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Carlson, Jolene Christine. "Dynamics of protection against virulent challenge in swine vaccinated with attenuated African swine fever viruses." Diss., Kansas State University, 2016. http://hdl.handle.net/2097/34143.
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Doctor of PhilosophyDepartment of Diagnostic Medicine/Pathobiology
Manuel Borca
Stephen Higgs
African swine fever (ASF) is a lethal hemorrhagic disease of swine caused by a double-stranded DNA virus. ASFV is endemic in Sardinia and Saharan Africa and has been recently expanded from the Caucasus to Eastern Europe. There is no vaccine to prevent the disease and current control measures are limited to culling and restricted animal movement. Swine infected with attenuated strains are protected against challenge with a homologous virulent virus, but there is limited knowledge of the host immune mechanisms generating that protection. Swine infected with Pret4 virus develop a fatal severe disease, while a derivative strain lacking virulence-associated gene 9GL (Pret4Δ9GL virus) is completely attenuated. Swine infected with Pret4 Δ9GL virus and challenged with the virulent parental virus at 7, 10, 14, 21, and 28 dpi showed a progressive acquisition of protection (from 40% at 7 dpi to 80% at 21 and 28 dpi). This animal model was used to associate the presence of host immune response and protection against the challenge. Anti-ASFV antibodies and cytokines in serum, as well as ASFV-specific IFN-γ production in PBMCs, were assessed in each group. Interestingly, with the exception of ASFV-specific antibodies in the surviving swine challenged at 21 and 28 dpi, no solid association between any of the parameters assessed and the extent of protection could be established. These results were corroborated using a similar model based on the use of a rationally attenuated derivative of the highly virulent strain Georgia 2007. These results, encompassing data from 114 immunized swine, underscore the complexity of the system under study where it is very plausible that protection against disease or infection relies heavily on the concurrence and or interaction of different host immune mechanisms.
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Heskett, Eric A. "Efficacy of a recombinant Herpes Virus of Turkeys vector vaccine, expressing genes to Newcastle disease virus and Marek's disease virus in chickens and turkeys, against exotic Newcastle disease virus challenge." [Gainesville, Fla.] : University of Florida, 2003. http://purl.fcla.edu/fcla/etd/UFE0000700.
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Keckler, M. Shannon. "The role of cytotoxic T lymphocytes in protection from pathogenic simian immunodeficiency virus challenge : a dissertation /." San Antonio : UTHSC, 2007. http://proquest.umi.com/pqdweb?did=1414133541&sid=1&Fmt=2&clientId=70986&RQT=309&VName=PQD.
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Souto, Ricardo Gomes. "Evaluation of cross protection by an attenuated African swine fever virus isolate against heterologous challenge." Diss., University of Pretoria, 2012. http://hdl.handle.net/2263/33369.
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African Swine Fever Virus (ASFV) is an Asfivirus and is the only member of the family Asfarviridae. It manifests as a disease that varies from acute to sub-acute or chronic forms. A true carrier state in domestic pigs is unknown but chronically affected individuals may carry and spread the virus for extended periods. African Swine Fever (ASF) is a socio-economically important disease characterized by high morbidity and mortality affecting the livelihood of many small to big scale farmers and seriously compromising international trade. Strategic measures to control this disease are by physical containment and culling in outbreak situations. There is no vaccine available. Nevertheless, every pork producer should ideally be actively involved in having biosecurity measures in place to avoid contamination and contacting their veterinary services in case of suspicion of ASF to have appropriate samples analysed. Official veterinary services must be equipped with proper diagnostic tools in order to provide a quick response. The sensitivity of currently available diagnostic tests at the Transboundary Animal Diseases Programme, Onderstepoort Veterinary Institute was analysed in order to report the best technique available. Sensitivity to ASF virus infection and therefore diagnostic potential of cell primary cultures as bone marrow macrophages, blood macrophages and alveolar macrophages was done via comparison of titre results from inoculations of ASFV SPEC 257 as control, and ASFV MOZ 1/98. In addition, molecular detection of specific DNA fragments within the viral genome were compared using five different PCRs. Bone marrow macrophage cultures and blood macrophage cultures were the most reliable cells whereas alveolar macrophages more often showed contamination. Results show that PPA PCR and real time PCR detected the highest diluted samples, thus the lowest concentration of virus, in both trials done with ASFV MOZ 1/98 and ASFV SPEC 257.
In addition, animal trials were performed by inoculating domestic pigs with four different ASFV isolates of varying pathogenicity. These viruses were all from distinct geographic origins. Non-virulent ASFV OURT 3/88 and high virulent ASFV BENIN 1/97 were previously described and used as reference viruses. ASFV MOZ 1/98, suspected of having high virulence and ASFV MKUZE, which was thought to be of low virulence were included in this study to provide further information on the pathological and clinical outcome of the disease as well as measuring viral replication in various organs and blood. The study showed that ASFV MKUZE was of intermediate virulence, whilst ASFV MOZ 1/98 was highly virulent with a high mortality rate. Results confirmed the inadequacy of ASFV MKUZE to act as vaccine opposed to ASFV OURT 3/88.
Following this, a potential vaccine by use of attenuated Portuguese ASFV OURT 3/88 tested against virulent heterologous challenge with a strain now known with certainty to cause acute ASF, the isolate ASFV MOZ 1/98 collected from a diseased pig in Mozambique. Domestic commercial pigs where submitted to either one or two vaccinations before challenge. Viral load in blood and tissue samples was higher in unvaccinated animals and higher in single vaccinated than in pigs vaccinated twice. However, acute ASF afflicted all groups with severe clinical signs and post-mortem lesions. Although it did not confer total immunity it was determined that pigs vaccinated with European attenuated ASFV OURT 3/88 acquired partial protection against challenge with virulent southern Africa ASFV MOZ 1/98.Dissertation (MSc)--University of Pretoria, 2012.
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Veterinary Tropical Diseases
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Laforce, Wendy Marie. "The effect of vaccinia virus challenge and adjuvant induced arthritis on chemokine receptor expression by rat leukocytes." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0016/MQ57202.pdf.
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Regnard, Guy Louis. "Development of a potential challenge model and plant-produced vaccine candidate for beak and feather disease virus." Doctoral thesis, University of Cape Town, 2015. http://hdl.handle.net/11427/15690.
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Psittacine beak and feather disease (PBFD), the most prevalent viral disease affecting psittacines, is caused by beak and feather disease virus (BFDV). An outbreak of the disease has been reported in wild endangered Cape parrots (Poicephalus robustus), which is endemic to South Africa. No treatment or vaccine is commercially available. In this study, an investigation into the outbreak was undertaken. BFDV diversity was assessed and viral load and clinical signs correlated. A plant-produced BFDV subunit vaccine was produced in parallel with a corresponding challenge model. Cape parrots were assessed and 53 blood samples collected. Viral load was determined using quantitative real-time PCR (qPCR), and 22 BFDV full-length genome sequences acquired to infer phylogenetic relatedness. The capsid gene (cp) was optimised for transient Agrobacterium-mediated expression in whole-plant Nicotiana benthamiana (N. benthamiana). Virus-like particles (VLPs) were purified and analysed using transmission electron microscopy. Virions from a Palm cockatoo (Probosciger aterrimus) were purified and a BFDV dsDNA molecular clone was synthesised and replication assessed in 293TT mammalian cells and N. benthamiana using rolling circle replication and qPCR. Two distinct BFDV phylogenetic clusters were reported for Cape parrots, and a direct correlation was seen between viral load in the blood and clinical signs in PBFD-afflicted birds. The CP was successfully expressed in N. benthamiana, and increased through optimisation of Agrobacterium infiltration density and the inclusion of the NSs silencing suppressor. The CP formed VLPs, which were shown to be morphologically similar to infectious virions. The dsDNA molecular clone was shown to replicate autonomously in mammalian 293TT cells, and in plants with the assistance of the Bean yellow dwarf virus replication associated protein (Rep). BFDV genetic diversity in Cape parrots highlights the importance of ensuring new strains are not inadvertently introduced into the wild. This is the first systematic investigation of virus diversity in Cape parrots and assessment of BFDV viral load in a wild psittacine population. The CP was successfully produced in planta and presence of VLPs suggests the possibility of developing pseudovirions. This is the first reported replication of BFDV in tissue culture, and will greatly expand the scope of available research.
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Niederwerder, Megan C. "Clinical disease and host response of nursery pigs following challenge with emerging and re-emerging swine viruses." Diss., Kansas State University, 2015. http://hdl.handle.net/2097/20491.
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Doctor of PhilosophyDiagnostic Medicine/Pathobiology
Raymond R. R. Rowland
Emerging viral diseases cause significant and widespread economic losses to U.S. swine production. Over the last 25 years, porcine reproductive and respiratory syndrome virus (PRRSV), porcine circovirus type 2 (PCV2) and porcine epidemic diarrhea virus (PEDV) have emerged or re-emerged, costing the industry billions through increased mortality and clinical or subclinical reductions in growth. Nursery pigs are greatly affected by these viruses due to high susceptibility to primary and secondary infections after weaning. However, clinical disease occurs in only a subpopulation of infected pigs and can vary drastically from sudden death to poor growth performance. This thesis documents a series of 4 studies where nursery pigs were challenged with either PRRSV/PCV2 or PEDV; the associations between clinical outcome and several factors affecting viral pathogenesis were investigated. In the first study, the administration of PRRS modified live virus vaccine prior to co-challenge with PRRSV/PCV2 was shown to protect against PRRS but enhance PCV2 replication and pathogenesis. This study provides insight into the role that PRRS vaccination has in both the control and potentiation of clinical disease. In the second study, microbial populations were compared between pigs with the best and worst clinical outcome following PRRSV/PCV2 co-infection. Increased fecal microbiome diversity was associated with improved clinical outcome; however, worst clinical outcome pigs had prolonged and greater virus replication, highlighting the host response to viral challenge as a primary determinant of clinical outcome. In the third study, 13 clinical phenotypes were compiled for >450 pigs after PRRSV/PCV2 co-infection. Duration of dyspnea and the presence of muscle wasting had the strongest associations with reduced weight gain. This study highlights the opportunity to improve animal welfare and production through improvements in clinical health. In the fourth study, clinical disease was mild to moderate and occurred within the first week after pigs were challenged with PEDV. However, PEDV was detected weeks after clinical disease had resolved and may implicate nursery pigs as an important source of viral carriage and transmission. Overall, the goal of this thesis was to develop models for understanding the impact of emerging and re-emerging viruses to improve recognition and control of disease.
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Ashok, M. S. "Evaluation Of The Efficacy Of DNA Vaccines For Japanese Encephalitis In A Murine Intracerebral Japanese Encephalitis Virus Challenge Model." Thesis, Indian Institute of Science, 2000. http://hdl.handle.net/2005/169.
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Japanese encephalitis virus (JEV), a member of the family flaviviridae, is one of the most important pathogens of the developing countries, causing high mortality and morbidity amongst children. The present study is aimed at the development of a DNA vaccine for Japanese Encephalitis (JE). As a first step towards developing a DNA vaccine for JE, an eukaryotic expression plasmid encoding the envelope (E) glycoprotein of Japanese Encephalitis Virus (pCMXENV) was constructed. This plasmid expresses the E protein intracellularly, when transfected into Vero cells in culture. Several independent immunization and intracerebral (i.e.) JEV challenge experiments were carried out and the results indicate that 51% and 59% of the mice are protected from lethal i.e. JEV challenge, when immunized with pCMXENV via intramuscular (i.m.) and intranasal (i.n.) routes respectively. JEV-specific antibodies were not detected in pCMXENV-immunized mice either before or after challenge. JEV-specific T cells were observed in mice immunized with pCMXENV, which increased significantly after JEV challenge indicating the presence of vaccination-induced memory T cells. Enhanced production of interferon-y (EFN-y) and complete absence of interleukin-4 (IL-4) in splenocytes of pCMXENV-immunized mice on restimulation with JEV antigens in vitro indicated that the protection is likely to be mediated by T helper (Th) lymphocytes of the Thl sub type. These results demonstrated that immunization with a plasmid DNA expressing intracellular form of JEV E protein confers significant protection against i.e. JEV challenge even in the absence of detectable antiviral antibodies. We then examined the potency of JEV DNA vaccines as well as that of the inactivated mouse brain derived BIKEN vaccine in the i.e. challenge model. The results indicate that all the mice immunized with BIKEN JE vaccine were protected against i.e. JEV challenge while 50% protection was observed in case of mice immunized with pJME or pJNSl and 38% protection was observed in pCMXENV-immunized mice. Immunization with both pJME and pJNSl resulted in 66% protection. These results indicate that the BIKEN JE vaccine confers better protection against i.e. JEV challenge than DNA vaccines. The fact that the BIKEN vaccine conferred better protection against i.e. JEV challenge than DNA vaccines indicated that the i.e. JEV challenge model can be exploited further to examine the potency of different DNA vaccine constructs. Towards this goal, we constructed plasmids that encode secretory or nonsecretory forms of JEV E protein and examined their potency in the i.e. JEV challenge model. Our results indicate that i.m. immunization of mice with plasmid encoding secretory form of JEV E protein confers higher level (75%-80%) protection than those encoding nonsecretory forms. Cytokine analysis of splenocytes isolated from DNA immunized mice after stimulation in vitro with JEV revealed that immunization with plasmid encoding secretory form of JEV E protein induces both Thl and Th2 responses while those encoding nonsecretory forms induce only Thl type of response. Thus, synthesis of secretory form of JEV E protein results in an altered immune response leading better protection against i.e. JEV challenge. Based on our studies, we propose that both cellular and humoral immune responses play a key role in protective immunity against i.e. JEV challenge and DNA vaccines that can induce higher levels of neutralizing antibodies will be as efficient as the BIKEN vaccine in conferring protection against i.e. JEV challenge.
