Dissertations / Theses on the topic 'Hepatitis viruses Transmission'
To see the other types of publications on this topic, follow the link: Hepatitis viruses Transmission.
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Hepatitis viruses Transmission.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Cossaboom, Caitlin Marie. "Discovery of Novel Strains of Animal Hepatitis E Viruses in the United States: Antigenic and Genetic Characterization, Cross-Species Infection, and Public Health Implications." Diss., Virginia Tech, 2015. http://hdl.handle.net/10919/77998.
Full textAbstract:
Hepatitis E virus (HEV) is an important human pathogen, with pigs and likely other animal species serving as natural reservoirs. There are currently four recognized HEV genotypes that infect humans within the genus Hepevirus of the family Hepeviridae. Genotypes 1 and 2 are human viruses that are associated with waterborne and fecal-oral transmission in developing countries, while genotypes 3 and 4 have been identified in humans and other animal species and are zoonotic and endemic in both industrialized and developing countries.
In my dissertation research, we identified the first strain of HEV from rabbits in the United States. We subsequently determined the complete genome sequence of the virus. Phylogenetic analyses of the full-length sequence indicated that U.S. rabbit HEV is a distant member of the zoonotic genotype 3, thus raising a potential concern for zoonotic infection. In order to investigate the cross-species potential of rabbit HEV, we then determined its antigenic cross-reactivity with other animal strains of HEV. Additionally, we demonstrated that the novel rabbit HEV could cross species barriers and infect pigs under experimental conditions.
Finally, we attempted to determine the risk factors and sources of foodborne HEV infection in the United States. We detected HEV for the first time from non-liver pork commercial products in the United States and demonstrated consumption of undercooked meat a risk factor for HEV infection. HEV sequences of genotype 3 origin were detected from pork products purchased from grocery stores in Southwest Virginia. Approximately 6.3% (21/335) of university students tested seropositive for HEV antibodies and, importantly, those with a history of consuming undercooked meats were 13 times more likely to be seropositive. These results further underscore the importance of cooking pork thoroughly and using proper hygiene when preparing meals.Ph. D.
2
Kavaka, Evniki. "Medical students acting as health educators :the influence on adolescents' knowledge about HIV/Hepatitis B transmission, as well as attitudes, beliefs and intentions towards condom use." Thesis, University of the Western Cape, 2006. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_1268_1194348373.
Full textAbstract:
The aim of this quasi-experimental study was to examine the impact of a health education intervention on knowledge about HIV/Hepatitis B transmission, attitudes, beliefs and intentions towards condom use. Research has shown tht small group discussion, single sex groups, age proximity of health educators, and HIV prevention integrated in the broader sexual health context, increased the effectiveness of health education with regard to safer sexual practices.
3
Ngui, Siew Lin. "Molecular analysis of hepatitis B virus transmission events." Thesis, University College London (University of London), 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.299915.
Full text
4
Passini, Sione Souza Santos. "Prevalência de infecção pelo vírus da hepatite C (VHC)em gestantes e transmissão materno-infantil." Centro de Pesquisas Gonçalo Moniz, 2012. https://www.arca.fiocruz.br/handle/icict/7151.
Full textAbstract:
Submitted by Ana Maria Fiscina Sampaio (fiscina@bahia.fiocruz.br) on 2013-10-15T16:15:07Z
No. of bitstreams: 1
Sione Passini Prevalência de infecção... 2013.pdf: 2410664 bytes, checksum: 9fd8b1765a81738455f4e2fc95fd769a (MD5)Made available in DSpace on 2013-10-15T16:15:07Z (GMT). No. of bitstreams: 1 Sione Passini Prevalência de infecção... 2013.pdf: 2410664 bytes, checksum: 9fd8b1765a81738455f4e2fc95fd769a (MD5) Previous issue date: 2012
Fundação Oswaldo Cruz. Centro de Pesquisas Gonçalo Moniz. Salvador, BA, Brasil
