ETD Collection

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Subject: search.filters.subject.Human Immunodeficiency Virus

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    In-vivo dynamics of HIV-1 evolution
    (2011-09-14) Shiri, Tinevimbo;
    The evolution of drug resistance in human immunodeficiency virus (HIV) infection has been a focus of research in many fields, as it continues to pose a problem to disease prevention and HIV patient management. In addition to techniques of molecular biology, studies in mathematical modelling have contributed to the knowledge here, but many questions remain unanswered. This thesis explores the application of a number of hybrid stochastic/deterministic models of viral replication to scenarios where viral evolution may be clinically or epidemiologically important. The choice of appropriate measures of viral evolution/diversity is non-trivial, and this impacts on the choice of mathematical techniques deployed. The use of probability generating functions to describe mutations occurring during early infection scenarios suggest that very early interventions such as pre-exposure prophylaxis (PrEP) or vaccines may substantially reduce viral diversity in cases of breakthrough infection. A modified survival analysis coupled to a deterministic model of viral replication during transient and chronic treatment helps identify clinically measurable indicators of the time it takes for deleterious rare mutations to appear. Lastly, persistence of problematic mutations is studied through the use of deterministic models with stochastic averaging over initial conditions.
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    Estimating the incidence of acute HIV infection from a single cross-sectional sample
    (2011-09-14) Akindolani, Omotola Omokunbi
    The Human Immunodeficiency Virus (HIV) epidemic is currently one of the greatest challenges and most important health issues in the world. South Africa has one of the fastest growing epidemics in the world therefore reliable estimates of prevalence and incidence are required for understanding the magnitude of the epidemic and improving the methods of prevention. This study examines the estimation of HIV incidence from a cross-section of people, using one of the laboratory methods that discover recent HIV infection in blood samples. The incidence estimate is obtained at a single point in time, thereby saving time and cost expended in following a cohort over a period of time. It also examines incidence from pooled blood samples, and evaluates the assumptions of the different methods of estimating HIV incidence, comparing each of them; and checking the sensitivity of the estimates to the assumptions. Results from the simulation study shows that accurate estimates of incidence can be obtained by pooling blood samples; and these estimates are obtained at a fraction of the cost of individual testing.
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    Knowledge levels of voluntary counselling and testing for human immunodeficiency virus amoungst taxi drivers in Kampala, Uganda
    (2007-02-28T12:12:53Z) Kizito, Assisi-Franklin
    Introduction: Human Immunodeficiency Virus (HIV) was first isolated from human blood in 1983 at the Pasteur Institute, Paris. Currently there is no cure for HIV and control efforts emphasize prevention. One of the components of the Global Strategy put forward to preventing HIV transmission is HIV Voluntary Counselling and Testing (VCT) (Ginwalla, Grant & Day:2002). Taxi drivers are part of the Ugandan population at special risk of acquiring this virus. It was therefore necessary to carry out a study in this group of people to assess how much they knew about HIV/VCT services. Study Objectives To establish the level of knowledge amongst the taxi drivers about the availability and accessibility of HIV VCT services in Kampala. To identify factors that influence the taxi drivers in Kampala, Uganda to access the VCT services. Methods and materials A cross-sectional descriptive study design was used to carry out the study amongst 400 taxi drivers who consented to participate and operated within and around the city of Kampala during 2004. A structured questionnaire to record variables that included, age, sex, marital status, level of education, level of knowledge of VCT, factors that enhance VCT uptake, factors that inhibit VCT uptake, history of having ever had VCT, and knowledge of spouse or sexual partner’s HIV serostatus, was used. Data was entered into EPI-INFO 6 computer program and descriptive and analytic investigation using proportion or percentages to compare the level of knowledge generated was used. Findings/Results A total of 399 taxi drivers with 52.8% of them aged between 26 – 35 years participated in the study. 68.8% lived within 6 km of the city centre. All were married and 78.8% had one spouse. 0.75% were lady drivers. 55% of the participants had attained secondary school level of education. 69% of the taxi drivers knew that HIV/AIDS was the commonest health problem in the country and 57.4% of the participants mentioned HIV testing as the only way one would ascertain their serostatus. 94.2% had heard about HIV/VCT mainly from the media and as much as 98.7% of the taxi drivers knew a place where such services could be got. 82.2% confirmed that these places were accessible and 85.9% said that the services were not expensive. However, 57.3% of the participants preferred getting these services where they were known in order to get genuine results and subsequent support. The 26% who opposed this idea sighted confidentiality as the main obstacle. Despite the knowledge level about HIV/VCT amongst the participants, 68.3% of the communal taxi drivers were willing to go for the service and only 16.1% had actually taken the test. Out of the 399 participants 59.6% felt that they could share their serostatus with their spouses. Conclusion The taxi drivers are knowledgeable about HIV/VCT services and these findings lie within the overall range of knowledge of the population in urban Uganda. The HIV/VCT services are accessible and affordable to the taxi drivers but the fear to receive the unexpected results and the consequences of having positive results hinder the taxi drivers from seeking the VCT services. The majority of taxi drivers preferred to go to HIV/VCT service points where they were known. This factor could have contributed to the small number of taxi drivers that had taken the test. Probably few suitable service points to go to had been identified by these taxi drivers. Recommendations The government and other organizations that provide care in the field of HIV should organize sensitization seminars for taxi drivers to address issues aimed at allaying their anxiety or fear to receive positive results. Also, there is a need to intensify counselling services for the taxi drivers by establishing counselling centres close to the two taxi parks in the City. HIV/VCT service centres should be integrated with other health services so that people who seek either of the services can gain from both. This will encourage more taxi drivers to come to these centres.