Student Number : 9813645X - PhD thesis - Faculty of Health Sciences / Epidemiological information on sexually transmitted infections (STIs) is necessary to assess the magnitude of the burden of infections, to identify vulnerable population groups, to mobilise resources for intervention activities and to monitor the impact of these activities. In addition, specific STI surveillance systems, such as studies on the relative prevalence of aetiological agents of STI syndromes and their antimicrobial susceptibility patterns, are aimed at improving patient care. The studies included in this thesis were designed and implemented to improve our understanding of the epidemiology of STIs and HIV infection in southern Africa. In all the study populations, we observed that high level STI epidemics preceded the explosive spread of HIV infection among high-risk individuals. The studies reported here also demonstrate the importance of triangulating data collected from different recommended STI surveillance components, using a tiered surveillance approach. The studies reported here also explored the bidirectional interactions of HIV and STIs. We observed that different STIs have shown different magnitudes of interaction with HIV infection. We found particularly strong interactions between genital herpes and HIV. At the individual level, HIV-seropositive patients with genital herpes were more frequently found to have atypical clinical presentations, delays in spontaneous healing, longer duration of HSV shedding and increased association with HIV shedding from ulcer and genital exudates. Mixed infections involving chancroid and genital herpes were found to be common, particularly in HIV-seropositive patients. The effectiveness of syndromic treatment targeting only bacterial causes of genital ulceration was significantly reduced due to persistent ulcerations as a result of co-infection with genital herpes. The successful treatment of herpes in men and women was found to be associated with a decline or cessation in HIV shedding into ulcer exudates or genital fluid. The studies have also shown that HIV plasma viral load is the main determinant for HIV shedding in both men and women presenting with STIs. As was the case with HSV infection, there was a strong association between HIV and HPV infection in both men and women. A higher prevalence of HPV infection was found among HIV-seropositive patients in our study population and this may reflect the higher frequency of recurrences and/or longer duration of infection (i.e. persistency). The studies also found that the biological false positive reactions in syphilis serology (i.e. RPR) are not a common occurrence in our HIV-seropositive study population. On the other hand, syphilis serology could be falsely negative in patients with PCR-confirmed primary syphilis who are co-infected with HIV and other aetiological agents causing GUD. In conclusion, the findings of our studies have supported the bidirectional nature of interactions between conventional STIs and HIV infection in southern Africa.

This researched aimed to explore the effects of the Human Immunodeficiency Virus (HIV) upon the visuospatial abilities of HIV-positive adolescents on antiretroviral treatment in South Africa. The literature suggests that the neurology responsible for visuospatial abilities (specifically various white-matter tracts in the brain) is very susceptible to the damaging effect that HIV has on the brain. The research sample consisted of vertically transmitted HIV-positive adolescents, on first line antiretroviral treatment, with a HIV-negative control group comparable on age and SES. The results indicated that there is a significant difference in the visuospatial abilities between adolescents with and without HIV. The expressions of these deficits were displayed differently between males and females, highlighting a differing developmental neurology, and the effect of HIV upon it. The viral strength and health of the immune system were also examined as variables and illuminated interesting results. Overall, the research illustrates the negative effect that HIV has upon developing neurology and the subsequent effects on visuospatial abilities.

