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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Construction and analysis of efficient numerical methods to solve mathematical models of TB and HIV co-infection

Ahmed, Hasim Abdalla Obaid January 2011 (has links)
<p>The global impact of the converging dual epidemics of tuberculosis (TB) and human immunodeficiency virus (HIV) is one of the major public health challenges of our time, because in many countries, human immunodeficiency virus (HIV) and mycobacterium tuberculosis (TB) are among the leading causes of morbidity and mortality. It is found that infection with HIV increases the risk of reactivating latent TB infection, and HIV-infected individuals who acquire new TB infections have high rates of disease progression. Research has shown that these two diseases are enormous public health burden, and unfortunately, not much has been done in terms of modeling the dynamics of HIV-TB co-infection at a population level. In this thesis, we study these models and design and analyze robust numerical methods to solve them. To proceed in this direction, first we study the sub-models and then the full model. The first sub-model describes the transmission dynamics of HIV that accounts for behavior change. The impact of HIV educational campaigns is also studied. Further, we explore the effects of behavior change and different responses of individuals to educational campaigns in a situation where individuals may not react immediately to these campaigns. This is done by considering a distributed time delay in the HIV sub-model. This leads to Hopf bifurcations around the endemic equilibria of the model. These bifurcations correspond to the existence of periodic solutions that oscillate around the equilibria at given thresholds. Further, we show how the delay can result in more HIV infections causing more increase in the HIV prevalence. Part of this study is then extended to study a co-infection model of HIV-TB. A thorough bifurcation analysis is carried out for this model. Robust numerical methods are then designed and analyzed for these models.&nbsp / Comparative numerical results are also provided for each model.</p>
52

Therapeutic and virological outcomes in adults living with HIV / AID at 6 and 12 months after initiation of first-line highly active antiretroviral therapy in an urban population in Namibia

Vivianne Inganai Gorova January 2010 (has links)
<p>Antiretroviral regimens have side effects that can threaten adherence by patients resulting in evolution of viral resistance due to suboptimal drug levels. Studies have shown that drug adherence of at least 80% can result in viral load suppression. There is no literature on the association between the level of adherence to antiretroviral therapy and the degree of virological suppression in Namibia. The aim of the present study was to determine the therapeutic and virological outcomes in HIV/AIDS patients at 6 and 12 months after initiation of highly-active antiretroviral therapy (HAART) in an urban population in Namibia. The distribution of viral load results showed a low uptake (35%) of virological monitoring at 6 month time point and even lower (12%) at 12 months. A conservative viral load threshold for virological response is required in the Namibian setting. The current adherence level of &gt / 80% encourage increased ARV therapy rollout. Poor virological outcome was associated with self-reported adherence.</p>
53

Construction and analysis of efficient numerical methods to solve mathematical models of TB and HIV co-infection

Ahmed, Hasim Abdalla Obaid January 2011 (has links)
<p>The global impact of the converging dual epidemics of tuberculosis (TB) and human immunodeficiency virus (HIV) is one of the major public health challenges of our time, because in many countries, human immunodeficiency virus (HIV) and mycobacterium tuberculosis (TB) are among the leading causes of morbidity and mortality. It is found that infection with HIV increases the risk of reactivating latent TB infection, and HIV-infected individuals who acquire new TB infections have high rates of disease progression. Research has shown that these two diseases are enormous public health burden, and unfortunately, not much has been done in terms of modeling the dynamics of HIV-TB co-infection at a population level. In this thesis, we study these models and design and analyze robust numerical methods to solve them. To proceed in this direction, first we study the sub-models and then the full model. The first sub-model describes the transmission dynamics of HIV that accounts for behavior change. The impact of HIV educational campaigns is also studied. Further, we explore the effects of behavior change and different responses of individuals to educational campaigns in a situation where individuals may not react immediately to these campaigns. This is done by considering a distributed time delay in the HIV sub-model. This leads to Hopf bifurcations around the endemic equilibria of the model. These bifurcations correspond to the existence of periodic solutions that oscillate around the equilibria at given thresholds. Further, we show how the delay can result in more HIV infections causing more increase in the HIV prevalence. Part of this study is then extended to study a co-infection model of HIV-TB. A thorough bifurcation analysis is carried out for this model. Robust numerical methods are then designed and analyzed for these models.&nbsp / Comparative numerical results are also provided for each model.</p>
54