A transmissão materno-infantil (TMI) do vírus da hepatite C (VHC) ocorre em 4%-13% das gestações quando a mãe é infectada, e poucos estudos de prevalência foram realizados em gestantes no Brasil. O objetivo desta pesquisa foi determinar a prevalência de infecção e fatores associados à presença de infecção pelo VHC em gestantes, e determinar a taxa de TMI do VHC. O estudo foi realizado em Salvador, no período entre Maio de 2009 e Abril de 2011, na Maternidade Referência Professor José Maria Magalhães Netto. Todas as voluntárias que assinaram ao TCLE, tiveram seus prontuários revisados e tiveram amostra de soro coletada para a realização do teste rápido anti-VHC (Bioeasy), ELISA 3ª geração (Artech), e detecção do VHC-RNA Qualitativo e Quantitativo (AMPLICOR HCV TESTE, ROCHE versão 2.0). Em uma subamostra de gestantes selecionada aleatoriamente, realizouse entrevista para analisar fatores sócio-demográficos e de exposição ao VHC não disponíveis nos prontuários. A análise estatística descritiva e de associação foram realizadas utilizando o programa EPI Info 3.5.3 (CDC, Atlanta, GE, EUA). Foram incluídas no estudo 3.049 gestantes, sendo que 8 (0,26%; IC 95%: 0,12%-0,50%)foram soropositivos para o anti-VHC pelo ELISA e 6 (0,20%; IC 95%: 0,08%-0,41%) confirmaram viremia. Todos os VHC genotipados pertenceram ao genótipo 1, 1a ou 1b. Os principais fatores associados à infecção materna pelo VHC foram uso de drogas, tatuagem, e infecção por HIV (p < 0,05). Das 6 gestantes com HCV positivo, 2 (33,3%; IC 95%: 6,0%-73,8%) transmitiram o HCV para seus filhos. Em um dos casos de TMI, a mãe relatou ter feito uso de drogas injetáveis e inaláveis durante a gestação, possuía tatuagem e era portadora do HIV sob tratamento antiretroviral. O recém-nascido (RN) nasceu com idade gestacional (IG) de 38 semanas através de parto cesariano eletivo. No outro caso, a mãe relatou uso de drogas injetáveis e inaláveis, possuía piercing e tatuagem, mas não foi portadora de HIV. O RN nasceu com IG de 39 semanas, através de parto normal, com tempo de ruptura da bolsa de 15 horas. Concluímos que a prevalência de infecção pelo VHC entre gestantes é baixa quando comparada à da população em geral na mesma localidade, sendo associado a uso de drogas e tatuagem. A taxa de TMI do VHC encontrada foi maior do que o esperado. Assim, estudos mais amplos serão necessários.
The mother-to-child transmission (MTCT) of hepatitis C virus (HCV) occurs in 4%- 13% of pregnancies when the mothers are infected and very few studies were conducted to determine the HCV prevalence in pregnant women in Brazil. The aim of this work was to determine the prevalence and associated factors of HCV infection in pregnant women, and the rate of the MTCT of HCV. It was conducted in Salvador, between March 2009 and April 2011, at the maternity hospital Prof. José Maria Magalhães Netto. All volunteers signed to informed consent, their medical records were reviewed and serum samples were collect for screening anti-HCV antibody by a rapid anti-HCV testing (Bioeasy), ELISA 3rd generation (Artech), and HCV-RNA qualitative and quantitative detection (AMPLICOR HCV TEST, ROCHE version 2.0). In a randomly selected pregnant women subsample, interviews were made to evaluate socio-demographic and exposure factors for HCV, not available in the records. The descriptive and association statistical analysis were performed using Epi Info 3.5.3 (CDC, Atlanta, GE, USA). The study included 3.049 pregnant women, 8 (0.26%; 95% CI: 0.12%-0.50%) were anti-HCV positive by ELISA and 6 (0.20%; 95% CI: 0.08%-0.41%) confirmed viremia. All genotypes HCV belonged to genotype 1, 1a or 1b. Injection and inhaled drug use, tattoo and piercing were the most important associated factors for the mother infection. Out of the 6 HCV infected mothers, 2 (33.3%; 95% CI: 6.0%-73.8%) transmitted HCV to their newborns. In one of the cases of MTCT, the mother reported to injection and inhaled drug user during pregnancy, had tattoo and was HIV carrier held under antiretroviral therapy. The newborn was born at gestational age (GA) 38 weeks by elective cesarean section. In the other case, the mother was also injection and inhaled drug user, had piercing and tattooing. Her newborn was born at GA 39 weeks by normal delivery, and time of rupture of membranes was estimated to be 15 hours. We conclude that the prevalence of HCV infection among pregnant women was lower than the prevalence in the general population in the same locality, been associated to drug use and tattoo. The rate of MTCT of HCV was higher than expected. Thus, larger studies are required.
5
Pembrey, Lucy Jane. "Mother-to-child transmission of hepatitis C virus : a European epidemiological collaboration." Thesis, University College London (University of London), 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.429494.
Full text
6
Crossan, Claire Louise. "Hepatitis E virus : its impact and route of transmission in developed countries." Thesis, Glasgow Caledonian University, 2016. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.726758.