Introdução: A adolescência é um dos períodos mais intensos da vida, pelos desafios, descobertas e oportunidades de exploração nela presentes e, por isso, se constitui um determinante da vulnerabilidade ao HIV/AIDS. Objetivo: identificar as evidências científicas da literatura sobre os elementos da vulnerabilidade de adolescentes ao HIV/AIDS. Metodologia: Revisão sistemática da literatura, na modalidade de denominada revisão integrativa. A busca de dados foi realizada nas seguintes bases e bancos de dados: CINAHL, PUBMED, SCOPUS, LILACS, ADOLEC, DEDALUS, Biblioteca Digital de Teses e Dissertações -BDTD, portal de teses da USP, no período de 1996 a 2006. Após avaliação do rigor metodológico dos estudos previamente selecionados, foram incluídos como amostra para análise 41 estudos realizados em diferentes países. Resultados: foram apresentados em duas etapas: a caracterização dos estudos e as evidências científicas dos elementos de vulnerabilidade. Os elementos identificados são iguais ou muito semelhantes nos diferentes países em que foram realizados os estudos, sendo diferente a forma como a vulnerabilidade se expressa, bem como a associação entre os elementos que a compõem. Foram identificados 33 elementos de vulnerabilidade, agrupados segundo três temas centrais: \"comportamentos e conhecimentos sobre o HIV/AIDS\", \"normas sociais\", \"condições socioeconômicas\" e \"gestão de serviços de saúde\". Os elementos da dimensão individual foram identificados com maior freqüência, seguidos pelos da dimensão social e programática. Os elementos da dimensão individual foram: grau e qualidade das informações que o adolescente possui sobre HIV, capacidade de assimilar e incorporar essas informações a sua vida, desconhecimento de sua vulnerabilidade, confiança na monogamia do parceiro, não adoção de práticas de proteção, uso de drogas, recusa ou incômodo em utilizar o preservativo, dificuldade de negociação de adolescentes femininas sobre uso do preservativo, gravidez como maior preocupação da conseqüência do ato sexual desprotegido, relações de gênero, representações da aids (doença do outro). Na dimensão social identificou-se: pobreza, violação dos direitos humanos, relações de gênero (aspectos culturais, exploração sexual, prostituição como meio sobrevivência), esgarçamento de laços familiares, acesso aos meios de escolarização e informação, desemprego, violência e falta de expectativas quanto ao futuro. Os elementos da dimensão programática envolveram: relação entre o usuário adolescente e o profissional (discriminação), qualidade do aconselhamento, teste para HIV, acessibilidade aos serviços de saúde, (descontinuidade das ações preventivas e falta de integração com outros serviços no planejamento e desenvolvimento das ações). Conclusões: a revisão integrativa permitiu identificar evidências científicas dos elementos constantes das três dimensões da vulnerabilidade, descritas no conceito de vulnerabilidade, assim como outros elementos, como a falta de percepção do adolescente sobre sua vulnerabilidade ao HIV/AIDS e a falta de perspectiva quanto ao futuro. A contribuição deste estudo para as práticas de saúde é relevante, uma vez que explicitou por meio das evidências científicas, os elementos da vulnerabilidade do adolescente ao HIV/AIDS, que devem ser considerados no planejamento das ações de prevenção para esse segmento social. Além disso, permitiu identificar lacunas de conhecimento sobre a temática, bem como a qualidade do conhecimento produzido, que também devem ser levados em conta em pesquisas futuras / Introduction: Adolescence is one of the most intense periods of life, because of the challenges, discoveries and chances that are present, and it is also a period of vulnerability infection to HIV. Objective: This study\'s goal is to identify the scientific evidences of literature on the elements of vulnerability of adolescents to the HIV/AIDS. Method: Systematic literature review called integrative review. The search of data was carried through in the following bases and data bases: CINAHL, PubMed, SCOPUS, LILACS, ADOLEC, DEDALUS, Capes- BDTD, portal of thesis of USP, in the period of 1996 to 2006. 661 studies, carried out in different countries, were previously selected to be evaluated for its methodology rigor. After evaluation the methodological rigor of the studies previously selected 41 of those studies were chosen as sample. Results: Where presented in two stages: the characterization of the studies and the scientific evidences of the vulnerability elements. The identified elements were equal or very similar, in the different countries where the studies had been carried through, being different the way that vulnerability was expressed as well as the association between such elements. Thirty- three elements of the vulnerability had been identified and grouped according to the central subject of each element: \"social behaviors and knowledge about HIV/AIDS\", \"social rules\", \" socioeconomical conditions \"and \"management of health services\". The elements of the subjective dimension were identified more frequently, followed by the ones of the social and programmatical dimension. The elements of the individual dimension were: the how much adolescent learns about aids ; the ability to assimilate and incorporate this knowledge to his/her your life; not knowing that he/she is vulnerable; trusting in his partner\'s monogamy; not adopting protection practices; use of drugs, uncomfortable or refusal to use condoms; difficulty in negotiating with her partner on the use of condom; pregnancy as the most undesirable consequence of the unprotected sexual act; gender relations; aids like a disease of other. The following social elements were identified: poverty; human rights violation; gender relations (cultural aspects), sexual exploitation (prostitution as a way of living) weakening of family bonds; access to school and information; unemployment, violence and hopelessness in the future. The following programmatical elements, are pointed out: relation between the adolescent patient and the health professional (discrimination); quality of counseling, testing for HIV, accessibility to health services, lack of preventive actions and lack of integration with other services in planning and development prevention actions for this social segment. Conclusions: This integrative review allowed identifying scientific evidences of vulnerability elements in the three dimensions, described in the vulnerability concept, as well as other elements, like the lack of perception of the adolescent on their own vulnerability to HIV/AIDS infection and the lack of perspective about their future. The contribution of this study for the health practices is relevant, once had proved by means of the scientific evidences, the elements of the vulnerability of the adolescent to the HIV/AIDS, that must be considered in the planning of the actions prevention for this social segment. Moreover, it allowed to identify knowledge gaps on the thematic one, as well as the quality of the produced knowledge, that also must been considered in future research

