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.

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.

<p>Eligibility for antiretroviral therapy (ART) in HIV-infected patients is defined either by a cluster of differentiation antigen 4 (CD4) count of less than 200cells/mm3 or clinical diagnosis of WHO stage III and IV. Therefore, the decision to start ART becomes difficult when CD4 cell count is not available. With limited laboratory infrastructure, the decision to start ART is usually made based on clinical symptoms leading to late commencement of ART. This calls for alternative criteria to see if nail discoloration (ND) correlates with low CD4 count among untreated HIV infected patients. This will serve as a complementary screening tool for identifying asymptomatic ARV naive HIV patients with a CD4 cell count of less than 200cells/mm3 which signifies&nbsp / severe immunosuppression. Study Design and Setting: This was a quantitative cross-sectional descriptive and analytical study involving adult ART na&iuml / ve HIV infected patients in WHO stage I and II. Systematic sampling was used to select the participants from all adult ART na&iuml / ve HIV infected patients attending APIN clinic, located at the Jos University Teaching Hospital (JUTH), Jos, Nigeria. Data Collection: Face-to-face interviews, physical examination and relevant laboratory investigations with selected participants were conducted using a questionnaire guide. Questions on socio-demographic characteristics, clinical data, general physical examinations including finger nail examination and photographing with subsequent laboratory investigations including CD4 count and western blot were employed. Data Analysis: Variables were categorized and data analyzed using descriptive statistics including the frequency, percentage frequency / mean and standard deviation of continuous variables. Association between CD4 count of &le / 200cells/mm3 and ND was tested using the chisquare test with an alpha level of 0.05. Prevalence of ND, sensitivity, specificity, positive predictive and negative predictive values and accuracy of the screening test of ND was calculated. Results: 394 patients had their fingernails photographed and assessed. It was shown that distal banded and grey nails were the common types of ND seen with a prevalence of 38%. There was an association between CD4 count &le / 200cells/mm3 and ND (p&lt / 0.0001). CD4 count &le / 200cells/mm3 was a risk factor for developing ND (RR=2.3[1.8-3.6]). The association has a sensitivity of 78%, specificity of 55%, positive predictive value of 50%, and negative predictive value of 80% and accuracy of test 63%. Conclusion: With a significant association (p&lt / 0.0001) and a sensitivity of 78%, ND can be a useful clinical indicator of immune dysfunction mediated by HIV among patients in WHO stage I or II. ND can either be a clinical sign or a symptom in HIV patients with a CD4 of &le / 200cells/mm3 as seen in the study as the specificity and sensitivity of ND compared favourably with other WHO stage III diagnosis. Recommendations: Nail discoloration should complement CD4 count as an additional staging sign to help identify patients likely to benefit from ART especially in resource-limited settings. Finally, all patients with grey or distal banded should be on co-trimoxaxole prophylaxis in line with WHO /national guideline on the use of co-trimoxaxole for all HIV positive patients with a CD4 cell count of &le / 350cells/mm3.</p>

<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>

Thèse numérisée par la Division de la gestion de documents et des archives de l'Université de Montréal

<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>

La découverte d’adjuvants de vaccination est en pleine expansion dans un contexte règlementaire de plus en plus strict. L’objectif de ce travail de thèse a été de proposer un adjuvant hautement caractérisé de la famille de la lysophosphatidylcholine (LPC) pour un développement clinique. Il avait été précédemment montré que la LPC d’oeuf de poule présentait des propriétés adjuvantes in vitro et in Vivo. Cependant, il s’agit d’un mélange hétérogène d’espèces moléculaires de LPC peu exploitable en clinique. Nous avons donc cherché à 1/ cribler in vitro 5 différentes espèces moléculaires de LPC ayant des activités adjuvantes, et 2/ évaluer chez la souris l’aptitude des molécules sélectionnées à induire des réponses humorales et cellulaires.Deux candidats, les LPC C16 :0 et C18 :0, induisent in vitro la maturation de cellules dendritiques humaines caractérisée par l’augmentation de l’expression des marqueurs de surface, la production de chimiokines pro-Th1 et l’engagement vers un profil Th1 de lymphocytes T CD4+. Chez la souris, l’injection i. v. des candidats induit une réponse inflammatoire transitoire et modérée au profil Th2 (IL-5, IL-6). De plus, ces espèces induisen une réponse humorale spécifique contre 3 antigènes viraux après injection s. c. ou i. m. (NS3du VHC, HBsAg du VHB et gp120 du VIH), proche de celle obtenue avec l’alun et à des doses faibles supposées non toxiques. Dans ces modèles, en revanche, les LPC individuelles ne semblent pas induire de réponses cellulaires spécifiques.L’ensemble de ces résultats ouvre d’intéressantes perspectives pour l’utilisation des LPC C16 :0 et C18 :0 en tant qu’adjuvants de vaccination de réponses immunitaires humorales. / The evaluation of new vaccine adjuvants is growing fast in a stringent regulatory environment. The aim of this thesis project was to propose a highly defined adjuvant derived from the lysophosphatidylcholine (LPC) for clinical development. It has been previously shown that an egg-derived LPC has in vitro and in Vivo adjuvant features. However, it is composed of a heterogeneous mixture of molecular species of LPC, thus precluding itsclinical evaluation. Therefore, we decided to 1/ screen in vitro 5 single species of LPC fortheir adjuvant properties, and 2/ evaluate in the mouse model the ability of selected compounds to induce humoral and cellular responses.Two candidates, the C16:0- and C18:0-LPC, induce in vitro maturation of human dendritic cells as defined by an up regulation of the expression of surface markers, production of pro-Th1 chemokines, and engagement of CD4+ T lymphocytes towards a Th1 profile. Inmice, i. v. injection of both candidates triggers a transient and moderate inflammatory response with a Th2 profile (IL-5, IL-6). In addition, these species initiate specific humoral responses against 3 viral antigens following s. c. or i. m. injection (NS3 from HCV, HBsAgfrom HBV and gp120 from HIV), close to what is achieved with alum and at low doses expected to be safe in humans. In these models, however, single LPC do not mediatespecific cellular responses. Over all, these results open interesting perspectives for the single