Full text
7
Protopapas, Stella A. B. A. "Mother to Child Transmission of Hepatitis C Virus in the Greater Cincinnati Area." University of Cincinnati / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ucin154392119827537.
Full text
8
BORTUZZO, THIERRY. "Etude de la transmission verticale du virus de l'hepatite c." Clermont-Ferrand 1, 1993. http://www.theses.fr/1993CLF1MS23.
Full text
9
Feagins, Alicia R. "Foodborne Transmission and Molecular Mechanism of Cross-species Infection of Hepatitis E Virus (HEV)." Diss., Virginia Tech, 2010. http://hdl.handle.net/10919/77266.
Full textAbstract:
Hepatitis E virus (HEV), the causative agent of hepatitis E, is an emerging virus of global distribution. At least four distinct genotypes of HEV exist worldwide: genotype 1 and 2 HEV strains are responsible for waterborne epidemics; genotype 3 and 4 HEV strains are responsible for sporadic occurrences of acute hepatitis E. Genotype 3 and 4 HEVs are zoonotic and have a more expanded host range than genotypes 1 and 2 which are restricted to humans. Genotype 3 and 4 HEV isolates obtained from animal tissues are genetically very similar, or identical in some cases, to human HEV recovered from hepatitis E patients. The objectives of this dissertation research were to assess the zoonotic foodborne transmission of HEV and elucidate the viral determinants of HEV host range. To determine the risk of HEV foodborne transmission, 127 packages of commercial pig liver were tested for HEV RNA. Eleven percent of them were positive for HEV RNA and the contaminating virus remained infectious. We also demonstrated that medium-to-rare cooking condition (56°C) does not completely inactivate HEV, although frying and boiling of the contaminated livers inactivated the virus. To reduce the risk of foodborne HEV transmission, commercial pig livers must be thoroughly cooked for consumption. To determine the host range of genotype 4 HEVs, pigs were inoculated with a genotype 4 human HEV. All pigs developed an active HEV infection indicating that genotype 4 human HEVs can cross species barriers and infect pigs. To identify viral determinant(s) of species tropism, ORF2 alone or in combination with its adjacent 5′ junction region (JR) and 3′ non-coding region (NCR), were swapped between genotypes 1 and 4, 3 and 4, and 1 and 3 to produce 5 chimeric viruses. Chimeric viruses containing ORF2 or JR+ORF2+3' NCR from genotype 4 human HEV in the backbone of genotype 3 swine HEV were viable in vitro and infectious in vivo. Chimeric viruses containing the JR+ORF2+3'NCR of genotypes 3 or 4 HEV in the backbone of genotype 1 human HEV were viable in vitro but non-infectious in pigs, suggesting that ORF1 may also be important for host range.Ph. D.
10
David, Xavier Richard. "Transmission familiale du virus de l'hépatite C : à propos de 213 individus représentant 88 familles." Montpellier 1, 1991. http://www.theses.fr/1991MON11190.
Full text
11
Maponga, Tongai Gibson. "An investigation of hepatitis B virus in antenatal women tested for human immunodeficiency virus, in the Western Cape Province of South Africa." Stellenbosch : Stellenbosch University, 2012. http://hdl.handle.net/10019.1/20416.
Full textAbstract:
Thesis (MScMedSc)--Stellenbosch University, 2012.ENGLISH ABSTRACT: Hepatitis B virus (HBV) immunisation protocols in much of Africa are based on data from the pre-human immunodeficiency virus (pre-HIV) era that indicated that HBV transmission occurs predominantly horizontally between siblings and play-mates rather than vertically from mother to child. The immunosuppression associated with HIV infection however may release HBV from immune control resulting in higher HBV viral loads, which may increase the risk of perinatal mother to child transmission of HBV. The aim of this study was to determine the prevalence and characteristics of chronic HBV infection in HIV-infected pregnant women compared to HIV-uninfected pregnant women in the Western Cape province of South Africa. Ethical approval was obtained to conduct a retrospective, matched case-control, unlinked anonymous study using residual plasma samples from the 9355 pregnant women included in the Western Cape's 2008 National HIV and Syphilis Antenatal Survey. Samples were tested for HBsAg on the AxSYM (Abbott, Chicago, IL) and confirmed by neutralization. Confirmed HBsAg-positive samples were tested for HBeAg, anti-HBe and anti-HD (Diasorin, Saluggia, Italy) and had HBV viral load and genotyping done. In addition, HBsAg-negative samples were tested for anti-HBc. Samples from 1549 HIV-infected pregnant women were included and matched to the same number of samples from age- and race-matched HIV-uninfected women. Median age of 26 years, parity and education were similar in the two groups. The prevalence of HBsAg was 3.4% for the HIV-infected group and 2.9% for the HIV-uninfected group. HBV DNA loads of greater than 104 IU/ml were detected in 32.1% of HBsAg-positive, HIV/HBV co-infected women, and in 14.3% HBsAg positive, HBV mono-infected women. Among the HIV-infected group 18.9% of HBsAg-positive were HBeAg positive, with a median viral load of 7.93 log10 IU/ml; whilst 15.5% HIV-uninfected women were positive for HBeAg with a median viral load of 6.07 log10 IU/ml. Genotype A was seen in 92.6% of the isolates while 7.4% of the isolates were genotype D. Serum total anti-HBc antibodies that are a marker of past infection were detected in 42.2% of HIV-infected and in 24.1% of HIV-uninfected women that were negative for HBsAg. No positive sample for anti-HD was seen among all HBsAg-positive samples. This data indicates that there is increased exposure to HBV in HIV-infected pregnant women than in HIV-uninfected women and that a greater proportion of HIV-infected pregnant women compared to HBV mono-infected pregnant women may be at increased risk of transmitting HBV to their infants. Further studies are needed to determine the rate of vertical transmission of HBV in the HIV era.