In the present studies, the essential role of inducer cells for the induction of soluble anti-viral activity against feline immunodeficiency virus (FIV) was investigated. Induction of suppression of FIV replication was found to not strictly require autologous cells and was probably not FIV specific. Suppression was maximum when the inducer cells and the effector CD8+ T cells were in contact with each other, suggesting a potential role for membrane antigen interactions and/or cytokines in the induction process. Additionally, flow cytometry analysis demonstrated a significant increase in the percentage of CD8+ B7-1+ T cells in the peripheral blood of chronically FIV infected cats as compared with uninfected cats. Examination of the FIV V3-V4 envelope sequences from PBMC, lymph nodes and spleen from six cats chronically infected from three to six years with the molecular clone of FIV-PPR did not demonstrate viral variants specific for the tissues examined, emphasizing the critical role of the initial diversity and virulence of the infecting virus inoculum. Additionally, in vitro CD8+ T cell antiviral activity demonstrated by four of the six cats could have led to the control of virus replication in vivo, resulting in the uniform viral variants observed. Infection of specific pathogen free cats with FIV-TX53, an FIV isolate that belongs to an emerging subtype more closely related to FIV clade B, demonstrated an acute stage infection characterized by lymphoadenopathy and a viral dose dependent decline of CD4+/CD8+ T cell ratios below 1 by 11 weeks post infection. Interestingly, an expansion of CD8 low population of CD8+ T cells was observed in the infected cats. The soluble antiviral activity generated from inducer T cell stimulated CD8+ T cells from FIV-A-PPR infected cats also suppressed in vitro replication of the emerging FIV-TX53 and FIV-TX078 isolates. This is the first report demonstrating that the CD8+ T cell antiviral activity is inter-clade effective among FIV strains. As the success of a FIV vaccine could be hampered by occurrence of highly divergent viral variants in the fields, the exploitation of this innate, soluble anti-FIV activity could contribute to the design of novel, safe and complementary anti-FIV therapeutic strategies.

