Thesis (DTech (Mechanical Engineering))--Cape Peninsula University of Technology, 2012 / In this thesis, we investigate certain key aspects of mathematical modelling to explain the epidemiology of HIV/AIDS at the workplace and to assess the potential benefits of proposed control strategies. Deterministic models to investigate the effects of the transmission dynamics of HIV/AIDS on labour force productivity are formulated. The population is divided into mutually exclusive but exhaustive compartments and a system of differential equations is derived to describe the spread of the epidemic. The qualitative features of their equilibria are analyzed and conditions under which they are stable are provided. Sensitivity analysis of the reproductive number is carried out to determine the relative importance of model parameters to initial disease transmission. Results suggest that optimal control theory in conjunction with standard numerical procedures and cost effective analysis can be used to determine the best intervention strategies to curtail the burden HIV/AIDS is imposing on the human population, in particular to the global economy through infection of the most productive individuals. We utilise Pontryagin’s Maximum Principle to derive and then analyze numerically the conditions for optimal control of the disease with effective use of condoms, enlightenment/educational programs, treatment regime and screening of infectives. We study the potential impact on productivity of combinations of these conventional control measures against HIV. Our numerical results suggest that increased access to antiretroviral therapy (ART) could decrease not only the HIV prevalence but also increase productivity of the infected especially when coupled with prevention, enlightenment and screening efforts.

Adolescence is a significant period of change in physical and psychosocial development of human beings. Being HIV positive and growing up on a dynamically multifaceted HAART treatment, adds to the complexity of adolescence. This study was aimed at exploring the nature of experiences of adolescents who are on long-term Highly Active Antiretroviral Therapy (HAART) in Tembisa, Gauteng province. The study is based on a qualitative research method using in-depth semi-structured open-ended interviews and a focus group for data collection. The sample consisted of seven individual adolescent participants, three parents, guardians and caregivers, as well as 11 health care professionals. The thematic data analysis and the phenomelogical analysis methods were used to analyse data qualitative data while descriptive statistics were used to analyse quantitative biographical data. The study findings cover the negative and positive experiences and the perceived role of HAART treatment over a long period of time. The predominant themes identified from adolescent participants were disclosure of HIV positive status and the stigma surrounding a positive status, early childhood experience of parental death, challenges of taking HAART treatment, factors influencing adherence and non-adherence to HAART treatment, and lastly, the impact of religion on HAART treatment adherence. The findings suggest that adolescents who are on HAART treatment over an extended period of time experience drug fatigue. Drug fatigue has far-reaching implications for the health of an adolescent, as it has a higher likelihood that poor adherence or even complete refusal to take HAART treatment will occur. Poor adherence or refusal to take HAART treatment will most likely lead to cross infection and further spread of HIV and AIDS. A recommendation was made to include the establishment of a youth and adolescent-friendly centre by the hospital – one that is designated for the provision of tailored adolescent services and sensitive to adolescent developmental stages so as to minimise the likelihood of infected adolescents falling through the health care cracks. The introduction of a hospital-based school, an education unit run by dedicated and qualified facilitators focusing on aiding hospitalised learners with catch-up scholarly programmes, was a further recommendation. It was further recommended that reproductive health care needs of adolescents who grow up on HAART treatment be given attention in further research. / Psychology / Ph.D. (Psychology)