthcare workers regarding paediatric anti-retroviral therapy (ART) adherence in Nigeria. An exploratory descriptive qualitative research design was used to identify and describe healthcare workers’ views in Kano and Lagos, Nigeria. Three focus group discussions were held. The transcribed data was analysed using the framework approach of data analysis. Healthcare providers perceived poverty, illiteracy, stigma and discrimination, inappropriate care approaches, and parental dynamics as factors influencing ART adherence. Recommendations for enhancing paediatric ART adherence levels in Nigeria included: mainstreaming adherence counselling in paediatric ART and adopting a comprehensive family centred care approach were identified as measures for improving paediatric ART adherence. Other measures included free ART services, quality improvement in paediatric ART services, parental empowerment and stigma and discrimination reduction programmes. / Health Studies / M.A. (Public Health)

The objective of this study was to assess levels of HAART adherence and factors affecting it. An observational, analytic, cross-sectional and quantitative study using IMB model was conducted on a randomly selected 349 HIV/AIDS patients on a HAART regimen. Data collection was done by interviewing respondents using a structured questionnaire. Both descriptive and inferential statistics used in the study. Only 80.2% of the total sample population reported a HAART adherence rate of more than or equal to 95% in this study. The findings highlight the need for on-going educational, informational and other interventions to address the knowledge, motivation and adherence behavioural skills of patients in order to improve the current levels of HAART adherence behaviour. The study also suggested the need for research into objective measures of adherence as well as longitudinal studies on adherence behaviour because strict adherence to treatment is a long-term process and not a one-time activity. / Health Studies / M.A. (Public health)

Health Studies / (M.P.H. (Health Studies))

The introduction of antiretroviral drugs (ARVs) in 1996 transformed the treatment of HIV and AIDS, improving the quality and greatly prolonging the lives of many infected people. HIV (Human Immunodeficiency Virus) is the virus that is believed to cause AIDS. AIDS (Acquired Immune Deficiency Syndrome) is the collection of illnesses or symptoms that ultimately results in death. Antiretroviral (ARVs) drugs or Highly Active Antiretroviral Therapy (HAART) is the treatment that has been applied to combat the HI virus in a bid to slow down the progression of AIDS and ultimately prolong the life of the infected individual. The study aimed to explore and describe the factors contributing to adherence and non-adherence to ARVs in individuals on treatment. A sample of 81 individuals who have been on ARV and HAART treatment for six months or more was used. The methodology used was exploratory-descriptive and the data obtained was quantitative in nature. A biographical questionnaire and questionnaire with questions aimed at ascertaining the possible factors that contribute to individuals either adhering to or defaulting on their treatment, such as side effects and cost of treatment, was administered. The data obtained was analysed by means of descriptive statistics and frequency counts. The results of the study showed that the sample had a fairly high level of adherence. The factors that could undermine adherence were identified as lack of support, as familial and health provider support acts as a motivator to adhere; substance abuse as it can lead to forgetting to take treatment; unemployment and poverty, as these can lead to an inability to return for follow up clinic visits or failure to have food to take with the pills; and the type of treatment regimen whereby the more complex the treatment is the more likely it is that adherence will be difficult to maintain. Suggestions were made as to future research involving antiretroviral therapy (ART). Finally the limitations as well as the value of the research were outlined.