Analysis and implementation of robust numerical methods to solve mathematical models of HIV and Malaria co-infection

Elsheikh, Sara Mohamed Ahmed Suleiman January 2011 (has links)
There is a growing interest in the dynamics of the co-infection of these two diseases. In this thesis, firstly we focus on studying the effect of a distributed delay representing the incubation period for the malaria parasite in the mosquito vector to possibly reduce the initial transmission and prevalence of malaria. This model can be regarded as a generalization of SEI models (with a class for the latently infected mosquitoes) and SI models with a discrete delay for the incubation period in mosquitoes. We study the possibility of occurrence of backward bifurcation. We then extend these ideas to study a full model of HIV and malaria co-infection. To get further inside into the dynamics of the model, we use the geometric singular perturbation theory to couple the fast and slow models from the full model. Finally, since the governing models are very complex, they cannot be solved analytically and hence we develop and analyze a special class of numerical methods to solve them.
55

Construction and analysis of efficient numerical methods to solve Mathematical models of TB and HIV co-infection

Ahmed, Hasim Abdalla Obaid. January 2011 (has links)
In this thesis, we study these models and design and analyze robust numerical methods to solve them. To proceed in this direction, first we study the sub-models and then the full model. The first sub-model describes the transmission dynamics of HIV that accounts for behavior change. The impact of HIV educational campaigns is also studied. Further, we explore the effects of behavior change and different responses of individuals to educational campaigns in a situation where individuals may not react immediately to these campaigns. This is done by considering a distributed time delay in the HIV sub-model. This leads to Hopf bifurcations around the endemic equilibria of the model. These bifurcations correspond to the existence of periodic solutions that oscillate around the equilibria at given thresholds. Further, we show how the delay can result in more HIV infections causing more increase in the HIV prevalence. Part of this study is then extended to study a co-infection model of HIV-TB. A thorough bifurcation analysis is carried out for this model. Robust numerical methods are then designed and analyzed for these models. Comparative numerical results are also provided for each model.
56

An assessment of knowledge of HIV/AIDS amongst secondary school learners of Kwazulu-Natal: an exploratory study of Bergville rural district

Maleka, Nelisiwe Elma January 2009 (has links)
<p>The main purpose of the study was to assess and explore the knowledge of HIV/AIDS among secondary learners in rural Bergville district of KwaZulu-Natal. A stratified random sample of 100&nbsp / learners was selected from two secondary schools in the area. Data was collected using a questionnaire and interviews were scheduled with the teachers from the selected schools. The&nbsp / questionnaire was administered to a sample of 54 learners from school A and 46 from school B. The mean age was 16, with age range from 13-20. The participants were enrolled for grade&nbsp / 8-12 in both schools. Both qualitative and quantitative data on learners‟ knowledge and perception about HIV/AIDS, condom use and sexual issues including their attitudes towards people living with HIV/AIDS were collected in the questionnaire. Chi-square test was used for statistics purpose to test if the HIV knowledge of learners were associated with gender, culture and&nbsp / religion. Qualitative interviews with 9 teachers from both schools were conducted. The main purpose of the interviews was to investigate the management of HIV/AIDS in public schools in rural&nbsp / areas. Furthermore, to assess the learner‟s attitude towards HIV/AIDS education provided in schools. The results showed that the learners in Bergville district were more knowledgeable of&nbsp / HIV/AIDS through HIV/AIDS education in schools that had limited effect on gender, culture and religion. Quantitative findings presented, indicated no significant differences between those&nbsp / learners attending church and cultural activities that offer&nbsp / HIV/AIDS awareness programmes and those who do not with regard to the knowledge of HIV/AIDS. However, culture stood out to be associated with one item on the knowledge of whether school children can get HIV/AIDS (p-value = 0.04). On average, the level of knowledge of HIV/AIDS between female and male learners was similar. The major findings on both quantitative and qualitative findings confirmed that learners‟ knowledge levels were very high for modes of transmission and prevention of HIV/AIDS. Despite this knowledge, poor&nbsp / behavioural change among learners is a major setback thus increasing high risk of contracting HIV. Adequate knowledge about issues of cure, HIV testing and treatment was of concern in the findings in this study. Furthermore, data from qualitative interviews with the teachers highlighted the lack of multisectoral response to HIV/AIDS in Bergville rural communities which thus&nbsp / compromise the effectiveness in management of HIV/AIDS in schools. In summary, the study revealed some of the challenges faced by teachers and learners in regard to HIV/AIDS education.</p>
57