In the present studies, the essential role of inducer cells for the induction of soluble anti-viral activity against feline immunodeficiency virus (FIV) was investigated. Induction of suppression of FIV replication was found to not strictly require autologous cells and was probably not FIV specific. Suppression was maximum when the inducer cells and the effector CD8+ T cells were in contact with each other, suggesting a potential role for membrane antigen interactions and/or cytokines in the induction process. Additionally, flow cytometry analysis demonstrated a significant increase in the percentage of CD8+ B7-1+ T cells in the peripheral blood of chronically FIV infected cats as compared with uninfected cats. Examination of the FIV V3-V4 envelope sequences from PBMC, lymph nodes and spleen from six cats chronically infected from three to six years with the molecular clone of FIV-PPR did not demonstrate viral variants specific for the tissues examined, emphasizing the critical role of the initial diversity and virulence of the infecting virus inoculum. Additionally, in vitro CD8+ T cell antiviral activity demonstrated by four of the six cats could have led to the control of virus replication in vivo, resulting in the uniform viral variants observed. Infection of specific pathogen free cats with FIV-TX53, an FIV isolate that belongs to an emerging subtype more closely related to FIV clade B, demonstrated an acute stage infection characterized by lymphoadenopathy and a viral dose dependent decline of CD4+/CD8+ T cell ratios below 1 by 11 weeks post infection. Interestingly, an expansion of CD8 low population of CD8+ T cells was observed in the infected cats. The soluble antiviral activity generated from inducer T cell stimulated CD8+ T cells from FIV-A-PPR infected cats also suppressed in vitro replication of the emerging FIV-TX53 and FIV-TX078 isolates. This is the first report demonstrating that the CD8+ T cell antiviral activity is inter-clade effective among FIV strains. As the success of a FIV vaccine could be hampered by occurrence of highly divergent viral variants in the fields, the exploitation of this innate, soluble anti-FIV activity could contribute to the design of novel, safe and complementary anti-FIV therapeutic strategies.

Teasing apart the evolutionary forces responsible for biological phenomena is difficult in the absence of a detailed evolutionary history, especially if this history is lacking a temporal component. RNA viruses, due to their rapid rate of molecular and phenotypic evolution, provide a unique biological system in which to study the temporal aspects of evolutionary processes. These types of studies are possible because of relaxed molecular clock dating techniques, which allow the rate of evolution to vary across a phylogenetic tree. The primary focus of the research presented here concerns the age of the simian immunodeficiency virus (SIV), the primate precursor to HIV. SIV has long been thought to be an ancient infection in non-human African primates, and it has been hypothesized that codivergence with its primate hosts has shaped the SIV phylogeny and resulted in a virus capable of apathogenic infection. The codivergence theory was tested by comparing the phylogeny of a group of monkeys thought to be exemplary of SIV-host codivergence to the phylogeny of their SIVs (Appendix A). These phylogenies were incongruent, suggesting that SIV may have infected these monkeys after their common ancestor speciated. The codivergence theory was investigated further by estimating the time of most recent common ancestor for the SIV lineages that directly gave rise to HIV, found in sooty mangabeys and chimpanzees (Appendix B). The temporal estimates suggest that these SIV lineages are only of hundreds of years old, much younger than expected under the codivergence hypothesis. Next, the same dating techniques were employed to elucidate the evolutionary history of an emerging RNA virus of shrimp, Taura syndrome virus (Appendix C). This analysis provided phylogenetic confirmation that Taura syndrome virus emerged out of the Americas and spread rapidly around the world. Finally, because all of these studies utilized relaxed molecular clocks, a simulation study was performed to test the hypothesis that relaxed molecular clocks provide higher quality phylogenetic inference compared with traditional time-free phylogenetic inference (Appendix D). This simulation found no difference in the overall quality of phylogenetic inference between these methods.

Thesis--Auburn University, 2008. / Abstract. Vita. Includes bibliographical references (p. 60-90).

Thesis (Ph. D.)--University of Washington, 2007. / Vita. Includes bibliographical references (leaves 99-126).