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)

Made available in DSpace on 2016-12-23T13:56:09Z (GMT). No. of bitstreams: 1 Dissertacao de Alana Rocha Puppim Fraga.pdf: 1890576 bytes, checksum: 21b76a7e172deaf402981920bb4b542d (MD5) Previous issue date: 2011-08-22 / The thyroid follicular cells have a close interaction with the immune system and are often injured by several factors determining autoimmune inflammatory response. Immunosuppression caused by Human Immunodeficiency Virus (HIV) infection provides changes in diverse organic systems, including the endocrine system. To assess the consequences of immunosuppression on the thyroid inflammation response, were examined 63 autopsy thyroid glands from patients infected with HIV, of whom 46 were matched by age and gender with patients without HIV infection. In addition to the medical records, representative thyroid gland fragments were analyzed under optic microscope. Also immunohistochemistry for identification of antigens p24, CD4, CD8 and CD20 were performed. Volume measures and glandular ecogenicity were taken correlating with microscopic findings in order to detect pathologic processes. There was no statistical difference in ecogenicity and volume measurements between the groups. The antigen p24 was not identified in any glands. Sixty seven per cent of thyroids sampled, either HIV group or control group, showed inflammatory infiltrate. There was a significant decrease in CD4+ cells in inflammatory infiltrate of HIV group. Microorganisms in thyroid tissue were observed in 19,04% of HIV group and and 3% of control group. CD8+ intraepithelial and interfollicular cells were identified in all glands. CD20+ cells were identified with no significant difference between groups. The inflammatory response may be related, in both groups, of the occurrence of sepsis and thyrotoxic drugs. The reduction of CD4+ cells contributes to changes in the thyroid inflammatory response. The CD8+ intraepithelial cells detected in all glands with little predominance in HIV group may indicate changes in CD4+/CD8+ cells as observed in other organic systems. The measurement of thyroid volume and ecogenicity were not able to identify the specific occurrence of pathological processes between the groups / A célula folicular tireoidiana apresenta estreita interação com o sistema imune e é frequentemente agredida por diversos fatores que determinam resposta inflamatória crônica, geralmente do tipo autoimune. A imunodepressão provocada pela infecção pelo Vírus da Imunodeficiência Humana (HIV) determina alterações em diversos sistemas orgânicos, incluindo o endócrino. Para avaliar as consequências dessa imunodepressão sobre a reação inflamatória tireoidiana, foram estudadas 63 tireóides provenientes de autópsia de indivíduos infectados pelo HIV, dos quais 46 foram pareadas por idade e sexo com controles sem infecção pelo HIV. Além de dados de prontuário, fragmentos representativos da glândula tireoide foram analisados ao microscópio óptico associando-se a imuno-histoquímica para a identificação de antígeno viral p24, células CD4, CD8 e CD20. Foram aferidas medidas de volume e ecogenicidade glandular buscando correlacionar a estes achados as alterações histológicas. Não foi encontrada diferença estatística nas medidas de volume e ecogenicidade entre os grupos. Não se identificou marcação para o antígeno p24 em nenhuma das glândulas estudadas. Sessenta e sete por cento das tireóides, tanto do grupo HIV como do grupo controle, apresentaram infiltrado inflamatório com diminuição significativa de células CD4+ no grupo HIV. Observou-se a presença de microrganismos na tireoide do grupo HIV em 19% das amostras e em 3% do grupo controle. Células CD8+ intraepiteliais e interfoliculares foram identificadas em todas as glândulas estudadas. Células CD20+ foram identificadas sem diferença significativa entre os grupos. A detecção de inflamação pode estar relacionada, nos dois grupos estudados, à ocorrência de sepse e uso de drogas tireotóxicas. Concluímos que no grupo HIV a diminuição de células CD4+ no infiltrado inflamatório contribui para modificações da resposta inflamatória tireoidiana. A presença de células CD8+ intraepiteliais em todas as glândulas estudadas com discreto aumento no grupo HIV sugere que a migração destas células pode estar relacionada com alteração na relação das células CD4+/CD8+ semelhante ao que já se observa em outros sistemas orgânicos. A aferição do volume e ecogenicidade tireoidianas não foram capazes de identificar a ocorrência específica dos diferentes processos patológicos entre os grupos estudados

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.