Perceptions and attitudes of employees toward voluntary HIV/AIDS testing: a South African case study.

Lamohr, Clive January 2006 (has links)
<p>The devastation caused by the Human Immunodeficiency Virus/ Acquired Immune Deficiency Syndrome (HIV/AIDS) is having a major impact on both the social and economic environment in South Africa. HIV/AIDS hits at the core of the businesses structure - the bottom line. In the absence of a cure for the disease or an effective vaccine, the challenge for all the stakeholders is how to successfully contain and limit the impact of the disease. Intervention programmes such as awareness, knowledge sharing and sero-prevailance testing have the potential to limit HIV/AIDS infections and reduce high-risk behaviours. Whilst education and awareness programmes have been relatively successful in highlighting the dangers of HIV infection, perception, attitudes and behaviours of employees towards HIV/AIDS have dampened voluntary HIV screening initiatives. Many South African organisations have commendable HIV/AIDS education and awareness programmes, however, a concerning fact is that employees are reluctant to avail themselves to voluntary HIV/AIDS testing. Stigmatising attitudes toward persons living with HIV/AIDS may reduce people&rsquo / s willingness to have themselves tested for the Human Immunodeficiency Virus (HIV). This may increase the risk of transmission. It may also lead to increased absenteeism in the workplace, and workdays lost resulting from excessive sick.<br /> <br /> The aim of the study was to establish what the perceptions and attitudes are of employees at different levels of the organisation with regard to HIV/AIDS testing. A further aim was to identify possible reasons for the poor employee response to voluntary HIV/AIDS testing. It was thus important for this research to gauge employee knowledge, attitude and behaviour toward HIV/AIDS in order for organisations to develop strategies for effective HIV/AIDS counselling and testing programmes.<br /> <br /> The data for this study was collected by means of a self report questionnaire. The questionnaire was administered to a sample of employees across all levels of the organisation using the convenient sample approach to identify the respondents. Two hundred and forty six (246) out of a total of 600 questionnaires distributed were returned, making the response rate a credible 41%.<br /> The Statistical Package for Social Science (SPSS) was used to analyse the data obtained from the questionnaire. Both inferential and descriptive statistical approaches were used to analyse the data. The Analyses Of Variance (ANOVA) was used to determine whether differences exist in the perceptions and attitudes of employees at different levels and groupings in the organisation. Additionally post hoc tests (i.e. the Scheffe test) were applied to all comparisons of means after the analysis of variance.<br /> <br /> The findings of this research are important for the role of HIV/AIDS testing and awareness/preventions strategies implemented in South Africa. It provides more insight as to why employees resist HIV/AIDS testing. It can furthermore assist organisations in developing strategies for implementing effective HIV/AIDS awareness and/or prevention programmes. More specifically, the findings identified ways in which organisations can redesign their intervention programmes so as to encourage a greater number of employees to submit to voluntary HIV/AIDS testing.</p>
58

The influence of workplace support programmes on the job performance of HIV/AIDS infected employees