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Osuagwuh, Uchebuchi I. "Semen quality and the excretion of lumpy skin disease virus in semen following vaccination and experimental challenge of vaccinated bulls." Diss., University of Pretoria, 2006. http://hdl.handle.net/2263/23607.
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The aim of this study was to determine the efficacy of vaccination in preventing LSDV excretion in semen and negative effects on semen quality. Lumpy skin disease (LSD) is caused by a virus in the genus Capripoxvirus of the family Poxviridae. The virus has been reported to be excreted in the semen of experimental infected nonvaccinated bulls. Nevertheless, vaccination has been the most widely used method to reduce and prevent the spread of the disease. This work was done to determine the efficacy of lumpy skin disease vaccination in preventing the excretion of lumpy skin disease virus (LSDV) in semen of experimentally infected vaccinated bulls. It also determined further the effect of vaccination and experimental infection on semen quality. Six serologically negative bulls 11-16 months of age were vaccinated with an attenuated Neethling strain of LSD vaccine, and a repeated dose of vaccine was given twenty one days later. These bulls were then experimentally infected by intravenous injection with a virulent field strain of LSDV (V248/93). Six unvaccinated bulls were similarly infected to act as controls. All animals were observed for clinical signs, blood and semen was collected and evaluated twice a week until day 40 post vaccination and every two days until day 28 post-infection when the trial was terminated. Serology was done using the serum neutralization test and viraemia was determined by virus isolation. Semen was examined by polymerase chain reaction (PCR) for the presence of virus. Semen evaluation was done visually and microscopically. Two of the unvaccinated controls developed severe LSD, two showed mild symptoms and two were asymptomatic. No clinical abnormalities were detected following vaccination, and clinical signs were limited to mild lymph node enlargement in four bulls following challenge of the vaccinated bulls. There was a significant difference (P<0.05) in semen quality after experimental infection of the unvaccinated bulls. In the vaccinated bulls, semen quality showed no significant difference (P>0.05) following vaccination and challenge. Three of the vaccinated bulls were serologically positive at the time of experimental infection and four at the end of the trial. Five unvaccinated bulls were found to be viraemic during the course of the trial. No vaccinated bulls were found to be viraemic at any stage. Four unvaccinated bulls excreted the virus in their semen during the course of the trial. Viral nucleic acid was not detected in any semen samples following vaccination or challenge in vaccinated bulls. This study provides evidence that vaccination against LSD prevented the excretion of viral particles in semen. It also illustrated that LSD vaccination prevented any effect on semen quality after experimental infection with virulent virus.Dissertation (MSc (Production Animal Studies))--University of Pretoria, 2006.
Production Animal Studies
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Soko, Misheck Mica Mafeni. "Evaluation of transgenic RNAi banana and plantain lines for resistance to banana bunchy top disease." Thesis, Queensland University of Technology, 2022. https://eprints.qut.edu.au/228515/1/Misheck%20Mica%20Mafeni_Soko_Thesis.pdf.
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This project evaluated genetically modified Cavendish bananas and plantains for field and glasshouse resistance to banana bunchy top virus in Malawi in Africa, over a three-and-a-half-year period. The study identified several GM lines with significant resistance to the virus and provided a rare insight into virus-vector relations and the climate. The research showed that rigorous field assessment of GM plants for disease resistance is critical and that immunity to this virus will likely only be achieved using a multi-faceted resistance strategy.
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Bwala, Dauda Garba. "Challenge studies in chickens to evaluate the efficacy of commercial Newcastle disease vaccines against the strains of Newcastle disease virus prevalent in South Africa since 2002." Diss., University of Pretoria, 2009. http://hdl.handle.net/2263/22859.
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Since 2002, the South African poultry industry has experienced outbreaks of Newcastle disease (ND) caused by a newly introduced virus (NDV) strain belonging to lineage 5d/VIId (“goose paramyxovirus” - GPMV). Control of the disease has proved difficult with commercially available vaccines appearing ineffective. In the first of two studies, broilers chicks were vaccinated with VG-GA vaccine (lineage II), then challenged with both GPMV and a “classic” challenge virus (RCV) of lineage 3d/VIII to compare the efficacy of the vaccine against both strains. In the second study, commercial and SPF hens in lay were vaccinated with La Sota vaccine and challenged with GPMV isolate, and immunohistochemistry staining used to determine the distribution pattern of viral antigen in the oviduct of the hens. The second study also compared the efficacy of cloacal and ocular routes of vaccination. The first study did not detect any statistically significant difference in protection offered by the vaccine against the GPMV strain in comparison to the RCV strain. The protection offered by the vaccine against challenge with both viruses was found to be dosedependant with 106.0 EID50 producing a 100% protection and 94.44% and 13.89% for 104.5 EID50 and 103.0 EID50 vaccination doses respectively. Protected birds did not manifest clinical signs, but still had macropathological lesions in some organs at necropsy. The computed protective doses (PD50 and PD90) for the VG-GA vaccine were 103.51 and 104.38 for GPMV and 103.79 and 104.43 for RCV. Results from the second study showed no clear difference in the protection of the oviduct from challenge with GPMV by either the cloacal and ocular routes of vaccination. Vaccinated birds were fully protected (100%) against challenge by La Sota vaccine, but not against infection and replication of the virus, as birds showed varying degrees of macropathology with numerous stained viral antigens in the oviducts demonstrated by immunohistochemistry. The susceptibility and colonisation of the oviduct of laying hens by both the lentogenic La Sota and the virulent NDV isolates was confirmed, with the uterus being more susceptible than magnum and isthmus. Necrosis and apoptosis of cells of the oviduct were not detected but cellular infiltration, gland dilatation and interstitial oedema were observed.Dissertation (MSc (Veterinary Science))--University of Pretoria, 2009.
Production Animal Studies
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Garcia, Andrea Isabel Estévez. "Perfil patogênico de um isolado do vírus da raiva procedente do morcego insetívoro Lassiurus ega e do virus fixo Challenge Virus Standard (CVS) no modelo hamster (Mesocricetus auratus) e camundongo (Mus musculus)." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/10/10134/tde-18082010-173232/.
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O isolamento do vírus da raiva (genótipo 1) a partir de morcegos não hematófagos está se tornando cada vez mais freqüente nas grandes cidades do Brasil. Este trabalho foi delineado para investigar a patogenicidade de um isolado do vírus da raiva, do morcego insetívoro Lassiurus ega, procedente do município de Presidente Prudente SP, em comparação ao vírus fixo da raiva, amostra CVS/32 (Challenge Vírus Standard). Os vírus foram reativados por meio de inoculação intracerebral em camundongos e os experimentos de patogenicidade foram realizados em camundongos e hamsters, desafiando-os pelas vias intramuscular (IM), intradérmica (ID), intranasal (IN) e abrasão superficial da pele (AP). A presença do vírus nos cérebros de animais que haviam manifestado sinais compatíveis à raiva, foi confirmada mediante a prova de imunofluorescência direta. Foram considerados para a avaliação da patogenicidade o quadro clínico, proporção de mortos, e a duração dos períodos de incubação (PI) e clínicos (PC) em dias. Em hamsters, o isolado de L. ega exibiu um quadro furioso, com proporção total de mortos de 2.60%; assim discriminada: 2.08% IM (PI: 11 dias; PC: 6 dias) e 8.33% IN (PI:10.66 ± 1.15 e PC: 7.33 ± 1.54). A presença do vírus no SNC foi detectada apenas em animais inoculados por essas vias. Por outro lado, o vírus CVS produziu um quadro paralítico com mortalidade total de 39.84%, com a seguinte distribuição: 62.50% IM (PI 7.50 ± 2.33; PC: 5.13 ± 1.89) 78.12% ID (PI 9.13 ± 2.23; PC 3.88 ± 2.23) 18.75% IN (PI 12.00 ± 2.77; PC 7.14 ± 2.54). Em camundongos, o isolado do L. ega manifestou sinais de agressividade e a raiva foi confirmada em animais inoculados IM e IN. A proporção de mortos observados em camundongos foi de 50.00% (PI 16.80 ± 2.20; PC 1.4 ± 0.54) e 30% (PI 14 ± 4.35; PC: 2.66 ± 0.57) respectivamente e o vírus CVS produziu mortalidade de 45.00% (PI: 6.30 ± 0.67; PC: 1.5 ± 0.70), 70% (PI: 7.14 ± 1.34; PC 2.28 ± 1.25) e 30% (PI:10.00; PC:1) pelas vias mencionadas acima, com quadro clínico de paralisia. O isolado de L. ega mostrou diferenças na proporção de mortos e quadro clínico furioso quando comparado com o CVS nos dois modelos animais. Os resultados sugerem que o contato com os morcegos insetívoros infectados pelo vírus da raiva representa um risco de transmissão da doença, por meio de ferimentos superficiais da pele provocadas pelas mordeduras ou ainda pela via respiratória, supostamente por meio de aerossóis. Pelo sequenciamento completo da proteína G viral do isolado do L. ega, foram observadas substituições na seqüência de aminoácidos nos sítios antigênicos AI, AII, assim como no domínio de fusão dependente de baixo pH. Os resultados obtidos, sugerem que as diferenças no comportamento biológico podem estar associadas às substituições encontradas na sequencia de aminoácidos da proteína G.The isolation of rabies virus (genotype 1) from the non-hematophagous bats is becoming frequent in heavy urbanized areas in Brazil. This work intended to investigate the pathogenicity of a Brazilian rabies virus isolate from the insectivorous bat Lassiurus ega, from PresidentePrudente-SP, comparing with the CVS/32 (Challenge Virus Standard) fixed rabies virus strain. The viruses were reactivated through intracerebral inoculation into mice and the pathogenicity experiments were made in hamsters and mice, challenged by intramuscular (IM), intradermal (ID) and intranasal (IN) routes and by superficial abrasion of skin. The presence of virus in the brain of animals manifesting the signs compatible with rabies was confirmed by the direct immunofluorescence test. For the evaluation of the pathogenicity, the clinical manifestations, incubation (IP) and clinical (CP) periods in days and the mortality were considered. In hamsters, the isolate of L. ega exhibited a furious form of rabies with total mortality rate of 2.60%, with following distribution: 2.08% IM (IP: 11 days; CP: 6 days) and 8.33% IN (IP: 10.66 ± 1.15 and PC: 7.33 ± 1.54). The presence of rabies virus in the CNS was detected only in animals inoculated through IM and IN routes. The CVS strain has provoked paralytic disease with a total mortality rate of 39.84% as the follow: 62.50% IM (IP 7.50 ± 2.33; CP: 5.13 ± 1.89), 78.12% ID (IP 9.13 ± 2.23; CP 3.88 ± 2.23) and 18.75% IN (IP 12.00 ± 2.77; CP 7.14 ± 2.54). In mice, the isolate of L. ega manifested signs of aggressiveness and rabies was confirmed in animals that were inoculated intramuscularly and intranasally. The total mortality rate observed in mice was 20%, by the IM route was 50% (IP 16.80 ± 2.20; CP 1.4 ± 0.54) and 30% by the intranasal route (IP 14.00 ± 4.35; CP: 2.66 ± 0.57) respectively. The CVS strain showed a total mortality rate of 45.00% and by the IM route, 100% (PI: 6.30 ± 0.67; CP: 1.5 ± 0.70), by the ID route, 70% (IP: 7.14 ± 1.34; CP 2.28 ± 1.25) and by IN, 30% (IP: 10, 00; C: 1.00) showing signs of paralysis. Compared to the CVS strain, the isolate of L. ega showed difference in mortality rate and signs of aggressiveness were found both in hamster and mouse model. The results suggest that the contact with the insectivorous bats infected with rabies virus would represent a risk of disease transmission, by means of superficial wounds of the skin inflicted by bites or by inhalation of aerosols. By the complete sequencing of the viral G protein of the isolate of L. ega, sequencings of amino acids substitutions were observed at antigenic sites AI, AII, as well as the in domain of fusion dependent on low pH. According to the results, differences in the biological behavior may be associated to the substitutions found in the amino acids sequence of the G protein.
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Sattler, Tatjana, Jutta Pikalo, Eveline Wodak, and Friedrich Schmoll. "Ability of ELISAs to detect antibodies against porcine respiratory and reproductive syndrome virus in serum of pigs after inactivated vaccination and subsequent challenge." Universitätsbibliothek Leipzig, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-216172.