AFRIKAANSE OPSOMMING: Hepatitis B virus (HBV) immunisasie protokolle vir meeste dele van Afrika is gebaseer op data versamel in die era voor MIV. Die data dui aan dat HBV oordrag hoofsaaklik deur horisontale transmissie tussen broers, susters en speelmaats eerder as vertikale transmissie van moeder na kind plaasvind. Die onderdrukking van die immuunstelsel as gevolg van MIV infeksie kan egter lei tot 'n verhoogde risiko van perinatale HBV oordrag van moeder na kind. Die doel van hierdie studie was om die voorkoms en karakter van chroniese HBV infeksie in MIV-positiewe swanger vroue te vergelyk met die van MIV-negatiewe swanger vroue. Etiese goedkeuring is verkry om 'n retrospektiewe, deursnee-, ongekoppelde anonieme studie uit te voer wat gebruik maak van oorblywende plasma monsters van 9355 swanger vroue wat ingesluit is in die Wes-Kaap 2008 Nasionale MIV en Sifilis Voorgeboortelike Opname. Die monsters was getoets vir HBsAg antiliggame (AxSYM, Abbott, Chicago, IL) en bevestig deur neutralisasie toetse. Positiewe monsters was getoets vir HBeAg en anti-HBe (Diasorin, Saluggia, Italië). HBV viruslading en genotipering was ook op HBsAg positiewe monsters gedoen. Die HBsAg negatiewe monsters was getoets vir die teenwoordigheid van anti-HBc. Monsters van 1549 MIV-positiewe swanger vroue was ingesluit in die studie. Dieselfde aantal monsters van MIV-negatiewe vroue, met ooreenstemende ouderdom en etnisiteit, was ingesluit as kontroles. Die gemiddelde ouderdom van albei groepe was 26 jaar. Pariteit en opvoeding was dieselfde in albei groepe. Die voorkomssyfer van HbsAg was 3.4% in die MIV-positiewe groep en 2.8% in die MIV-negatiewe groep. HBV DNS ladings van meer as 104 IU/ml was waargeneem in 32.1% van die MIV-mede-geinfekteerde vroue en in 14.3% van die MIV-negatiewe groep. In die MIV-positiewe groep was 18.9% vroue HBeAg positief, met 'n gemiddelde virale lading van 7.93 log10 IU/ml, terwyl 15.5% MIV-negatiewe vroue positief was vir HBeAg met 'n gemiddelde virale lading van 6.07 log10 IU/ml. In ons studie was 92.6% van die monsters genotipe A en 7.4% genotipe D. Toatale anti-HBc antiliggame, 'n merker van vorige infeksie, was gevind in 42.2% van MIV-mede-geïnfekteerde vroue en 24.1% van MIV-negatiewe vroue wat negatief was vir HBsAg antiliggame. Data van ons studie dui op 'n verhoogde risiko vir vertikale HBV transmissie van MIV-positiewe moeders na hul babas. Verdere studies word benodig om vas te stel of vertikale transmissie van HBV van MIV-positiewe vroue na hul babas plaasvind.
Wellcome Trust
Poliomyelitis Research Foundation
12
Xiao, Fei. "Hepatitis C virus entry and cell-cell transmission : implication for viral life cycle and antiviral treatment." Thesis, Strasbourg, 2014. http://www.theses.fr/2014STRAJ124/document.