Approximately 33.4 million people are living with HIV/AIDS. Of those, 97% live in low and middle income countries, with 22.4 million in sub-Saharan Africa. Only 42% of the people who require anti-retrovirals (ARVs) in low to middle income countries are receiving anti-retroviral therapy (ART). There is a need to develop novel and cost effective methods for producing antiretroviral drugs. Stavudine and azidothymidine (AZT) were identified as potential targets because they could both be produced through a common intermediate – 5 methyluridine (5-MU). It has been established that the biocatalytic production of 5-methyluridine is possible through a reaction known as transglycosylation, in a process which has not previously been demonstrated as commercially viable. A selection of biocatalysts were expressed either in recombinant E. coli strains or in the wild type organisms, purified and then screened for their ability to produce 5-MU. A combination of Bacillus halodurans purine nucleoside phosphorylase 1 (BHPNP1) and E. coli uridine phosphorylase (EcUP) gave the highest 5-MU yield (80%). This result represents the first combination of free enzymes from different organisms, giving high yields of 5-MU under high substrate conditions. Both enzymes were purified and successfully characterised. The established pH optimum was pH 7.0 for both enzymes. Temperature optima and stability data for BHPNP1 (70 C and t1/2 at 60 C of 20.8 h) indicated that the biocatalytic step was operating within the capabilities of this enzyme and would operate well at elevated temperatures (up to 60 C). Conversely, the temperature optimum and stability data for EcUP (optimum of 40 C and t1/2 at 60 C of 9.9 h) indicated that the enzyme remained active at 40 C for the duration of a 25 h biotransformation, but at 60 C would only be operating at 20% of its optimum activity and would lose activity rapidly. BHPNP1 and EcUP were used in a bench scale (650 ml) transglycosylation for the production of 5-MU. A 5-MU yield of 79.1% was obtained at this scale with a reactor productivity of 1.37 g.l-1.h-1. Iterative saturation mutagenesis was used to rapidly evolve EcUP for improved thermostability. A moderately high throughput colorimetric method was developed for screening the mutants based on the release of p-nitrophenol upon phosphorolysis of a pyrimidine nucleoside analogue. By screening under 20 000 clones the mutant UPL8 was isolated. The mutant enzyme showed an optimum temperature of 60 C and improved stability at 60 C (t1/2 = 17.3 h). The increase in stability of UPL8 is due to only 2 mutations (Lys235Arg, Gln236Ala). These mutations may have caused an increase in stability due to interactions with other structural units in the protein, stabilization of the entrance to the binding pocket, or by decreasing the flexibility of the α-helix at the N-terminus. Transglycosylation experiments showed that the mutant enzyme UPL8 is a superior catalyst for the production of 5-MU. A 300% increase in reactor productivity was noted when free enzyme preparations of UPL8 was combined with BHPNP1 at 1.5% m.m-1 substrate loading. The high yield of 5-MU (75-80% mol.mol-1) was maintained at 9% m.m-1 substrate loading. A commercially viable productivity of 31 g.l-1.h-1 was thus realised. Further optimisation of the process could produce still higher productivities. Future work in directed evolution of nucleoside phosphorylases is envisaged for improved stability and enhanced substrate range for application to other commercially relevant transglycosylation reactions.

The Human Immunodeficiency Virus (HIV) and Acquired Immuno Deficiency Syndrome (AIDS) epidemic has had massive detrimental impacts on rural communities across Africa including in Zimbabwe. In response to the HIV and AIDS epidemic, the government of Zimbabwe has developed and adopted comprehensive programmes to address HIV and AIDS prevention, care and support. One of the critical components of these programmes relates specifically to treatment of the HIV infected given that HIV and AIDS is increasingly seen as a manageable threatening disease. However the success and effectiveness of the treatment regimen (involving antiretroviral drugs or ARVs) is dependent heavily on complete adherence to the rigid and complex regimens. It is against this background that this thesis studies a particular rural community in Zimbabwe called Chivanhu (in Masvingo Province) in terms of the relationship between rural livelihoods and HIV and AIDS (particularly HIV treatment and treatment adherence). Unlike other rural communities (notably in communal areas), Chivanhu is an informal and unstable community with a turbulent history. Most rural studies of HIV and AIDS in Zimbabwe and elsewhere in the region have focused on well-established and stable communities in which agricultural production is still of some significance. In such communities, the impact of HIV and AIDS on livelihoods is severe but, in more informal settlements, the vulnerability of households to the epidemic (and challenges pertaining to treatment adherence) is even more pronounced. Using a rural livelihoods framework, this thesis seeks to identify, understand and analyse the conditions which shape levels of adherence to HIV and AIDS in the informalsettlement of Chivanhu in Zimbabwe.