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Background: In this study, six enzyme-linked immunosorbent assays (ELISA), intended for routine porcine reproductive and respiratory syndrome virus (PRRSV) herd monitoring, are tested for their ability to detect PRRSV specific antibodies in the serum of pigs after vaccination with an inactivated PRRSV type 1 vaccine and subsequent infection with a highly pathogenic (HP) PRRSV field strain. For this reason, ten piglets (group V) from a PRRSV negative herd were vaccinated twice at the age of 2 and 4 weeks with an inactivated PRRSV vaccine. Ten additional piglets (group N) from the sameherd remained unvaccinated. Three weeks after second vaccination, each of the piglets received an intradermal application of an HP PRRSV field strain. Serum samples were taken before first vaccination as well as before and 3, 7, 10 and 14 days after HP PRRSV application. All serum samples were tested for PRRSV RNA by reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) as well as for PRRSV antibodies with all six study ELISAs. Results: At the beginning of the study (before vaccination), all of the piglets were PRRSV antibody negative with all study ELISAs. They also tested negative for PRRSV RNA measured by RT-qPCR. From day 3 after HP PRRSV application until the end of the study, a viremia was detected by RT-qPCR in all of the piglets. On day 0 (day of HP PRRSV application), nine out of ten piglets of the pre-vaccinated group tested PRRSV antibody positive with one of the tested ELISAs, although with lower S/P values than after infection. On day 10 after HP PRRSV application, all study ELISAs except one had significantly higher S/P or OD values, respectively more positive samples, in group V than in group N. Conclusions: Only one of the tested ELISAs was able to detect reliably PRRSV antibodies in pigs vaccinated with an inactivated PRRSV vaccine. With most of the tested ELISAs, higher S/P values respectively more positive samples after PRRSV infection were seen in the pre-vaccinated group than in the non-vaccinated.
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Gers, Sophette. "A histological and immunohistochemical study of the lesions observed in desert warthogs (Phacochoerus africanus) and bushpigs (Potamochoerus porcus) following experimental challenge with CSF virus." Diss., University of Pretoria, 2011. http://hdl.handle.net/2263/31364.
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English: Common warthogs (Phacochoerus africanus) and bushpigs (Potamochoerus larvatus), were
experimentally infected with classical swine fever virus (CSFv) following the diagnosis of classical
swine fever (CSF) subtype 2.1 in 2005 in domestic pigs in South Africa. At that time, no data
regarding their susceptibility or the potential lesions in these wild suids were available. Seven
sub-adult warthogs and six bushpigs were captured, taken to the high containment facilities of the
Transboundary Animal Diseases Programme of the Agriculture Research Council (ARC) -
Onderstepoort Veterinary Research Institute, and infected intranasally with the South African
isolate. In each experiment, two in-contact control animals of the same species verified intraspecies
transmission, while two domestic pigs were used to demonstrate virus virulence and
viability. Surviving animals were euthanized 44 days post infection. Formalin-fixed tissue samples
collected from all experimental animals were evaluated for histological lesions. The warthogs,
which remained clinically normal throughout the study, developed histological lesions that were
inconsistently present and sometimes subtle. Three warthogs, including one in-contact control,
developed distinct perivascular lymphoplasmacytic cuffing in their brains. Subtle lesions included
scant lymphoplasmacytic infiltration of various organs, occasionally accompanied by perivascular
cuffing. In contrast, the bushpigs developed overt clinical signs similar to CSF in domestic pigs.
Four animals out of six, including two in-contact controls, died or were euthanized during the trial.
On post mortem examination, intestinal necrosis and ulceration, purulent rhinitis and pneumonia were present. Acutely affected animals developed lymphoid necrosis and depletion whilst
surviving individuals showed perivascular lymphoplasmacytic cuffing in multiple organs.
Immunohistochemical demonstration of CSFv antigen using a commercially available mouse
monoclonal antibody, WH303, revealed intense, widespread labelling in most tissues of all the
warthogs and bushpigs as well as the four domestic pigs used as controls during the trial. A wide
range of cell types and tissues reacted with the antibody. These included: mononuclear cells
(monocyte-macrophages, lymphocytes and plasma cells), follicular reticular cells, epithelial cells,
vascular endothelial cells, mesothelial cells, smooth muscle cells and fibroblasts.
Tissues that were labelled included tonsil, lymph nodes, spleen, third eyelid, adrenal gland,
urinary bladder, skin, liver, kidney, lung, certain cells within central nervous tissue like the choroid
plexus, various parts of the gastro-intestinal tract as well as glandular tissue like the pancreas
and salivary gland.
The tonsils were the most consistently labelled tissue, while no labelling was noted in myocytes of
skeletal or cardiac muscle.
From the present work, it was concluded that these wild Suidae are susceptible to CSFv and
intra-species transmission under experimental conditions can occur.Afrikaans: Wilde Afrika varke, nl. vlakvarke (Phacocoerus africanus) en bosvarke (Potamochoerus larvatus) was eksperimenteel infekteer met europese varkpes virus nadat die siekte in kommersiële mak varke diagnoseer is in 2005 (dit was tipeer as subtipe 2.1). Geen inligiting oor die vatbaarheid of potensiële letsels weens europese varkpes infeksie in hierdie wilde varke was beskikbaar nie. Sewe wilde onvolwasse vlakvarke en ses bosvarke is gevang, na die isolasie eenheid van die Onderstepoort Veterinêre Instituut se oor-grens siekte afdeling geneem en intranasal geïnfekteer met die Suid-Afrikaanse isolaat van 2005. Twee in-kontak kontrole diere van dieselfde spesie is gebruik in elke eksperiment om intra-spesie oordraging vas te stel en twee mak varke om virus lewensvatbaarheid en virulensie te demonstreer. Oorlewende diere is uitgesit na 44 dae. Formalien gefikseerde weefsel monsters is versamel van hulle, sowel as van diere wat uitgesit is tydens die eksperiment. Die vlakvarke was klinies normal regdeur die eksperiment, maar het wel histologiese letsels ontwikkel wat subtiel was en ook nie altyd teenwoordig in alle gevalle nie. Drie vlakvarke, waarvan een ‘n in-kontak dier was, het prominente limfo-plasmasitiese perivaskulêre flensing in hul breine ontwikkel. Subtiele letsels het klein hoeveelhede limfoplasmasitiese infiltrasies in verskeie organe en somtyds perivaskulêre flensing ingesluit. In teenstelling, het die bosvarke uitgesproke kliniese tekens soortgelyk aan Europese varkpes in mak varke, ontwikkel. Vier uit die ses diere, insluitend twee in-kontak diere is dood of uitgesit tydens die eksperiment. Met nadoodse ondersoek is daar intestinale nekrose en ulserasie, purulente rinitis en pneumonie gevind. Diere wat dood is, het limfoïede nekrose en limfoïede uitputting getoon, terwyl die oorlewende bosvarke perivaskulêre flensing met limfo-plasma selle in verskeie organe ontwikkel het. Immunohistochemiese demonstrasie van Europese varkpes virus antigen deur gebruik van ‘n kommersieël beskikbare muis monoklonale teenligaam, WH303, het duidelike wydverspreide kleuring in meeste weefsel van die die vlakvarke, bosvarke en mak varke getoon. ‘n Wye reeks van weefsel en sel tipes het met die teenliggam reageer naamlik: mononukliêre selle (monosietmakrofage en limfo-plasma selle), follikulêre retikulêre selle, epiteel, vaskulêre endoteel, mesoteel, gladde spier selle en fibroblaste. Weefsel wat gemerk is met die teenliggaam het ingesluit: mangels, limfknope, milt, derde ooglid, adrenaal klier, urienblaas, vel, lewer, nier, long, sekere selle in die sentrale senuwee stelsel, soos die koroïed pleksus, verskeie dele van die gastro-intestinale stelsel sowel as klier weefsel soos die pankreas en speekselklier. Die mangels was die mees konsekwent gemerkte weefsel, terwyl geen kleuring gevind is in miosiete van skelet of hartspier nie. Uit hierdie werk kon daar afgelei word dat vlakvarke en bosvarke vatbaar is vir Europese varkpes en dat intra-spesie oordraging plaasvind onder eksperimentele omstandighede.
Dissertation (MMedVet)--University of Pretoria, 2011.
Paraclinical Sciences
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Campos, Juliana Roberta. "EFFECTS ON SEMEN QUALITY AND ON ESTABLISHMENT OF PERSISTENT EQUINE ARTERITIS VIRUS (EAV) INFECTION IN STALLIONS FOLLOWING EXPERIMENTAL CHALLENGE WITH THE KENTUCKY 84 (KY84) STRAIN." UKnowledge, 2012. http://uknowledge.uky.edu/gluck_etds/6.
Full textAbstract:
Equine arteritis virus (EAV) is the causal agent of equine viral arteritis (EVA), a disease of equids. Following EAV infection, up to 70% of stallions may become carriers and continuously shed the virus in their semen for varying time periods. The long-term carrier stallion has an important role in the transmission and maintenance of EAV in horse populations. Recently, it has been demonstrated a correlation between in vitro susceptibility of CD3+ T lymphocytes to EAV infection and establishment of long-term persistent infection among stallions following natural infections. In this study, we investigated whether stallions with in vitro EAV susceptible CD3+ T lymphocytes are at higher risk of becoming long-term carriers compared to those with the resistant phenotype following experimental infection with the KY84 strain of EAV. Furthermore, we investigated whether there is a significant effect of EAV infection on semen quality during acute phase of the infection. The data suggested that the establishment of the long-term carrier state seems to be associated with the in vitro CD3+ T lymphocyte susceptible phenotypes and that reduced semen quality resulted from the combined effect of fever and scrotal edema observed following EAV infection rather than the direct effect of the virus.
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Baloglu, Simge. "Assessment of the Expression of Brucella Abortus Heat Shock Protein, Groel, in Vaccinia Virus to Induce Protection Against a Brucella Challenge in Balb/C Mice." Thesis, Virginia Tech, 1997. http://hdl.handle.net/10919/36943.
Full textAbstract:
B. abortus is an intracellular facultative bacterial pathogen which causes abortion in cattle and undulant fever in humans. Cattle vaccines such as B. abortus strains 19 and RB51 are live vaccine strains which protect approximately 75% of the vaccinated animals. No effective vaccines are available for the prevention of brucellosis in humans. We are developing vaccinia virus recombinants expressing various B. abortus proteins to prevent brucellosis in susceptible mammalian species. In this work the B. abortus groEL gene encoding the antigenic heat shock protein GroEL was subcloned into vaccinia virus via homologous recombination. Expression of the GroEL protein in vaccinia infected cells in-vivo was confirmed by immunoblotting. Groups of 5 female BALB/C mice were injected with the vaccinia recombinant or appropriate positive and negative control vaccines. Mice were bled and their humoral immune responses assessed. In addition, mice were challenged with virulent B. abortus strain 2308 and protection measured by the rate of splenic clearance of live Brucella. In spite of demonstrating specific GroEL antibodies in recombinant vaccinia injected mice, no significant level of protection was demonstrable. Preliminary lymphocyte transformation assays were carried out to establish if a cell mediated immune response to GroEL was induced in the vaccinated animals.Master of Science
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Bwala, Dauda Garba. "Challenge studies in chickens to evaluate the efficacy of commercial Newcastle disease vaccines against the strains of Newcastle disease virus prevalent in South Africa since 2002." Pretoria : [s.n.], 2010. http://upetd.up.ac.za/thesis/available/etd-02262010-123322/.
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Sribanditmongkol, Vorachai. "Effects of Psychological Stress on Glucocorticoid Sensitivity of Inflammatory Response to Influenza Vaccine Challenge in Healthy Military College Students." The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1366195257.
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Cunha, Elenice Maria Sequetin. "Caracterização genética de amostras do vírus da raiva isoladas de morcegos. Avaliação da patogenicidade e proteção cruzada em camundongos." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/10/10134/tde-30082007-150537/.