Full textAbstract:
Le virus de l'hépatite C (HCV) représente un problème de santé publique à l'échelle mondiale. Les thérapies actuelles ne permettent pas de guérir tous les patients infectés par le HCV et certains antiviraux ont des effets secondaires importants. Dans la première partie de ma thèse, nous avons identifié des combinaisons d'antiviraux à action directe (DAA) et d'inhibiteurs d'entrée caractérisés par un effet synergique dans la prévention et le traitement du HCV dans des modèles de culture cellulaire et les souris uPA-SCID avec un foie chimérique. Ceci représente une nouvelle stratégies de lutte contre l'infection par le HCV. Dans la seconde partie de ma thèse, nous avons démontré que le mode de transmission du HCV de cellule à cellule est la voie de transmission dominante dans les modèles de culture cellulaire. De plus, les virus résistant aux DAA se propagent efficacement grâce à la transmission de cellule à cellule. L'inhibition de la transmission de cellule à cellule en utilisant des inhibiteurs d'entrée est un moyen efficace pour empêcher l'émergence de virus résistant aux DAA et pour potentialiser l'efficacité antivirale des DAA pour éradiquer l'infection par le HCVHepatitis C virus (HCV) poses a threat to global health with infecting about 170 million people. Current therapies cannot cure all the patients infected with HCV and have obvious side effects. In the first part of my thesis, we uncovered combinations of direct-acting antivirals (DAAs) and entry inhibitors caracterized by a synergistic effect in prevention and treatment of HCV infection using HCV cell culture models and human liver chimeric uPA-SCID mice, thereby providing a new strategy to control HCV infection. In the second part of my thesis, we demonstrated that HCV cell-cell transmission is the dominant transmission route in cell culture models and that DAA-resistant HCV spread efficiently through cell-cell transmission to develop viral resistance. Blocking cell-cell transmission using entry inhibitors allows to prevent the emergence of DAA-resistant virus and potentiates the antiviral efficacy of DAAs to clear HCV infection. In summary, we provide novel strategies to enhance antiviral efficacy by combining entry inhibitors and DAAs and to prevent viral resistance by blocking viral cell-cell transmission
13
LE, POGAM SOPHIE. "Typage du virus de l'hepatite c : epidemiologie moleculaire de la transmission." Tours, 1998. http://www.theses.fr/1998TOUR3303.
Full text
14
Girard, Anne. "Recherche d'une transmission hétérosexuelle du virus de l'hépatite C : à propos de 26 couples." Bordeaux 2, 1990. http://www.theses.fr/1990BOR25037.
Full text
15
Bradshaw, Daniel Mark. "Defining risk factors and mechanisms of permucosal transmission of HCV amongst HIV-infected men who have sex with men." Thesis, University of Cambridge, 2016. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.709469.
Full text
16
Berto, Alessandra. "Hepatitis E virus : identification and evaluation of the potential for zoonotic transmission in the pork food chain." Thesis, University of Surrey, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.576103.
Full textAbstract:
Hepatitis E is an acute hepatitis in humans, first recognised in 1980 and caused by hepatitis E virus (HEV). The principal mode of spread of HEV is faecal-oral from contaminated water supplies, almost exclusively in developing regions. Accumulating evidence indicates that HEV transmission may be zoonotic in developed regions from swine and perhaps other animal species serving as reservoirs for the virus. The exact transmission routes are unclear, largely because HEV is extremely difficult to propagate in vitro, but retail pig products have been shown to contain HEV RNA. This PhD project was part of the EU FP7 project VITAL (Integrated Monitoring and Control of Food borne Viruses in European Food Supply Chains). The main aim of this PhD project was to investigate the presence and residual infectivity of HEV in the pork food chain. This helped to assess the potential importance of the pig and its products in zoonotic transmission of HEV. A cell culture system for HEV was further optimised for HEV detection in food samples. A productive HEV infection was established in 3D cell culture (Alexander hepatoma PLC/PRF/S) that was permissive for HEV replication. Furthermore, a trial to compare the efficiency of 3D, 2D and 3D transferred to 2D cells culture systems was performed indicating that replication in the 3D cell culture system was the most efficient. In addition, these studies showed that cells grown in 3D and then transferred to 2D for infection were able to support HEV replication. Further refinements such as heat, UV light and sodium hypochlorite inactivation studies were performed. These approaches should enable an assessment of the significance 1 of the pork food chain in transmission of HEV and facilitate the development of control measures. Within the VITAL project standard methods were developed to have common viral detection and extraction methods between all laboratories, and ring trials were organized between 15 EU laboratories to assess the efficacy of the Standard Operating Procedures (SOPs) developed. Since all the laboratories involved were able to detect the viruses with the common SOPs the ring trial was considered successful and the second step of the project began, involving the screening by real time RT-PCR for HEV throughout the pork food chain. One of 40 pig livers and 6 of 63 pork sausages were found to be HEV positive. Virus viability was tested using the 3D cell culture system but no evidence of viral replication was detected. A mathematical model' suggested that the Circulation of HEV in six European countries is endemic. In addition, HEV prevalence in pig's faeces was investigated showing that pigs close to the slaughter age can still be HEV positive. In conclusion, the work carried out in this PhD projected contributed to our understanding of HEV replication in-vitro and provided useful information on the prevalence of HEV in the pork food chain in the UK. In addition, progress was made with possible inactivation methods and control strategies. 2
17
Gonçales, Neiva Sellan Lopes. "Hepatite C em doadores de sangue : diagnostico pela reação de transição reversa e reação em cadeia da polimerase (RT-PCR) e sua correlação com os testes imunoenzimatico (EIA) e imunoblot recombinante (RIBA)." [s.n.], 1997. http://repositorio.unicamp.br/jspui/handle/REPOSIP/309322.