Orientador: João Pessoa Araújo Júnior / Banca: Lenice do Rosário de Souza / Banca: Alexandre Secorum Borges / Resumo: O Vírus da Imunodeficiência Felina (FIV) é um lentivírus que causa uma síndrome de imunodeficiência em gatos domésticos. O FIV tem sido particularmente utilizado em estudos de resistência viral aos análogos de nucleosídeos devido a Transcriptase Reversa (TR) apresentar propriedades físicas, catalíticas e sensibilidade às drogas semelhantes à TR do HIV. Os objetivos desse trabalho foram tratar com AZT gatos naturalmente infectados com o FIV, fazer o monitoramento da carga viral e DNA proviral por PCR em tempo real e monitoramento genético por seqüenciamento. Dos 12 animais infectados, 6 receberam o AZT na dose de 10mg/kg/dia e 6 receberam placebo. Durante 96 dias de tratamento, o plasma e sangue destes animais foram analisado com relação à carga viral e concentração relativa de DNA proviral utilizando-se a técnica de quantificação relativa por PCR em tempo real com SYBR Green, desenvolvida por nossa equipe. Além disso, foi realizado o sequenciamento genético da região que codifica a TR de 3 dos animais. Foi realizada com sucesso a padronização da PCR em tempo real para quantificação relativa do FIV. Não houve diferença estatisticamente significativa da carga viral ou do DNA proviral entre os grupos tratado e controle. O seqüenciamento genético revelou a presença de lisina na posição 41 do sítio ativo da TR. A presença deste aminoácido confere até 4 vezes menor sensibilidade ao AZT em mutantes do HIV. Por possuir alta estabilidade genética, supomos que os vírus dos demais animais não sequenciados possuem também a 41-lisina A presença da 41-lisina pode ser uma das possíveis explicações para a falha do tratamento com AZT. Outra hipótese é a de que a dose fornecida não foi adequada. / Abstract: Feline Immunodeficiency Virus (FIV) is a lentivirus which causes a progressive disruption of the host's immune functions. FIV has been particularly used as a model for studies in retroviral resistance to nucleoside analogs because its similarities in physical properties, catalytic and sensitivity in comparison with HIV/RT. The aims of this work were to treat cats naturally infected with FIV, quantify viral load and proviral DNA by real time quantitative PCR with SYBR Green and analyze the viral nucleotide sequence. From 12 animals naturally infected, 6 received AZT at a dose of 10mg/kg/day and 6 received placebo. During 96 days of treatment, viral load and concentration of proviral DNA were measured by relative quantitative real time PCR developed by our staff. The nucleotide sequence of the RT encoding region was also achieved for 3 animals. The real time PCR relative quantification was successfully standardized for FIV. There was no significant statistical difference between treated and control groups. The nucleotide sequence revealed a lysine at position 41 on the enzyme active site. This lysine confers 4-fold decreased sensitivity to AZT in HIV RT-mutants. FIV subtype B has high genetic stability and we purposed that the other virus not sequenced have the same amino acid and hypothesized that this mutations can be one of the reasons determining the failure of the treatment. The other hypothesis is that the dose was not adequate. / Mestre

Philosophiae Doctor - PhD / Tuberculosis (TB) is an infectious disease with adverse effect on a global scale. The disease is one of the major causes of death in sub-Saharan Africa. Nearly 70% of TB-infected persons are co-infected by the human immunodeficiency virus (HIV). About 50% of TB/HIV patients are smear negative and up to 28% are sputum scarce, which is a significant problem in South Africa since sputum smear microscopy is the most widely used diagnostic test for TB. The detection of Mycobacterium tuberculosis (MTB) and resistance to the TB drug rifampicin (RIF) are the basis of the GeneXpert MTB/RIF protocol. The GeneXpert MTB/RIF is an automated nucleic acid amplification technique for detecting the DNA that originates from MTB. However, low sensitivity and low concentrations of MTB for DNA amplification are a serious issue associated with the protocol. Therefore, other TB diagnostic methods, such as the ones involving biochemical markers of TB, are becoming very important. / 2020-08-31