Full textAbstract:
Vírus da raiva provenientes de 23 morcegos de espécies hematófagas, frugívoras e insetívoras foram caracterizados geneticamente pelo seqüenciamento completo da região que codifica a nucleoproteína N. A análise filogenética das seqüências, incluindo lyssavirus e isolados de morcegos do Chile e Estados Unidos, mostrou que os diferentes isolados do vírus da raiva foram de modo geral segregados em quatro grupos genéticos distintas: morcegos hematófagos, morcegos insetívoros 1, 2 e 3. Os morcegos insetívoros 1 constituiram-se por isolados de Eptesicus furinalis: BR-EF1, BR-EF2, BREF3, BR-EF-4, BR-EA1 e BR-NL2; os morcegos insetívoros 2 consistiram de isolados de Molosssus spp: BR-MM1, BR-MM2 e BR- MA1 e os morcegos insetívoros 3 isolados de Nictinomops laticaudatus: BR-NL1 e BR-NL3. A homologia de nucleotídeos entre cada grupo de morcegos insetívoros 1, 2 e 3 foi maior que 99%, 97% e 99%, respectivamente. O grupo de morcegos hematófagos foi representado pelos isolados de: 3 morcegos hematófagos Desmodus rotundus (BR-DR1, BR-DR2 e BR-DR3); 5 morcegos frugívoros Artibeus lituratus BR-AL1, BR-AL2, BR-AL3, BR-AL4 e Artibeus planirostris BRAP1; 2 morcegos insetívoros (BR-MR1 e BR-EA2) e 2 de espécies não identificadas (BR-BAT1 e BR-BAT2). Entre as amostras seqüenciadas foram selecionadas cinco (BR-EF1, BR-NL1, BR-AL3, BR-MM1, BR-DR1) e um isolado de cão (BR-C) para os estudos de patogenicidade em camundongos albinos suíços inoculados pela vias intracerebral (IC) e intramuscular (IM). Todas as amostras quando inoculadas em camundongos pela via IC apresentaram-se patogênicas, provocando a morte dos mesmos num período de 4 a 14 dias pós-inoculação. No entanto, 500DLIC50 das mesmas amostras inoculadas pela via IM levaram a uma mortalidade de camundongos de: 60% (BR-DR1); 50% (BR-C, BR-NL); 40% (BR- AL3); 9,5% (BR-MM1); 5,2% (BR-EF10). As mesmas amostras foram utilizadas para a verificação de proteção cruzada, conferida por vacina comercial de uso animal, de camundongos que receberam uma ou duas doses de vacina pela via subcutânea (SC) e desafiados pelas vias IC e IM. Camundongos inoculados com duas doses de vacina foram protegidos quando desafiados pela via IC, com todas as amostras testadas. Quando os camundongos receberam uma dose da mesma vacina houve proteção parcial daqueles desafiados com as amostras de vírus PV e BR-C. Houve proteção de 100% dos camundongos desafiados pela via IM, com exceção daqueles vacinados com uma dose de vacina e desafiados com a amostra PV que apresentaram um índice de 66% de sobreviventes. Os resultados indicam a possibilidade de existir variantes do vírus da raiva espécies específicas circulando em morcegos. Sugerem ainda, que espécies de morcegos hematófagos, frugívoros e insetívoros compartilham o mesmo polimorfismo de vírus. A vacina comercial contra a raiva contendo vírus inativado e de uso veterinário protegeu os camundongos contra o desafio com as diferentes amostras testadas, sugerindo que as vacinas usualmente utilizadas são efetivas no tratamento profilático da raiva transmitida por morcegos, apesar da marcada diferença de neurovirulência dos diferentes isolados quando inoculados em camundongos pela via IM.Twenty-three rabies viruses isolated from hematophagous, frugivorous and insectivorous bats were characterized genetically by complete sequencing of the region coding the nucleoprotein N. The phylogenetic analysis of the sequences, including the lyssavirus and the bat isolates from Chile and USA revealed that the isolates were segregated into four distinct genetic lineages: those related to the vampire bats and to the insectivorous bats 1, 2 and 3. The isolates related to the insectivorous bats 1 were from the Eptesicus furinalis: BR-EF1, BR- EF2, BREF3, BR-EF-4, BR-EA1 e BR-NL2; those of the insectivorous bats2 included the isolates from Molosssus spp: BR-MM1, BR-MM2 and BR-MA1 and the group 3, by the isolates from the Nictinomops laticaudatus: BR-NL1 and BR-NL3. The homology among each group of the insectivorous bats 1, 2 and 3 were greater than 99%, 97% and 99%, respectively. The lineage related to vampire bats was represented by three isolates from the D. rotundus (BR-DR1, BR-DR2 e BR-DR3); five from the fruit bats Artibeus lituratus (BR-AL1, BR-AL2, BR-AL3, BR-AL4) and Artibeus planirostris (BRAP1); two from insectivorous bats (BR-MR1 and BR-EA2) and two from unidentified species (BR-BAT1 and BR-BAT2). Among the sequenced amples, five bat isolates (BR-EF1, BR-NL1, BR-AL3, BR-MM1, BR- DR1) and one dog isolate (BR-C) were selected for the study of their pathogenicity in Swiss mice, inoculating through intracerebral (IC) and intramuscular (IM) routes. All the isolates, when inoculated via IC, were pathogenic, provoking death in 4 - 14 post inoculation days. However, mice inoculated with 500ICLD50 of the same isolates through IM route were found with different death rates: 60.0% (BR-DR1); 50.0% (BR-C, BR-NL); 40.0% (BR-AL3); 9.5% (BR-MM1) and 5.2% (BR-EF10). The same isolates were used for the assessment of cross protection conferred by a commercial vaccine of veterinary use. The mice were vaccinated subcutaneously, receiving either one or two shots of vaccine, and challenged through IC and IM routes. Mice receiving two shots were protected against all the isolates, when challenged intracerebrally. Mice receiving one shot were found only partially protected against the challenge with the fixed PV strain and BR-C isolate. Mice challenged intramuscularly showed 100.0% of protection, with the exception of those vaccinated with one dose and challenged with PV strain, which were found with 66.0% of survivors. These results indicate the possibility of the existence of rabies virus variants circulating in different species of bat population. The data also suggest that the vampires, frugivorous and insectivorous bats share the same lineage of rabies viruses. The commercial vaccine has protected the mice against the challenge with different rabies virus isolates, suggesting that the vaccines usually employed in the field are effective, although some marked difference in neurovirulence by IM inoculation was found among the isolates tested.
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Abele, Rommie Navylia. "Challenges of Aging With the HIV Virus and Comorbidities." ScholarWorks, 2018. https://scholarworks.waldenu.edu/dissertations/4704.
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Since the introduction of antiretroviral therapy, the survival rate of infected HIV patients has been on the rise with a predicted increase by 2030. The longer a person lives with the virus, the more prone to HIV-associated chronic diseases he or she becomes, but it is not clear whether these diseases are solely from aging with the virus or from long-term use of antiretroviral therapy. Scientists demonstrated that the introduction of antiretroviral therapy led to an increased life expectancy yet early onset of comorbidities; however, they failed to address the challenges that people 50 years old or older face, as well as other factors affecting their quality of life. The purpose of this study, driven by both social constructivism as well as the advocacy worldview, was to explore the lived experiences of participants older than 50 living with HIV to gain an understanding of how long-term use of antiretroviral therapy relates to the onset of comorbidities, which would lead to a new understanding of the challenges they face. These findings could give healthcare providers insights on the population in question, their challenges, and how to better address their concerns. The methodology of the study was a phenomenological approach; data were collected through 10 participant responses during recorded telephone interviews. The recorded data were transcribed before being analyzed using Nvivo software. The results indicated that these participants live in daily survivorship filled with constant struggle between a series of comorbidities that develop overtime. Additionally, their journey is not only coupled with unmet needs of today but also with uncertainties of tomorrow. The findings can improve the current social conditions of those who are older and suffering from HIV by providing information to healthcare professionals who can improve or maintain the health of this population.
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DeBernardis, Justin R. "Phenotypic changes in dendritic cells when challenged with cowpox virus." [Gainesville, Fla.] : University of Florida, 2004. http://purl.fcla.edu/fcla/etd/UFE0007340.
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Thesis (M.S.)--University of Florida, 2004.Typescript. Title from title page of source document. Document formatted into pages; contains 49 pages. Includes Vita. Includes bibliographical references.
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Hoopes, Justin Darrel. "Mechanisms of Induced Cell Death in Bluetongue Virus Challenged Human Cell Lines." DigitalCommons@USU, 2009. https://digitalcommons.usu.edu/etd/252.
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Bluetongue virus (BTV) is a pathogenic member of the Reoviridae family. BTV does not cause disease in humans, but is capable of selectively infecting and killing certain transformed human cell lines. Understanding BTV's oncotrophism may lead to new therapeutics for treating cancer. This study focused on the underlying mechanisms of BTV-induced cell death in carcinoma cell lines. It was our hypothesis that BTV infects human carcinoma transformed cells, produces mRNA and protein, induces a strong inflammatory response, induces mitogen activated protein kinase (MAPK)-based pro-apoptotic signaling, inhibits PKB-based signaling, and eventually kills the cell by inducing apoptosis.
Three carcinoma cell lines (A498, HEP-G2, and A549) were independently infected with BTV. In each cell line we determined: (1) cell viability over the course of infection; (2) BTV induced cytokine expression profile and magnitude of expression; (3) BTV viral RNA expression profile and magnitude of expression; (4) BTV viral protein expression profile and magnitude of expression; (5) changes in BTV induced cell death and cytokine expression in cells with protein kinase B (PKB), p38-MAPK, extracellular receptor kinase (ERK-1/2), stress-activated protein kinase (SAPK-JNK), Src kinase, platelet-derived growth factor receptor (PDGFR) kinase, epidermal growth factor receptor (EDGFR) kinase, or Janus kinase (JAK) activity inhibited; (6) intracellular changes in PKB, p38-MAPK, ERK-1/2, and SAPK-JNK phosphorylation as a result of BTV infection; and (7) BTV-induced changes in tyrosine phosphorylation.
We determined that BTV infects and kills all three cell lines in a cell line dependent manner. Relative cell death between cell lines was proportional to cytokine expression, but inversely proportional to viral protein expression. Only tyrosine kinase inhibitors influenced BTV-induced cell death and cytokine expression. Both A498 and A549 cells constitutively expressed phosphorylated PKB and p38 MAPK, of which both were de-phosphorylated during BTV infection. Tyrosine phosphorylation remained active, with elevated tyrosine phosphorylation exclusively in infected cells.
We conclude that BTV-induced cell death and cytokine expression are a function of the cell's response to infection and are directly related through intracellular signaling. These pathways are only partially poly I:C inducible, but include PKB and tyrosine kinase signaling.
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Miniard, Brock M. "Expression of Inflamatory Response Genes in Ferrets Challenged with H5N1 Avian Influenza Virus." Wright State University / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=wright1339452079.
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Amuge, Teddy. "Genome-wide transcriptome analysis of cassava challenged with Ugandan cassava brown streak virus (UCBSV)." Thesis, University of Pretoria, 2019. http://hdl.handle.net/2263/72121.
Full textAbstract:
Cassava is staple to millions in Africa, yet cassava brown streak disease (CBSD) greatly threatens cassava production. This study reports the mechanism of cassava’s resistance to CBSD using Ugandan cassava brown streak virus (UCBSV), one of the two CBSD-causal virus species. In a green house, five varieties: Albert, Kiroba, Mkombozi, Namikonga and NDL06/132 were analysed for response to UCBSV at 20 time points. In the first experiment, Albert and Namikonga were compared. In the second experiment, all five varieties were studied. Plants were phentyped for foliar and root symptoms of CBSD, virus titre was measured using qRT-PCR while RNAseq and QuantStudio were used to determine gene expression. Virus infected plants of susceptible variety (Albert) developed clear leaf symptoms and necrotic storage roots. UCBSV-infected plants of Namikonga (resistant) showed minimal leaf symptoms and storage roots were non-necrotic. UCBSV titre was highest in susceptible variety (Albert), and very low in the resistant variety (Namikonga). More genes were differentially expressed in Namikonga (10,028) compared to Albert (688). In Namikonga, highest expression was recorded at 2 dag and 5 dag, when only two genes were differentially expressed in Albert. GO terms for phosphorelay signal transduction, ribosome and elongation factors were enriched in Namikonga and none in Albert. In another experiment, UCBSV-infected storage roots from Kiroba were non-necrotic. Defence genes identified in Kiroba were similar to Namikonga’s, except that in Kiroba, genes were highly expressed at 1 dag and 51 dag. One storage root of Mkombozi developed a necrotic spot. Mkombozi had no distinct pattern of defence-gene expression as seen in Kiroba and Namikonga. Varieties NDL06/132 and Albert were susceptible, and showed limited numbers of differentially expressed genes. Therefore, Kiroba and Namikonga are resistant to CBSD. The resistance mechanism involves up regulation of known defence proteins, and restricted multiplication of UCBSV in infected plants.Thesis (PhD)--University of Pretoria, 2019.
Bill and Melinda Gates Foundation & University of Pretoria
Plant Science
PhD
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Nqaba, Nokuthula. "An exploration into the challenges teachers face in implementing HIV/AIDS initiatives and programmes in primary schools: a case study of two primary schools in Nyanga Township." Thesis, University of the Western Cape, 2014. http://hdl.handle.net/11394/4129.
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Magister Artium - MATwenty years into democracy and South Africa like many of the world‟s nations still faces manifold challenges in dealing with HIV/AIDS. This disease affects millions of people in various forms; socially, economically and politically. HIV/AIDS is considered to be a global pandemic (UNAIDS, 2011). The largest group at risk appears to be people between the ages of 15 and 24. One crucial way of dealing with this pandemic is through education since the emphasis is on prevention. It is against this background that this study explored the challenges teachers face in implementing HIV and AIDS initiatives and programmes in two primary schools in Crossroads, in the Nyanga region, in the Western Cape. It appears that research on this topic is not normally carried out in primary schools. I therefore start from the premise that literature on the topic, especially in this empirical field (primary schools), is limited. The conceptual lens used to understand this complex issue is the Bio-ecological Systems Model of Bronfrenbrenner (1977). Teachers operate within various contexts and their teaching is often influences by their experiences, knowledge and attitudes (Tayob, 2010:3). Furthermore, it appears that the implementation of HIV/AIDS initiatives and programmes at primary school level is dependent on the relationship between many systems. The complexities of understanding these relationships warrant the use of this model within this study. Methodologically, this study employed a qualitative case study research design to investigate this contemporary phenomenon. I employed in-depth qualitative data collection procedures which included: a questionnaire, semi-structured interviews, and document analysis. The findings indicate that educators are seriously constrained by lack of support from school management and parents when engaging in HIV/AIDS initiatives or programmes at respective primary schools. The study also reveals that educators are not well trained to offer counselling to deal with HIV/AIDS related matters and it becomes worse with those infected. In addition, this study reveals that embedded cultural beliefs play a huge impeding factor in attempts to participate in HIV/AIDS initiatives and programmes, which are aimed to empower both educators and learners. The study therefore recommends a need for stronger financial muscle and support from schools management team to ensure that time set aside for life orientation classes be utilised effectively for the benefit of learners with priority on HIV/AIDS studies and initiative programmes. A strategic inclusion of parents, religious and traditional leaders with the Department of Basic Education and all relevant partners is very critical to achieve the fight against the struggle with HIV/AIDS through means of education at all levels within the sector and beyond.