Full textAbstract:
Orientador: Fernando Ferreira CostaTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas
Made available in DSpace on 2018-07-23T00:34:31Z (GMT). No. of bitstreams: 1 Goncales_NeivaSellanLopes_D.pdf: 4155293 bytes, checksum: 36e63708c0b3ae4e06c3c227420d5165 (MD5) Previous issue date: 1997
Resumo: No Brasil, previne-se a transmissão por transfusão sangüínea do vírus da hepatite C com a triagem dos doadores de sangue realizada por meio da pesquisa do anti VHC pelo método de EIA e dosagem dos níveis séricos da ALT. A especificidade da triagem do anti-VHC por EIA, em populações de baixa soroprevalência, tem sido questionada. Assim, para avaliar-se a eficácia desta triagem, pesquisou-se a presença, com o uso da RT-PCR, do RNA viral em amostras de doadores de sangue, procurando-se, também, estabelecer as associações entre os resultados desta reação e os testes de EIA e RIBA. Procurou-se, ainda, detectar marcadores teciduais para o VHC, com a utilização de Um anticorpo monoclonal específico, pela técnica de imuno-histoquímica eimunofluorescência em cortes de tecido hepático parafinado. Foram estudadas 196 amostras de soro, coletadas no período de janeiro de 1994 a dezembro de 1995. Entre estas, 178 foram selecionadas de uma população de doadores de sangue voluntários do Centro de Hematologia e Hemoterapia da UNICAMP e, 18 de pacientes atendidos no Ambulatório do Grupo de Estudos das Hepatites da Disciplina de Doenças Infecciosas e Parasitárias da Faculdade de Ciências Médicas desta Universidade. Dos 178, 147 (82,6%) apresentaram-se à triagem com resultados repetidamente reagentes para o anti- VHC e não-reagentes para o HBsBAg, anti-HBc, anti-lllV1/2, anti-HTL VI/IT, além de serem negativos para marcadores da Doença de Chagas e Sífilis. Os 31 (17,4%) restantes eram repetidamente negativos para todos os marcadores sorológicos acima citados e apresentavam níveis de AL T nonnais (grupo controle). As 18 amostras de pacientes estudadas eram negativas para a pesquisa do anti-HIV1/2 e foram investigadas sorologicamente para os diferentes tipos de hepatites, de acordo com a avaliação clínica. Os 14 T doadores foram subagrupados de acordo com os critérios baseados nas leituras das densidades ópticas das amostras em relação ao "cutoff' (DO/C) do teste de ElA para o anti-VHC e o nível de ALT. A seqüência do RNA do VHC foi detectada pela RT- "nested" PCR, utilizando-se "primers" da região 5' não-transcrita, que é a mais conservada do genoma viral. O ensaio de "imunnoblot" recombinante (RIBA-2) também foi realizado nas mesmas amostras. No subgrupo considerado ElA fortemente reagente, 95,4% apresentaram aumento nos níveis séricos de ALT, enquanto que no sub-grupo ElA fTacamente reagente apenas, 47,1% tiveram níveis de ALT elevados. No subgrupo ElA fortemente reagente houve 96,9% de co-positividade com o teste de RIBA. A realização deste mostrou-se necessária para definir a condição sorológica dos indivíduos EIA fracamente reagente, uma vez que apenas 53% confirmaram a positividade inicial, permanecendo 23,5% como indeterminados e 23,5% como negativos. Observou-se uma relação direta entre a reatividade contra o antígeno do core do VHC (c22.3) e a presença de partículas virais no soro. Entre os RIBA indeterminados (reativos apenas para o c22.3), 87,5% apresentaram positividade para a RT-PCR. Em 91,5% dos indivíduos com EIA fortemente reagente, detectou-se o RNA do VHC pela RT-PCR contra apenas 17,6% no subgrupo EIA fracamente reagente. A concordância entre os resultados positivos de RIBA e RT-PCR foi de 85,9%. Por estes achados conclui-se que os dois testes devam ser aplicados isolada ou seqüencialmente para confirmar a infecção pelo VHC, principalmente em populações com baixas prevalências da mesma, como é o caso dos doadores de sangue. Entre os indivíduos com hepatite crônica histologicamente confirmada não se encontrou nenhum caso com resultado de RIBA negativo. Em 92,3% deste grupo observou-se positividade para o RNA do VHC pela RT-PCR. Os testes de ElA e RIBA utilizados neste estudo apresentaram alta sensibilidade e especificidade, considerando-se como população positiva aqueles indivíduos com diagnósticos histopatológicos de hepatites crônicas, com positividade para aRT-PCR. Assim, conclui-se