Despite the current interventions to avert contagions and AIDS-related deaths, sub-Saharan Africa is still the region most severely affected by the HIV/AIDS pandemic, where clade C is the dominant circulating HIV-1 strain. The pol-encoded HIV-1 protease enzyme has been extensively exploited as a drug target. Protease inhibitors have been engineered within the framework of clade B, the commonest in America, Europe and Australia. Recent studies have attested the existence of sequence and catalytic disparities between clades B and C proteases that could upset drug susceptibilities. Emergence of drug-resistant associated mutations and combinatorial explosions due to recombination thwarts the attempt to stabilize the current highly active antiretroviral therapy (HAART) baseline. The project aimed at identifying the structural and molecular mechanisms hired by mutants to affect the efficacies of both FDA approved and Rhodes University (RU)-synthesized inhibitors, in order to define how current and or future drugs ought to be modified or synthesized with the intent of combating drug resistance. The rationale involved the generation of homology models of the HIV-1 sequences from the South African infants failing treatment with two protease inhibitors: lopinavir and ritonavir (as monitored by alterations in surrogate markers: CD4 cell count decline and viral load upsurge). Consistent with previous studies, we established nine polymorphisms: 12S, 15V, 19I, 36I, 41K, 63P, 69K, 89M, and 93L, linked to subtype C wild-type; some of which are associated with protease treatment in clade B. Even though we predicted two occurrence patterns of M46I, I54V and V82A mutations as V82A→I54V→M46I and I54V→V82A→M46V, other possibilities might exist. Mutations either caused a protracted or contracted active site cleft, which enforced differential drug responses. The in silico docking indicated susceptibility discordances between clades B and C in certain polymorphisms and non-polymorphisms. The RU-synthesized ligands displayed varied efficacies that were below those of the FDA approved protease inhibitors. The flaps underwent a wide range of structural motions to accommodate and stabilize the ligands. Computational analyses unravelled the need for these potential drugs to be restructured by (de novo) drug engineers to improve their binding fits, affinities, energies and interactions with multiple key protease residues in order to target resilient HIV-1 assemblages. Accumulating evidences on contrasting drug-choice interpretations from the Stanford HIVdb should act as an impetus for the customization of a HIVdb for the sub-Saharan subcontinent.

Pharmacological interventions to treat Human Immunodeficiency Virus (HIV) with antiretrovirals (ARVs), have dramatically improved the survival rates of HIV positive children maturing into adulthood. However, HIV-associated neurocognitive decline still persists in the era of ARVs. Within the framework of brain plasticity, a number of researchers have begun to assess the feasibility of cognitive rehabilitation therapy as a complement to ARVs to reverse neurocognitive decline as a result of HIV (e.g., Becker et al., 2012). Only one study has been conducted in South Africa, by Zondo & Mulder (2014), assessing the efficacy of cognitive rehabilitation in a paediatric sample. The current research builds on the above mentioned study by implementing an experimental approach to examine the effect of cognitive rehabilitation in a sample of both HIV positive and HIV negative children. Five HIV positive and six HIV negative children were assigned to either an experimental or control group. The experimental group underwent two months of cognitive rehabilitation therapy remediating sustained attention, whereas the control group took part in placebo activities. Sustained attention measures were taken before and after the intervention training sessions, using a sustained attention subtest from the Test of Everyday Attention for Children (TEA-CH). A Mann Whitney U Test revealed that the experimental group (Mdn=38.50) did not differ significantly from the control group (Mdn = 37.00) after the cognitive rehabilitation intervention, U=12.00, z= -.55, p= .66, r= -.17. But a Wilcoxon Signed Rank Test found that there was a significant improvement from pretest scores (Mdn=31.00) to posttest scores (Mdn=38.00) following the rehabilitation for HIV positive participants in the sample, T=15.00, z = -2.02, p= .04, r= -.90. This raises the possibility that cognitive rehabilitation could be used as a low cost intervention in underdeveloped contexts