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Kelakazola, Henry Ilunga Kasongo. "W.H.O recommended infant feeding options: assessment of the challenges faced by HIV positive mothers in Mongu District, Zambia." Thesis, UWC, 2008. http://hdl.handle.net/11394/2869.
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Magister Scientiae (Biodiversity and Conservation Biology) - MSc (Biodiv and Cons Biol)W.H.O infant feeding options are presented as a package in the prevention of HIV transmission from mother to child. These infant feeding options are namely exclusive breastfeeding, replacement feeding and other options such as wet nursing by a tested HIV negative woman and heat treated breast milk. However, in Zambia, like many other poor countries, the cultural attitude towards breastfeeding is that the breastfeeding period generally goes up to two years. This traditional way of feeding is so much rooted in local culture that any cessation of breastfeeding or any introduction of alternative feeding would be a source of concern at community and family levels. In addition, it is a well known fact that stigma and discrimination are still high in the country. It is with this background that we decided to carry out a study in Mongu district which aimed at assessing HIV positive mothers’ knowledge of WHO infant feeding options and looking at the challenges they face vis-à-vis these recommended feeding options. DATA COLLECTION METHODS A total of 10 experienced nurses, who have been working in the HIV/AIDS programme for more than 15 years, were trained in data collection. During home visit, semistructured questionnaires were used during face- to- face interviews of each HIV positive mother who voluntarily took part in the study. SAMPLING AND SAMPLE SIZE Systematic sampling technique was used to constitute our study sample. With this technique, a complete list of 5317 HIV positive mothers was constituted by listing all HIV positive mothers whose names were in the registers of PMTCT at the selected health institutions, and who had infants whose ages ranged from 6 months to 2 years. 1636 HIV positive mothers had babies whose ages were ranging between 6 months and 2 years. Out of the 1636 we selected randomly the first participant from the complete list, and then we went on selecting every 8th HIV positive mother up to the time we constituted a sample of 200 participants. Thereafter, the selected HIV positive mothers were visited individually in their respective households for interview by trained interviewers. During home visit, 5 selected participants declined to take part in our study while 195 HIV mothers voluntarily accepted to be interviewed. RESULTS Analysis of data collected from 195 HIV positive mothers revealed that 144 study participants or 73.8 %( 95% C I 67.6-80%) of all participants knew their status through the PMTCT programme where the “opt out” approach was used to routinely screen pregnant women for HIV during ante natal visit or when admitted to labour wards. It was also established that the assessment of knowledge among study participants of exclusive breastfeeding period was good. 96.9 %( 95% CI 95.66-98.14%) of participants stated that 6 months was the recommended duration for exclusive breastfeeding when the mother is HIV positive while only 3.07 %( 95% CI 0.65-5.49%) said that exclusive breastfeeding should go beyond 6 months. It was discovered that the majority of HIV positive mothers or 166 participants representing 85.1%(95% CI 80.1-90.1%) who participated in our study considered mixed- feeding as not appropriate for infant born from HIV positive mothers while 29 participants or 14.8%(95% CI 9.8-19.8%) said that mixed feeding was recommendable. It was also found that 95 participants representing 48.7 %( 95% CI 41.6- 55.7%) opted for exclusive breastfeeding, 61 participants or 31.2% (95% CI 24.7-37.7%) participants opted for formula milk while 39 or 20 %( 95% CI 14.4- 25.6%) of participants were mixed-feeding. It was discovered that 118 participants had breastfed. Among them, 53.4 %( 95% CI 46.4-60.4%) participants said that they had breastfeed for up to 6 months while 46.6 %( 95% CI 43-50.2%) said they had breastfeed for more than 6 months. Among those who had breastfed for more than 6 months, 58.1 %( 95% CI 54.6-61.6%) said that they had done so because of financial constraints; 21.8 %( 95% CI 16-27.6%) for fear of discrimination and stigmatization; and 20 %( 95% CI 14.4-25.6%) for fear of discrimination and stigmatization and financial constraints. We also discovered during our research that for the majority of study participants or 81.5%, the decision to opt for one of the infant feeding options was a product of discussion between the HIV positive mothers and other persons such as the husband, friends, relatives and health care provider. CONCLUSION In our study we discovered that though the knowledge of PMTCT and WHO infant feeding options among study participants was good, fear of stigmatization, discrimination and abandonment was high among interviewees. This fear explains why the implementation of WHO infant feeding options is still a serious challenge amongst HIV positive mothers in Mongu, as many HIV positive mothers do not want to be seen in the community as people carrying the virus. It is also for the same reason that our study participants had to choose people to whom to talk to about their HIV positive status and with who to discuss their chosen infant feeding options. Further, due to the high level of poverty among Mongu residents, financial constraint was another major challenge in the implementation of WHO recommended infants feeding options.
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Chimatira, Raymond. "Challenges, barriers and opportunities in integrating TB/HIV services in Tsandi District Hospital, Namibia." Thesis, University of Western Cape, 2012. http://hdl.handle.net/11394/3308.
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Magister Public Health - MPHBACKGROUND: Namibia has generalised Human Immunodeficiency Virus (HIV) and tuberculosis (TB) epidemics. In response to the TB/HIV co-epidemics in Namibia, the Ministry of Health and Social Services approved a policy of TB/HIV collaborative activities at national level and the integration of TB/HIV services at the point of service delivery. The present study explored barriers and facilitators of integration of TB and HIV service delivery in Tsandi District Hospital, which lies in rural northern Namibia. It focused on understanding the perspectives of healthcare workers and service users on integration of TB and HIV services at the health facility. AIMS & OBJECTIVES: The study aimed to describe the barriers, facilitators, and opportunities of integrated TB/HIV service delivery in Tsandi District Hospital. The specific objectives were: to describe the staffing and support systems in place for the integration of TB/HIV care; to describe the perceptions and experiences of integrated TB/HIV care by the health care workers, management and co-infected clients; and to describe the factors that facilitate or hinder the integration of TB/HIV services in the district from the point of view of district hospital managers, health care workers and co-infected clients. METHODS: The study used a descriptive qualitative study design with semistructured key-informant interviews conducted with five healthcare managers and senior clinicians and focus group discussions with 14 healthcare workers and five TB/HIV co-infected patients, supplemented by non-participant observation in Tsandi district hospital over two weeks between May – June 2011. Sessions were audiorecorded, transcribed, and thematically analysed. RESULTS: Several factors influenced whether and to what degree Tsandi district hospital was able to achieve integration of TB and HIV services. These are: (1) model of care and nature of referral links; (2) the availability and use of human resources and workspace; (3) the system of rotating staff among departments in the hospital; (4) the supply and mode of providing medicines to patients; (5) information systems, recording and reporting arrangements; (6) and the amount of follow-up and supervision of the integrated services. The main suggested barrier factors are: (1) poor communication and weak referrals links between services; (2) inadequate infrastructure to encourage and deliver TB and HIV care; (3) staff shortages and high workload; (4) lack of training and skills among healthcare workers; (5) financial constraints and other socioeconomic challenges; and (6) fragmented recording and reporting systems with limited data use to improve service delivery. The four main facilitating factors are: (1) positive staff attitudes towards TB/HIV integration; (2) common pool of staff managing different programmes; (3) joint planning and review of TB and HIV activities at the ARV Committee; and (4) informal task sharing to alleviate healthcare worker shortages. CONCLUSIONS: This study recommends that the district build on the current facilitators of integration, while the inhibitors should be worked on in order to improve the delivery of TB/HIV services in the district. Simple and practical recommendations have been made to address the some of the barriers at district level. It is hoped that these will inform future planning and review of the current model of care by the District nagement Team.
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Kumakech, Edward. "Human immunodeficiency virus (HIV), human papillomavirus (HPV) and cervical cancer prevention in Uganda : prevalence, risk factors, benefits and challenges of post-exposure profylaxis, screening integration and vaccination." Doctoral thesis, Örebro universitet, Institutionen för hälsovetenskap och medicin, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-44517.
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Sanga, Erica Samson. "Expectations and experiences of Hiv vaccine trial participants at the Mbeya Medical Research Programme in Mbeya, Tanzania 2006-2007." Thesis, University of the Western Cape, 2010. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_2027_1308634801.
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A qualitative descriptive study approach was used to gather the required information. The sample for this study was drawn from an existing group of volunteers who participated in the vaccine trial at Mbeya Medical Research Centre in 2006-2007. A purposive sampling method was used to select respondents because they had had experience of being participants in a HIV vaccine trial. Twenty audio recorded in-depth interviews were conducted. The interviews were conducted at the clinic during their routine follow up visits. An open ended interview guideline was used to guide the discussion to elicit the required information from the respondents. The data was transcribed, translated and then analyzed by both content and thematic approach. Ethical procedures were observed, including getting permission from the local ethical committee in Mbeya region and participants were given an informed consent form to read and sign before starting the interview.
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Rouamba, Ky-Zerbo Odette. "Enjeux et limites du conseil et du test du VIH (CTV) dans un pays de basse prévalence en Afrique Subsaharienne : cas du Burkina Faso." Thesis, Montpellier, 2016. http://www.theses.fr/2016MONTT035/document.