que a triagem sorológica, em nosso serviço, para prevenir a transmissão do VHC, na transfusão de sangue, mostrou-se eficiente e capaz de selecionar os doadores infectados, principalmente se for usada como critério a relação DO/C no teste de ELA. A utilização do anticorpo monoclonal específico, TORDJI-22, em tecido hepático parafinado pela técnica de imuno-histoquímica ou imunofluorescência não permitiu evidenciar a presença do VHC neste tecido em nossa casuística. Os testes de triagem sorológica (ELA e RIBA) associados ao método de RTPCR e ao diagnóstico anátomo-patológico propiciarão ao clínico manipular melhor as interrelações e as variáveis envolvidas na infecção pelo vírus C
Abstract: The transmission of hepatitis C virus in Brazil is currently monitored either by an anti-HCV enzyme-immunoassay (ElA) or by the deterrnination of ALT serum levels. However specificity of the anti-HCV ElA in low seroprevalence populations has been questioned. ln order to evaluate the efficiency of this test, blood samples were screened for the presence of viral RNA using RT -PCR and the results then compared with those of the ElA and recombinant protein immunoblot assay (RIBA) tests. lmmunohistochemistry and immunofluorescence of paraffin embedded hepatic tissue were employed to detect HCV tis sue markers using a specific monoclonal antibody. A total of 178 serum samples obtained ITom voluntary blood donors at the Hematology and Hemotherapy Center (UNICAMP) and 18 samples from patients who were attended by the Hepatitis Group of the lnfectious and Parasitic Diseases Unit were studied between January, 1994 and December 1995. One hundred and forty-seven samples (82.6%) consistently reacted with antiHCV antibody but not with HBsBAg, anti-HBc, anti-HIV1/2, or anti-HTL VIlII antibodies; these samples were negative for syphilis and the Chagas' disease. The remaining 31 samples (17.4%) were consistently negative for all of the above serological markers and showed normal ALT levels (control group). The 18 samples obtained from hepatitis patients were negative for anti-HIV1/2 antibody. The 147 positive donors were divided into subgroups based on the outoff (C) for the optical density readings (OD) of the anti-HCV ElA test and on their ALT levels. The RNA sequence of HCV was detected by RT-nested PCR using primers from the 5' non-transcribted region which is the most conserved of the viral genome. A RIBA-2 was also performed on these samples. The majority (95.4%) of the samples that gave a strongly reactive EIA result also showed an increase in the serum AL T levels while only 47.1 % of the weakly reactive EIA subgroup had elevated serum AL T levels. The co-positivity of the EIA test with the RIBA test in the strongly reactive EIA subgroup was 96.9%.The RIBA test proved to be important and necessary in defining the serological status of the weakly reactive EIA subgroup; thus, 53% of the samples were EIA positivite, 23.5% were negative and in 23.5% was not determined. There was a direct positive relationship between the reactivity to the HCV core (c22.3) and the presence of serum viral particles. Among indeterminate RIBA results (reactive only to c22.3) 87.5% were positive by RT-PCR. HCV-RNA was detected in 91.5% of the strongly reactive EIA samples compared to only 17.6% observed in the weakly reactive EIA group. There was a high level of agreement 85.9% between the RIBA results and RT-PCR test. Based on this findings these two tests may be used either separately or sequentially to conflrm an HCV infection, particularly in populations whese the prevalence ofthis infection is low (as in the case ofblood donors). There were no RIBA negative results in individual with histologically conflrmed chronic hepatitis. Using RTPCR, RNA-HCV was detected in 92.3% of this group. Our results showed a high sensitivity and specificity for EIA and RIBA tests in individuaIs with a histopathological diagnosis ofchronic hepatitis and who were positive by the RT-PCR test. In conclusion, the serological screening as performed in our laboratory for HCV transmission in blood transfusions is efficient and capable of detecting infected donors, particularly if the OD/C report of the EIA test is used as a criterion. The specific monoclonal antibody TORDll-22 was unable to detect the presence of HCV in the hepatic tissue evaluated by immunohistochemical br immunofluorescent techniques. The EIA and RIBA tests, association with RT-PCR method and anatomicopathological diagnosis, may be useful in evaluating the relationships and parameters involved HCV infections