Cloete, Michael Stanley 29 February 2004 (has links)
The HIV and AIDS pandemic is arguably the greatest threat facing the world today. The pandemic has a far-reaching impact on society, including the workplace. The effect in the workplace is observed in various areas including a reduction in certain skills levels, mortality and declining job performance of employees living with HIV or AIDS. In addition, the fear of discrimination and stigmatisation prevents infected employees from disclosing their HIV status, thus driving the pandemic underground. Despite the potential negative impact that is looming, many employers still do not have any workplace support programmes in place to manage HIV and AIDS in their organisations. However, some employers have implemented workplace support programmes. This research thus explored the influence of workplace support programmes on the job performance of employees that were living with HIV or AIDS. The findings suggest that job performance is positively influenced where workplace support programmes have been implemented. / Industrial and Organisational Psychology / M.Comm. (Industrial and Organisational Psychology)
59

Att leva med en smittsam blodsjukdom / Living with a contagious blood disease

Asplid, Matilda, Becerra Ponce, Gabriela, Becerra Ponce, Paula January 2018 (has links)
Humant immunbristvirus (HIV), hepatit B och C är blodsmittor som finns världen över. Dessa tre sjukdomar anses som allmänfarliga och som anmälningspliktiga sjukdomar. Livet med en smittsam blodsjukdom kan vara påfrestande för en patient, både fysiskt och psykiskt. Syftet med denna litteraturstudie var att beskriva patienters upplevelse av att leva med en smittsam blodsjukdom. Studien är en allmän litteraturstudie, där kvalitativ forskning användes för att få fram resultatet. Resultatet består av tre teman och sju subteman. De teman som skapades var: rädsla, känslan av att vara osedd och känslan av att vara sedd. Livet med en smittsam blodsjukdom kan vara påfrestande för en patient. Rädslan för sjukdomens konsekvenser är stor. Socialt stöd från anhöriga och sin omgivning har stor påverkan på patientens liv. Brist på socialt stöd kan bidra till att patienten drar sig undan, tar till alternativa hjälpmedel såsom alkohol och narkotika samt till att patienten utvecklar depression. Som vårdpersonal är det viktigt att se patienten bakom den smittsamma blodsjukdomen, då patienter ibland upplever mötet med sjukvården som något negativt. Vårdpersonalen som är rädda för sjukdomen, är även rädda för att bli smittade. Det bidrar till att patienten känner sig dömd och väljer att avstå från behandlingar. / Human immunodeficiency virus (HIV), hepatitis b and c are contagious blood diseases that exists worldwide. These three diseases are considered to be generally dangerous and as a notifiable disease. Living with a contagious blood disease can be stressful to patients both physically and mentally. The purpose of this literature study was to describe patients' experience of living with contagious blood diseases. The study is a general literature study, where qualitative research was used to produce the result. The result consists of three themes and seven different subthemes. That resulted in the creation of three themes: fear, the feeling of being unseen and the feeling of being seen. Living with a contagious blood disease can be stressful to a patient. There is a great fear for the consequence of the disease. Getting social support from relatives and their social environment has a major impact on the patient's life. The lack of social support can make the patient avoid social contact. Patients’ take alternative means such as alcohol, drugs and the patient can develop depression. As a formal caregiver it is important to see the person behind the infection, as the patient experience the meeting with formal caregivers as negative. The formal caregivers are afraid of the disease and to be infected. The patient feels judged and chooses to avoid treatment.
60

Therapeutic and virological outcomes in adults living with HIV / AID at 6 and 12 months after initiation of first-line highly active antiretroviral therapy in an urban population in Namibia

Gorova, Vivianne Inganai January 2010 (has links)
Magister Public Health - MPH / Antiretroviral regimens have side effects that can threaten adherence by patients resulting in evolution of viral resistance due to suboptimal drug levels. Studies have shown that drug adherence of at least 80% can result in viral load suppression. There is no literature on the association between the level of adherence to antiretroviral therapy and the degree of virological suppression in Namibia. The aim of the present study was to determine the therapeutic and virological outcomes in HIV/AIDS patients at 6 and 12 months after initiation of highly-active antiretroviral therapy (HAART) in an urban population in Namibia. The distribution of viral load results showed a low uptake (35%) of virological monitoring at 6 month time point and even lower (12%) at 12 months. A conservative viral load threshold for virological response is required in the Namibian setting. The current adherence level of &gt;80% encourage increased ARV therapy rollout. Poor virological outcome was associated with self-reported adherence. / South Africa

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