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Introduction. Des traitements efficaces permettent la prise en charge des personnes vivant avec le VIH (PVVIH) et la prévention. Cependant, seulement 55% des PVVIH connaissent leur statut et ce taux est encore plus faible pour les pays de l’Afrique de l’Ouest et du Centre (35%). Afin d’accroître l’offre de Conseil et Test pour le VIH (CTV), l’OMS a publié en juillet 2015 un guide consolidé basé sur des études, dont certaines ont été réalisées en Afrique Subsaharienne. Et très peu d’entre elles concernent les pays à faible prévalence du VIH, notamment l’Afrique de l’Ouest francophone. Cette thèse a pour objectif général d’analyser les enjeux et les limites des politiques et programmes de CTV dans les pays africains de basse prévalence VIH, à partir de la situation du Burkina Faso, et de proposer de nouvelles mesures pour développer l’offre de CTV.Méthodes. Deux études ont été conduites. La première portait sur les motivations et les obstacles à la pratique du test VIH. Elle a été menée dans le cadre du projet « Multi-country African Testing and Counselling for HIV » (MATCH) portant sur quatre pays (Burkina Faso, Kenya, Malawi, Ouganda). Au Burkina Faso, l’étude a été conduite en 2008-2009 en milieu urbain (Ouagadougou) et rural (Dédougou) dans des sites sélectionnés selon leur niveau de fréquentation. Des approches quantitatives et qualitatives ont été utilisées.La deuxième étude a été conduite en 2015 auprès des acteurs et des décideurs du CTV au niveau national, et visait à analyser leurs perceptions des directives publiées par l’OMS en 2015. Un outil de collecte des données expliquant les changements a diffusé par voie électronique. Les réponses ont été analysées de manière quantitative et qualitative.Résultats. L’offre du CTV est basée au Burkina Faso sur des documents validés en 2008.L’analyse de l’utilisation du test à l’initiative du client a montré que les femmes étaient les plus nombreuses (58,5%). Cependant les hommes (p=0,02), les 18-34 ans (p=0,01), et les plus scolarisés (p=0,001) semblaient utiliser plus précocement les services.. En analyse multivariée, ces catégories utilisaient plus les campagnes. Les signes ou symptômes liés au VIH motivaient le test chez les femmes (p=0,008), les 35 ans et plus (p<0,001) et les non scolarisés (p<0,001) qui sollicitaient plus le test en sites fixes. L’utilisation du CTV pendant la campagne était associée au désir de connaître le statut (p<0,001), tandis qu’en dehors des campagnes, l'état de santé de l’utilisateur, la maladie ou le décès du partenaire était le principal motif (p=0,001). Aussi 61% des utilisateurs avaient réalisé 2 tests et plus. Dans une analyse multivariée, l’utilisation répétée du CTV par les personnes séronégatives était associée à la scolarisation (au moins le secondaire), au jeune âge et pour les PVVIH à la résidence en milieu urbain.Les prestataires déclaraient être confrontés à des difficultés logistiques et matérielles pour offrir adéquatement le CTV. Il en résultait une faible qualité des services, notamment un conseil post test dispensé partiellement, et une faible référence des PVVIH. Celles-ci avaient un vécu de stigmatisation élevé, soit 46% de stigmatisation interne, 40% dans les relations interpersonnelles et 11% dans les services de santé. Les décideurs et acteurs ont trouvé la plupart des directives de 2015 pertinentes, mais sont pessimistes sur leur faisabilité.Conclusion. Ce travail a identifié les limites du CTV au Burkina Faso et donne des éléments significatifs pour les pays africains de basse prévalence. Dans un contexte de raréfaction des ressources, l’accès équitable au CTV nécessite l’identification de stratégies innovantes. Le renforcement des capacités des prestataires pour une offre globale de services de qualité est nécessaire. La lutte contre la stigmatisation devrait être intensifiée. La prise en compte des avis des experts permettra la révision des documents nationaux et leur adaptation selon les directives OMSBackground. Treatments are effective for people living with HIVAIDS (PLWHA) care and prevention. However, only 55% of PLWHA are aware of their status. This rate is lower in Central and West Africa (35%). In July 2015, WHO published new guidelines on HIV testing. In Sub-Saharan Africa, there are many studies which results are used to define policies and guidelines on HIV testing at the international level. Few of them are implemented in low HIV prevalence countries, notably French-Speaking West Africa. The overall objective of this thesis is to analyze the challenges and limitations of HIV testing and counselling (HTC) policies and programs in low prevalence countries, over the situation in Burkina Faso and propose new measures to increase the access to HTC services.Methods. Two studies have been conducted. The first one was carried out in the « Multi-country African Testing and Counselling for HIV » (MATCH) project which was implemented in four countries (Burkina Faso, Kenya, Malawi, Uganda). It aimed to analyze the motivations and barriers to HTC services practices by users, non-users and providers. In Burkina Faso, the study was carried out in Urban (Ouagadougou) and rural (Dédougou) areas in 2008-2009. In each locality, study sites (client initiated testing and provider initiated testing sites) were chosen, given the level of utilization. Quantitative and qualitative methods were used. The second study was conducted in 2015, with HTC providers and decision makers at national level. The objective was to analyze their perceptions on WHO 2015 guidelines. A data collection tool explaining the changes introduced in the guidelines has been designed and transmitted via electronic means. Their opinions were analyzed.Results. Guidelines for HTC in Burkina Faso were from 2008. In client initiated testing sites, there were more women (58.5%). However, men (p=0.02), 18-34 years old (p=0.01), and the more educated ones (p=0.001) appeared to have used early services. In multivariate analysis, those categories used often campaigns. Women (p=0.008), 35 years of age and over (p<0.001) and less educated people (p<0.001) sought more often the test in fixed sites. The use of HTC services during campaigns is associated with the desire to know one's HIV status (p<0.01), while outside of campaigns, the health status of the user, the illness or the partner's death was the main concern (p=0.001). Campaigns are associated with the hope of knowing one’s HIV status (p<0.001). There were 61% of users who were repeat testers (2 or more tests). In a multivariate analysis, repeat testing for HIV negative people was associated with higher education, young age and for PLWHA living in urban areas. HTC Providers declared that they faced logistic and material challenges. It resulted in a low quality of services, in particular post-test counselling sessions that were partially done and a low effective reference of PLWHA towards care services. HIV stigma was found to be very high (46% of PLWHA faced internal stigma, 40% of interpersonal stigma, and 11% in health services). Decision-makers and providers have found most of the 2015 guidelines relevant, but were pessimist about their feasibility.Conclusion. This work has identified limitations of HTC at the individual, community, health services and institutional levels in Burkina Faso, and provides significant elements for African low prevalence countries. Given the scarcity of resources, there is a need for innovative strategies for equitable access to HTC, in order to attract more men, and test earlier women, less educated and 34 years or older. Strengthening the capacity of service providers to include a comprehensive range of quality services is necessary. All the aforementioned should be supplemented by the fight against stigma. Paying attention to national HTC experts’ opinion will help for national guidelines review and adapt them to WHO guidelines
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JHENG, YU-HAN, and 鄭郁涵. "Challenge model for porcine reproductive and respiratory syndrome virus." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/5krnyy.
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碩士國立屏東科技大學
獸醫學系所
106
Porcine reproductive and respiratory syndrome (PRRS) is categorized as one of the highly contagious and economically damaging swine diseases. In year 1991, the first reported outbreak emerged and caused heavy economic losses among the swine farms in Taiwan. Pigs naturally infected or experimentally challenged with PRRS virus (PRRSV) have been shown the characteristics of persistent infection. This disease became the major cause of death and culling of pigs in swine industry. The purpose of this experiment is to establish a PRRSV challenge model in pigs. In the pilot animal challenge test, the PRRSV inoculum strain YMX5 was found to be contaminated with Mycoplasma. Therefore, by challenging pigs with specimens collected from original sick pigs in the field, we successfully re-isolated Mycoplasma free PRRSV strains YMX5-1, YMX5-2 and YMX5-3 from the sera of inoculated pigs using porcine alveolar macrophages. The PRRSV strain YMX5-1 was then selected as the inoculum for further study. Pigs inoculated with YMX5-1 showed obvious and typical clinical signs and pathological changes of PRRSV infection. The protective efficacy of a PRRSV subunit vaccine was then evaluated using the above established challenge model in pigs. Results showed that PRRSV YMX5-1 inoculation resulted in the induction of typical clinical signs and pathological changes of PRRS, and high PRRSV concentrations in serum and tissues in pigs in both control and vaccine groups. There was no significant difference (P>0.1) between the two groups. The results indicate that the vaccine cannot effectively protect pigs from PRRSV infection. The above results showed that this study has successfully established a typical and reproducible PRRSV challenge model. The model can be applied to the development of vaccine and related researches Keywords: porcine reproductive and respiratory syndrome, virus, challenge model
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Paik, Daniel Hyunwook. "Lung localized protective responses to heterosubtypic influenza challenge." Thesis, 2020. https://doi.org/10.7916/d8-ff60-9c21.
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Influenza A virus (IAV) is one of the most ubiquitous respiratory viruses in the world, causing significant disease burden in the United States and abroad. Current vaccination strategies that target the generation of humoral immunity offer limited heterosubtypic protection; T cells offer cross-strain protection and the promise of universal immunity against IAV. Local tissue immunity plays a key role in pathogen clearance and tissue protection, particularly in the form of tissue resident memory T cells (TRM), which are a non-circulating memory T cell subset that have been shown in a variety of tissue sites to be superior mediators of protection compared to circulating memory T cells. At the same time, T cell immunity has been associated with inflammatory processes that may also lead to lung immunopathology. How lung tissue localized T cell immunity mediates its protection during a recall response to IAV challenge is not well understood.
Using the lymphocyte sequestering drug FTY720, we show that primary infection with H3N2 IAV strain X31 provides tissue localized heterosubtypic immunity independently of humoral immunity against an H1N1 PR8 IAV strain. Within the lung resident niche, the recall response drives faster CD4+ and CD8+ T cell expansion compared to a primary infection. This rapid T cell expansion resulted from in situ TRM proliferation that was augmented by the migration of peripheral T cells. By tracking a naïve T cell population specific for the IAV strain used in secondary challenge, we demonstrate that influenza-specific T cells, including those specific for newly introduced antigens, migrate to the lung niche from the local mediastinal lymph node (medLN) where both CD4+ and CD8+ T cells experience enhanced priming and proliferation. We further show that primary infection fortifies the medLN with persistently increased numbers of T cells as well as both CD103+ and CD103- conventional dendritic cells (cDCs) that are transcriptionally similar to cDCs in an infection naïve mouse. By depleting Zbtb46+ cDCs, we determine that cDC fortification is a crucial mechanism for enhanced T cell priming and expansion in the medLN during a recall response.
We also found that lung localized CD4+ T cell responses exhibit significant immunomodulatory function. Polyclonal lung CD4+ TRM generated by influenza infection as well as lung OT-II TRM exhibit increased production of antiviral inflammatory cytokines in addition to enhanced IL-10 family cytokine production compared to splenic CD4+ effector memory T cells (TEM). During a heterosubtypic challenge, we further observed that lung niche non-TRM CD4+ T cells produce significantly more in situ IL-10 compared to a primary infection, which modulated airway IFN-ɣ and TNF-α production without any depreciation in viral clearance. Immunomodulatory characteristics of a recall response was reflected in lung tissue-wide transcriptional downregulation of innate responses such as type I IFN responses compared to a primary infection. This work demonstrates the dual antiviral and immunomodulatory protective role of enhanced tissue-localized T cell responses during the recall response to IAV challenge.
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Chan, Jennifer. "Pre-existing strain specific neutralising antibodies abrogates the induction of interferon type I and cytotoxic T cell responses to subsequent homotypic influenza A virus challenge." Thesis, 2013. http://hdl.handle.net/2440/90751.
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Current inactivated influenza vaccines target the generation of influenza-specific antibodies to provide homotypic protection. However, little is known about the effects of annual vaccinations on the immune response during a subsequent influenza A virus infection. Here, we investigated the effect of pre-existing influenza-specific neutralising antibodies on innate and adaptive immunity during secondary infections.
We report that the presence of pre-existing antibodies abrogates the induction of interferon type I (IFN-I) responses and cytotoxic T cell responses during subsequent influenza A virus infection. Wild-type mice were vaccinated intravenously with gamma-irradiated A/PR8 [H1N1] (γ-A/PR8) and challenged 3 weeks later with live A/PR8, and splenocytes were analysed 24 hours later for IFN-I mediated lymphocyte activation using fluorescent activated cell sorting. Our data clearly show absence of partial systemic lymphocyte activation and IFN-I responses in vaccinated mice. Furthermore, co-administration of A/PR8-specific sera and live A/PR8 virus abrogated the ability of live virus to induce partial lymphocyte activation, IFN-I responses as well as cytotoxic T cell responses. To test the clinical relevance of this observation, mice were mock or vaccinated with γ-A/PR8 and infected 3 weeks later with sub-lethal dose of A/PR8. These animals were then challenged 3 weeks later with lethal dose of A/PC [H3N2]. Our data clearly illustrate the effect of pre-existing antibodies on the ability of sub-lethal infection to generate cytotoxic T cell mediated heterosubtypic protection. I also investigated whether IFN-I responses are required for the generation of cytotoxic T cell responses in the presence of neutralising immune sera. My data show that addition of exogenous Poly I:C to A/PR8 virus pre-treated with A/PR8-specific sera did not rescue the induction of cytotoxic T cell responses. Thus, the presence of neutralising antibodies abrogates the induction of IFN-I and cytotoxic T cell responses during homotypic influenza A virus re-infection.Thesis (M.Phil.) -- University of Adelaide, School of Molecular and Biomedical Science, 2013
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Tung, Yen-Chun, and 董彥君. "The effect of E2 glycoprotein vaccination on the distribution of classical swine fever virus antigen after challenge." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/90276610208842381943.
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Lin, Wei-Ting, and 林煒庭. "Attenuated Salmonella enterica serovar Typhimurium expressing DEN-2 NS1 antigen effectively immunizes mice against dengue virus challenge." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/36633676190162953355.
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碩士國防醫學院
微生物及免疫學研究所
92
The objects of this study contains three fold; firstly, to investigate the expression of NS1 protein of Dengue virus via a Caf1 cherapone/usher secretion pathway; secondly, to study the immune response to NS1:Caf1 fusion protein delivered by attenuated Salmonella typhimurium SL1344 strain in a murine infection model; and thirdly, to determine whether protein priming-oral Salmonella boosting immunization against the Dengue NS1 antigen could induce a protective immune response against Dengue virus challenge. Our results demonstrated that NS1 antigen of Dengue virus could be successfully expressed as a NS1:Caf1 fusion protein and secreted on the surface of the cells in both E.coli and Salmonella via Caf1 secretion system. In particular overexpression of Caf1A resulted in higher level of soluble NS1:Caf1 protein present in the extracellular compartment as compared to that of the non-induced one. This results indicated that Caf1A may also play a critical role in promotion of the assembly and folding of sCaf1 (signal sequence) targeting polypeptide, such as NS1:Caf1 fusion protein. However, mice administrated with single oral dose of S.typhimurium SL1344/pLT105 was not appeared to be eliciting high level of specific anti-NS1 serum titer. But it was significantly increased by 2-3 fold in the anti-NS1 serum titer when co-dosed with amphotericin B suggesting that amphotericin B was likely to be as a potential adjuvant for Salmonella oral vaccine. Furthermore, co-dosing with AmB and S. typhimurium SL1344/pLT105 mice obtained 70% protection against the Dengue virus challenge in comparison with that of 30 % for S.typhimurium SL1344/pLT105 alone. In addition mice immunized with a parenteral NS1 protein vaccine followed by an oral boosting with S. typhimurium SL1344/pLT105 could obtain better protection than by single immunized regime. Taken together the results clearly demonstrated that Dengue NS1 protein antigen could be expressed as a soluble NS1:Caf1 fusion protein and highly displayed on the cell surface in E. coli and Salmonella. Single oral dose with S. typhimurium SL1344/pLT105 could confer partial protection for mice against lethal dose of Dengue virus challenge. Protein priming-oral Salmonella boosting regime could provide an effective way to increasely elicit protective immune response to against Dengue virus challenge. As an adjuvant amphotericin B is able to augment the immune response for Salmonella oral vaccine.
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Lin, Chien-Hung, and 林建宏. "Protectivity of Variant F Genotype Newcastle Disease Virus Inactivated Vaccine against Newly Isolated Viscerotropic Velogenic NDV Challenge." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/42232628781985652922.
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碩士國立屏東科技大學
獸醫學系所
100
Newcastle disease virus (NDV) is a highly virulent pathogens of poultrys. Since the recently high occurrence of the Newcastle disease (ND) have been found correlated with the antigenic variation of the causative velogenic viscerotropic NDV (VVNDV)，9 isolates of NDV isolated during 2008 to 2010 were chosed to run of its pathogenicity evaluation in term of mean death time (MDT) in chicken embryos, cross hemagglutination- inhibition (HI) test for figuring out of its R-value, phylogenetic analysis of its F gene nucleotide sequence and comparison of the F gene deduced amino acid sequence with the corresponding strains retrieved from GenBank. All the 9 isolates were found with MDT of 44-52 hour and classified as the VVNDV，phylogenetically grouping asⅦe4 basis on the F gene nucleotide analysis and all characterized with 5 deduced amino acids changes (L23-F、I26-T、T29-A、S30-N和T90-A)on its F protein. Seven inactivated ND oil emulsion vaccines (OEV) with monovalent or bivalent antigens prepared from 5 variant genotype of NDVs (VII-V158、III-Ishii、II-VH、II- LaSota及III-Sato) were used for immunizing a group of leghorn males preimmunized with B1 and LaSota live ND vaccines. All the chickens were bled at 3 and 6 weeks post vaccination of the ND inactivated OEV. Each group was then divided into 2 subgroups. Each subgroup was then orally challenged with the Sato strain or a mixture of 4 isolates of genotype VII NDVs (NDV-VII-4). The protectivity of each subgroup against Sato strain challenge was all over 80%. Meanwhile only the subgroup immunized with the vaccine containing the V158 antigen provided 100% protectivity against NDV-VII-4 challenge. In order to figuring out the quanitity of antigen for putting in the inactivated ND vaccine, 4 isolates (V158,V165,V223 and V301) of genotype VII NDV antigen prepared from chicken embryo allantoic fluid or cell culture were used for preparing 16 aluminum hydroxide type vaccines at 4 levels (4X, 2X, 1X and 0.5X) of antigen for immunizing a group of leghorn males preimmunized with B1 and LaSota live ND vaccines. All the chickens were bled at 3 weeks post vaccination of the ND inactivated vaccine. Each group was then orally challenged with the NDV-VII-4. At 7 days post challenges, all the conrol group chickens were died out. Meanwhile all the inactivated NDV immunized provided 100% protection except the groups of the chickens immunized with the inactivated vaccine containing the V165 antigen origeiated from chicken embryo. The above 4 strains of VII genotype NDV is good for using as ND inactivated vaccine producing seed.
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Drennan, John D. "DNA vaccines encoding the glycoprotein genes of spring viremia of carp virus, snakehead rhabdovirus, or infectious hematopoietic necrosis virus induce protective immunity in rainbow trout (Oncorhynchus mykiss) against an infectious hematopoietic necrosis virus lethal challenge." Thesis, 1998. http://hdl.handle.net/1957/33623.
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Recent advances in DNA vaccine technology has brought about a promising
strategy for the control of viruses that contain surface membrane glycoproteins. This type
of vaccine involves the intramuscular injection of a bacterial plasmid containing a gene
encoding a viral protein. The strategy uses eukaryotic processing of the protein as would
naturally occur during a viral infection. In this study, plasmid DNA encoding the
glycoproteins of infectious hematopoietic necrosis virus (pcDNA3-IHNV-g), snakehead
rhabdovirus (pcDNA3-SHRV-g), or spring viremia of carp virus (pcDNA3-SVCV-g) was
injected into the skeletal muscle of rainbow trout fry. At 30 days post-vaccination, fish
were challenged with IHNV. Protection against IHNV was observed among all DNA
vaccinated groups. Fish injected with plasmid pcDNA3-IHNV-g, pcDNA3-SHRV-g, or
pcDNA3-SVCV-g had relative survival rates of 93.2%, 98.3% and 94.9%, respectively.
The mechanisms for the viral mediated resistance induced by these glycoprotein based DNA vaccines is unknown. A parallel study conducted by Dr. Carol Kim on the production of Mx proteins in these fish indicates that the observed protection might be a consequence of the stimulation of interferon.Graduation date: 1999
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Miao, Congrong. "Cytokine messenger RNA expression in calves vaccinated intranasally with modified-live bovine respiratory syncytial virus (BRSV) prior to BRSV challenge." 2003. http://purl.galileo.usg.edu/uga%5Fetd/miao%5Fcongrong%5F200305%5Fms.
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Silva, Tânia Rodrigues da. "Integrity monitoring of reverse osmosis membranes: Potential for naturally present viruses to verify virus removal comparing to MS2 bacteriophages." Master's thesis, 2017. http://hdl.handle.net/10362/27769.
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Reverse osmosis membrane filtration is becoming an interesting solution since it is in principle an effective barrier against pathogenic microorganisms in water. Although having the ability to treat many water sources and provide safe drinking water, viruses are the smallest pathogenic microorganisms and therefore the most challenging to verify their removal in membrane filtration. For a reverse osmosis filtration system to be secure to public health, a trustful membrane integrity monitoring method is crucial to detect damages.
The use of MS2 phages is currently the most used challenge test to validate virus removal in RO membranes. Although it has numerous advantages such as their similarity in size and morphology to enteric human viruses, it still has the drawbacks of being spiked in the feed water and not being feasible in full-scale plants.
This dissertation focused on assessing the potential of a new challenge test that uses naturally occurring viruses in surface water to validate virus removal in RO membranes. This is a promising method since it discards the need of introducing components into the feed water thus being applicable to drinking water plants.
Using a reverse osmosis pilot scale, experiments were performed using intact and damaged spiral wound membranes to assess the potential of using natural present viruses in surface water for validating virus removal in comparison with the performance of the already known good method – MS2 bacteriophages.
The findings in this research demonstrate that both MS2 and naturally present viruses challenge tests achieved above 7 log removal values in the presence of intact membranes. Compromised membranes with induced pinholes achieved different log removal values according to the severity of the inflicted damages indicating sensitivity to detect impairments by both challenge tests. Greater loss of membrane integrity was observed when four pinholes with 1-mm diameter were inflicted on the membrane, followed by one 4- and one 1-mm diameter.
Based on the consistency of the achieved log removal values between the two challenge tests, these results therefore demonstrate the potential of using natural present viruses to verify virus removal, particularly the suitability of the natural virus used in this research to be an adequate virus removal indicator.
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Ferreira, Hugo Miguel Lambuça. "Overcome challenges in influenza virus-like particles downstream process." Master's thesis, 2017. http://hdl.handle.net/10362/24817.
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The development of new vaccines for influenza virus introduced a new generation of vaccines using virus-like particles (VLPs). The lack of genetic material, possibility of production on cell lines and presence of antigens with immunogenicity are the main advantages over the traditional vaccines. The development of a cost-effective downstream process while maintaining the high purity, potency and quality of VLPs is a challenge. In this thesis, several purification steps – clarification, concentration, chromatography, polishing and sterile filtration – were studied to develop a new downstream proves for influenza VLPs.
In clarification step, a strategy using D0HC followed by Opticap XL SHC filters presented the best result. For concentration step, the cassette with cut-off of 300 kDa presented a higher yield on hemagglutinin recovery and the lowest process time. For chromatography step, the membrane Sartobind Q and the resin HiTrap Q HP were evaluated, concluding that resin HiTrap presented higher dynamic binding capacity and better resolution on elution. For polishing step, size-exclusion chromatography and multimodal chromatography operate in flow-through mode were compared. The last presented higher recovery yield on hemagglutinin and it was select due to the non-limitation for scale-up. Different materials were analysed for the final sterile filtration.
A proof of concept run was performed were the optimized conditions and best devices were evaluated. In the end of process, it was obtained influenza VLPs with concentration and quality enough to advance for animal in vivo studies and for clinical phase I.
Additionally, a new tool – magnetic sulphated cellulose particles – was evaluated with the goal to obtain purified and concentrated samples to use in characterization techniques.
Overall, this thesis contributes to introduce a new tool and a novel cost-effective downstream purification process with high purity, potency and quality for the next generation of influenza vaccines - VLPs.O desenvolvimento de novas vacinas para o vírus de influenza introduziu uma nova geração de vacinas utilizando partículas semelhantes a vírus (VLPs). A ausência de material genético, possibilidade de produção em linhas celulares e presença de antigénios com imunogenicidade são as principais vantagens em relação às vacinas tradicionais. O desenvolvimento de um processo de purificação de baixo custo mantendo a elevada pureza, potencia e qualidade das VLPs é um desafio. Nesta tese, alguns passos de purificação – clarificação, concentração, cromatografia, polimento e filtração estéril final – foram estudados para desenvolver um novo processo de purificação de VLPs de influenza. Na clarificação, a estratégia usando os filtros D0HC seguido do Opticap XL SHC apresentaram os melhores resultados. Na concentração, a cassete com cut-off de 300 kDa apresentou um maior rendimento na recuperação de hemaglutinina e o mais baixo tempo de operação. Na cromatografia, a membrana Sartobind Q e a resina HiTrap Q HP foram avaliadas, concluindo-se que a resina apresenta maior capacidade de ligação dinâmica e maior resolução na eluição. No polimento, a cromatografia de exclusão molecular e a cromatografia multimodal, operada em flow-through comparadas. Esta última apresentou valores superiores de recuperação de hemaglutinina sendo escolhida por não conter limitações no escalamento. Diferentes materiais foram analisados na filtração estéril final. Na realização da corrida de prova de conceito as condições ótimas e os melhores materiais foram estudadas. No final do processo, obteve-se VLPs de influenza na concentração e qualidade suficiente para avançar para estudos em animais in vivo e para fase clínica I. Adicionalmente, uma nova ferramenta – partículas magnéticas de celulose sulfatada – foram estudadas com objetivo de obter VLPs purificadas e concentradas para utilização em técnicas de caracterização. Em geral, esta tese contribuiu para introduzir uma nova ferramenta e um novo processo de purificação mais económico com elevada pureza, potência e qualidade, para a nova geração de vacinas - VLPs.
iBET
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Huang, Yi-Ting, and 黃怡婷. "Japanese Encephalitis Virus Replicon-Based Vaccine Expressing Enterovirus-71 Epitope Confers Dual Protection from Lethal Challenges." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/13245472952057346803.
Full textAbstract:
博士國防醫學院
生命科學研究所
103
To construct a safer recombinant flavivirus vaccine, we exploited a Japanese encephalitis virus (JEV) replicon-based platform to generate single-round infectious particles (SRIPs) that expressed heterologous neutralizing epitope SP70 derived from enterovirus-71 (EV71). Such pseudo-infectious virus particles, named SRIP-SP70, although they are not genuine viable viruses, closely mimic live virus infection to elicit immune responses within one round of a viral life cycle. We found that, besides gaining full protection to thwart JEV lethal challenge, female outbred ICR mice, when were immunized with SRIP-SP70 by prime-boost protocol, could not only induce SP70-specific and IgG2a predominant antibodies but also provide their newborns certain degree of protection against EV71 lethal challenge. Our results, therefore, exemplify that this vaccination strategy could indeed confer an immunized host a dual protective immunity against subsequent lethal challenges from either JEV or EV71.
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Segoale, Nare Okney. "Challenges faced by mothers with human immunodeficiency virus positive children in Pietersburg Hospital, Limpopo Province South Africa." Thesis, 2020. http://hdl.handle.net/10386/3435.
Full textAbstract:
Thesis(M.A.(Nursing)) -- University of Limpopo, 2020The purpose of the study was to identify and explore the challenges faced by mothers with HIV positive children and who were admitted to Pietersburg Hospital, Limpopo Province, South Africa, during the period of study. A qualitative research methodology was used in the study based on exploratory and descriptive designs. The population for the study included all mothers of children who are HIV positive and had been admitted to the Paediatric Ward of Pietersburg Hospital, Limpopo Province, during the period of study. Non-probability purposive sampling was used to draw a sample of twelve (12) HIV positive participants from the research population. Data was collected from twelve participants through the use of semi-structured in-depth interviews, guided by an interview schedule. Fields notes were captured for non-verbal communication and a voice recorder was used to capture all the audio record of the interview sessions. Ethical clearance for the study was obtained from Turfloop Research Ethics Committee (TREC); and permission to collect data at the Pietersburg Hospital was obtained from the Limpopo Department of Health as well as the hospital’s Chief Executive Officer and from the Operational Manager of the Paediatric Ward. The findings from the study indicated that mothers of HIV positive children experienced numerous psychosocial and economic challenges on a daily basis. These challenges include accepting their own and their children’s HIV positive status; and also disclosing the status to their children. They also had to deal with opportunistic infections that the HIV positive children are more susceptible to, as well as challenges of ensuring that their children did not default on the medication schedules. Poverty and the lack of finances to pay for the various special needs of HIV positive children were also other key challenges experienced by the mothers. In light of these findings the study recommends the need for HIV/AIDS education, support from families and significant others as well as from the government. The study also recommends that well-coordinated and integrated inter-departmental intervention programmes are required to help mothers cope with their challenges.
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Runyan, Chase. "Evaluation of Immune Response and Performance in Steers of Known Genetic Background Vaccinated and Challenged with Bovine Viral Diarrhea Virus." 2010. http://hdl.handle.net/1969.1/ETD-TAMU-2010-12-8966.
Full textAbstract:
This research was directed at investigating the variation in immune response of cattle when administered a known challenge from Bovine Viral Diarrhea Virus (BVDV) following different Bovine Respiratory Disease (BRD) vaccine treatments. Cattle were assigned vaccine treatments with sire and cow family was stratified across treatments to assess the role genetic differences may impact immune function. The same BVDV strain and challenge technique were used in two trials (2008 and 2009) in Angus-sired yearling steers. Data from these two years were analyzed separately because the cattle were managed and fed differently.
Blood antibody Immunoglobulin-G (IgG) titers for IBR, BVD Type 1 and BVD Type 2 were higher for cattle in the Killed vaccine group than the MLV or NON vaccinated groups (P < 0.05) in both years. In the 2008 study, average daily gain (ADG) was higher for cattle from the Killed vaccine group (P < 0.05) for the 28 d following BVDV challenge, but no cattle were classified as morbid based on rectal temperature. In the 2009 study, differences in rectal temperatures were observed, and a total of 35 of 93 having over 40.0 degrees C (28 in the first 14 d following challenge). Cattle in the MLV vaccine group had lower overall mean temperatures, with no animals having rectal temperatures over 40 degrees C 14 d following viral challenges. Differences in rectal temperature were also observed due to sire. Differences in feed intake also occurred due to treatment, day, treatment × day interaction, and maternal-grandsire. The MLV vaccine group maintained more constant levels of intake as compared to Killed and NON vaccinated cattle at days 5 to 12. Although large differences in titers following BVDV challenge were observed, the relationships of this immune response with animal health and performance appears very complex.
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Skhosana, Thabang Johannes. "A pentecostal response to the challenges of HIV/AIDS in Tumahole." Diss., 2000. http://hdl.handle.net/10500/16052.
Full textAbstract:
This dissertation is a challenge to the Pentecostal churches, particularly, the Apostolic Faith Mission Church in Tumahole, to take an action in meeting the challenges posed by HIV/AIDS. This disease, HIV/AIDS, is the latest enemy to human life that the nations are faced with. In the newspapers like Sowetan, there is an article almost daily about HIV and AIDS. In this dissertation, I have tried to show shocking figures of how this disease is spreading in Africa. The seriousness of the disease, unlike other diseases, is its in curability. The secular organisations are far ahead of the churches in as far as the relevant programmes on
combating HIV/AIDS are concerned. Despite these massive programmes, the disease is spreading like the wild fire. Deducing from this background, it is no longer the question of whether the Pentecostal churches have any role to play, but what specific role should the
church play in this challenge. In this challenging times, many people look at the church as one of the most important institute that would play a positive role in bringing hope to the hopeless.Christian Spirituality, Church History and Missiology
M. Th. (Missiology (Urban Ministry))
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Ebrahim, Sumayyah. "The scope and spectrum of challenges presented to the general surgeon by patients affected with the human immunodeficiency virus (HIV) : a review." Thesis, 2012. http://hdl.handle.net/10413/9376.
Full textAbstract:
Background: Surgical disease related to HIV is scantily documented with a paucity of data
detailing the manifestations of HIV in surgery especially in resource-poor, high prevalence
settings such as in South Africa. This review provides an update on the topical issues
surrounding HIV and surgery.
Objectives: The objective of the study was to determine the incidence, pathogenesis, clinical
presentation, aspects of diagnosis and management of: HIV- associated salivary gland disease
in particular parotid gland enlargement; Kaposi’s sarcoma (KS) and lower limb
lymphoedema; AIDS- related abdominal malignancies due to KS and lymphoma; Acalculous
cholecystitis and HIV- cholangiopathy and HIV- associated vasculopathy.
Methods: A collective review of the literature was performed and data sourced from a search
of relevant electronic medical databases for literature from the period 2000 to the present
date. Studies under each section were selected based on inclusion and exclusion criteria.
Content analysis was used to analyse data.
Results: The HIV pandemic has resulted in an increased frequency of benign
lymphoepithelial cysts making it the commonest cause of parotidomegaly in most surgical
practices. KS should be considered in the differential diagnosis of a patient with chronic
lymphoedema. Lymphoedema may be present without cutaneous lesions, making clinical
diagnosis of KS difficult. The gastrointestinal tract is the commonest site of extra- cutaneous
KS. Surgical management of the lymphoma patient is restricted nowadays to determining the
diagnosis and in some cases to evaluate disease stage. Highly active antiretroviral therapy
(HAART) is an important part of the management of biliary tract conditions in addition to
relevant surgical procedures. HIV- vasculopathy represents a distinct clinico- pathological
entity characterized by a vasculitis with probable immune- mediated or direct HIV- related
injury to the vessel wall.
Conclusion: The rising incidence of HIV in South Africa and other developing countries has
been associated with new and unusual disease manifestations requiring surgical management
for diagnostic, palliative or curative intent. It is crucial that surgeons remain abreast of new
developments related to the challenging spectrum of HIV and its protean manifestations.Thesis (M.Med.)-University of KwaZulu-Natal, Durban, 2012.
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Jaiswal, Jessica Lynn. "A qualitative study of urban people of color living with human immunodeficiency virus: challenges related to retention in care, antiretroviral therapy acceptance, and “conspiracy beliefs”." Thesis, 2017. https://doi.org/10.7916/D8GF106X.
Full textAbstract:
Background: Despite advances in HIV medication, many people living with HIV (PLWH) do not link to care upon diagnosis, do not remain engaged if linked, and do not achieve viral suppression through consistent ART adherence. Not achieving viral suppression is associated with low CD4-cell counts, preventable hospitalizations, frequent emergency room usage, risk of developing a drug resistance, and excess morbidity and mortality. Despite extensive literature that explores barriers to care, these disparities remain, particularly among racial, ethnic and sexual minority groups. Mistrust of health care systems and/or providers is thought to provide a partial explanation for why racial and ethnic minority groups are less likely to access outpatient HIV care. One form of health-related mistrust, referred to as “conspiracy beliefs” in the literature and in popular culture, is particularly associated with racial and ethnic minority people. HIV-related “conspiracy beliefs” can include the ideas that the government created HIV to target specific minority groups, that antiretroviral medication is used to experiment on vulnerable groups, or that a cure is being withheld or delayed by pharmaceutical companies and/or the government. Although many studies have assessed the prevalence of such beliefs, little is known about the possible relationship between endorsing these ideas and engagement from HIV care/ART adherence among PLWH. Moreover, the extant literature has provided equivocal findings that point to the need for further research on the relationship between these beliefs and managing one’s HIV.
Methods: Over the course of one year, 27 semi-structured, in-depth interviews were conducted with low income PLWH of color living in the NYC area that are currently, or were recently, disengaged from outpatient HIV medical care. Additionally, a brief questionnaire was administered to obtain demographic and engagement/medication adherence data to describe the sample of participants.
Findings: This analysis revealed the variation, texture and diversity related to people’s beliefs about the origin and treatment of HIV. Beliefs about the pharmaceutical industry and the government highlighted both the racism and classism experienced by low income who belong to racial and ethnic minority groups. Notably, HIV care providers did not appear to be perceived as part of the government-pharmaceutical power complex. This suggests that while many people may endorse these types of ideas, endorsement does not necessarily directly impact engagement in care. However, endorsing positive beliefs about the efficacy of ART, and the belief that HIV can be a chronic disease if treated consistently, helped participants remain adherent or desire to re-commit to taking it consistently. Participants also appreciated, and desired, providers that engaged in patient-centered medicine.
Recommendations:
It may be that public health does not necessarily need to endeavor to dislodge origin or pharmaceutical/cure-related beliefs; rather, interventions can focus on building trust between health care providers and populations that have been experienced both historically and ongoing marginalization. Participants’ emphasis on wanting to manage their ART-related challenges with their providers suggests that HIV providers have an instrumental role in not only lowering viral loads and achieving viral suppression, but also helping their patients feel agentic and able to manage their HIV. Implementing patient-centered medicine will also engender trust, thereby helping patients internalize the belief that consistent engagement and ART adherence makes HIV a chronic, manageable illness.
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Mabusela, Mmalesiba Dorothea. "An investigation of the challenges and coping mechanisms of home-based caregivers for patients living with HIV in Mamelodi." Diss., 2010. http://hdl.handle.net/10500/4750.
Full textAbstract:
HIV/AIDS is a global challenge and its impact is evident. This places a burden on hospitals and health professionals. To ease this burden there are home-based care programmes which, through home-based caregivers, provide patients living with HIV/AIDS with physical and palliative care.
However, these HBCGs face various challenges such as poverty, discrimination and stigma when caring for PALHIV, and their own emotional strain, which becomes burdensome without sufficient support from the home-based care centre.
The qualitative study undertaken investigates the challenges and coping mechanisms of the HBCGs. Thirteen research participants were drawn from a centre in Mamelodi.
Data was gathered through interviews and observations, categorised into themes and analysed. Major findings revealed that social challenges faced by HBCGs include poverty, stigmatisation and discrimination. Emotions experienced by HBCGs include guilt, anger, hopelessness, but they have spiritual reliance through prayer as one of their coping mechanisms.Sociology
M.A. (Social Behaviour Studies in HIV/AIDS)
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Zitha, Sipho Siphiwosethu. "An investigation into the role and challenges faced by AIDS Councils in addressing HIV and AIDS in their communities: the case of the Ehlanzeni AIDS Council." Diss., 2014. http://hdl.handle.net/10500/20023.
Full textAbstract:
Text in EnglishThe purpose of this study was to investigate the role and challenges of AIDS Councils in addressing HIV and AIDS in their communities with regard to community mobilization and advocacy within the broader advocacy function of the South African National AIDS Council (SANAC) and within the framework of the HIV & AIDS and STI Strategic plan for South Africa 2007-2011(NSP). A qualitative research design was applied. Individual face to face interviews were conducted with the respondents who were purposively sampled across the five local municipalities comprising Ehlanzeni District Municipality. Similar studies conducted previously suggest that many AIDS Councils stakeholders and members had a limited understanding of their role, and encountered more challenges in addressing HIV and AIDS in their communities. This study revealed that stakeholders and members seem to have steadily progressed in understanding their role as well as in weathering the various challenges they are confronted with within the AIDS councils. Be that as it may, there still exists some gaps between what is envisaged in both the NSPs (NSP 2000-2005 and NSP 2006-2011) and the current situation in many LACs. Many questions still need to be answered if South Africans are prepared to triumph over the AIDS pandemic.
Sociology
M.A. (Sociology (Social Behaviour Studies in HIV and AIDS))
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Shoopala, Naemi Ndahambemlela. "Effective prevention of mother-to-child transmission of HIV at Oshakati District Health Centre in the Republic of Namibia." Thesis, 2012. http://hdl.handle.net/10500/6082.
Full textAbstract:
The aim of this study was to assess the extent on how effective was the prevention of mother-to-child transmission of Human Immunodeficiency Virus (HIV) infection at Oshakati District Health Centre. Explanatory survey was used to conduct the research. A total of 160 nurses experienced in prevention of mother-to-child transmission and women who attended antenatal care and post natal care services participated in the study. Respondents expressed unsatisfactory with the promoting involvement of male partners, high quality voluntary counselling and testing services, couple counselling and testing, integration of Highly Active Antiretroviral Therapy services, administration of short course of Zidovudine to pregnant mothers and the provision of antiretroviral drugs to infants. Therefore, promoting involvement of male partners, couple counselling and testing, administration of short course of Zidovudine to pregnant mothers and educating women about exclusive breastfeeding prior to delivery are some of recommendations for effective prevention of mother-to-child transmission of HIV infections.Health Studies
(M.A. (Public Health))
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Shoopala, Naemi Ndahambelela. "Effective prevention of mother-to-child transmission of HIV at Oshakati District Health Centre in the Republic of Namibia." Thesis, 2012. http://hdl.handle.net/10500/6082.
Full textAbstract:
The aim of this study was to assess the extent on how effective was the prevention of mother-to-child transmission of Human Immunodeficiency Virus (HIV) infection at Oshakati District Health Centre. Explanatory survey was used to conduct the research. A total of 160 nurses experienced in prevention of mother-to-child transmission and women who attended antenatal care and post natal care services participated in the study. Respondents expressed unsatisfactory with the promoting involvement of male partners, high quality voluntary counselling and testing services, couple counselling and testing, integration of Highly Active Antiretroviral Therapy services, administration of short course of Zidovudine to pregnant mothers and the provision of antiretroviral drugs to infants. Therefore, promoting involvement of male partners, couple counselling and testing, administration of short course of Zidovudine to pregnant mothers and educating women about exclusive breastfeeding prior to delivery are some of recommendations for effective prevention of mother-to-child transmission of HIV infections.Health Studies
M.A. (Public Health)