Doutorado
Anatomia Patologica
Doutor em Ciências Médicas
18
Sloan, Richard David. "Studies into the transmission of hepatitis B virus that mutate following therapy with nucleoside analogues and the potential for such transmission to be serologically undetectable." Thesis, University College London (University of London), 2008. http://discovery.ucl.ac.uk/1445917/.
Full textAbstract:
The hepatitis B virus (HBV) genome is organised so that the open reading frame encoding the polymerase overlaps that encoding hepatitis B virus surface antigen (HBsAg). Previous studies showed that acquisition of lamivudine resistance-associated mutations in pal result in a decreased affinity of HBsAg for its antibody (anti-HBs). It was sought to characterize epitope changes in the major immunogenic domain of HBsAg, the "a" determinant, that result from lamivudine, adefovir and entecavir resistance mutations. Recombinant (r) HBsAg was produced by transfecting Chinese Hamster Ovary cells (CHO) with a plasmid containing the surface open reading frame modified by site-directed mutagenesis to mimic mutations selected in the overlapping pol/S gene during antiviral therapy. Wild type and mutant rHBsAgs expressed from these constructs were assayed using a series of EIAs each employing a monoclonal antibody which binds distinct epitopes in the first and second loop of the "a" determinant. Specific combinations of mutations led to variable loss of immunoreactivity of the epitopes of the "a" domain, despite some mutations not being located in that domain. Some combinations of mutations led to restoration of reactivity of epitopes which were abrogated by single mutations. Thus mutations associated with antiviral resistance have the potential to affect serological reactivity through concomitant amino acid substitutions in HBsAg. These observations may have implications for the clinical treatment of chronic HBV, diagnostics and vaccine programmes. The molecular epidemiology of antiviral-associated mutants in England and Wales between 1997-2001 was also assessed. HBV DNA from the 1st 600 bases of the HBsAg-coding gene was amplified from 163 patients with acute hepatitis B and subjected to phylogenetic analysis. None of the patients were found infected with HBV mutants that would have arisen following the development of antiviral resistance or with vaccine-escape mutants. Transmission by pre-existing iatrogenic HBV mutants was therefore rare or did not occur.
19
Chotun, Bibi Nafiisah. "The prevalence of Hepatitis B virus infection in an HIV-exposed paediatric cohort from the Western Cape, South Africa." Stellenbosch : Stellenbosch University, 2012. http://hdl.handle.net/10019.1/71771.
Full textAbstract:
Thesis (MScMedSc))--Stellenbosch University, 2012.Includes bibliography
ENGLISH ABSTRACT: Despite the availability of Hepatitis B virus (HBV) vaccination for over three decades, this infection remains a major public health problem. Whilst the WHO recommends giving a birth dose of the vaccine, in South Africa, routine infant HBV vaccination commences at six weeks of age. This schedule is based on data from the pre-HIV era which showed transmission occurred via the horizontal, rather than the vertical route. In the era of HIV however, maternal HIV co-infection may release HBV from immune control, resulting in higher HBV loads and increasing the risk of vertical transmission. The aim of this study was to determine the prevalence and character of HBV infection in HIV-exposed infected and uninfected infants. Residual plasma samples from routine HIV nucleic acid testing of 1000 HIV-exposed infants aged between 0 and 18 months from the Western Cape were tested. Samples were tested for HBsAg by ELISA (Murex HBsAg Version 3) and confirmed by neutralisation. HBV DNA was quantified using an in-house real-time PCR assay. Infants with HBsAg positive samples were followed up and a blood sample was collected from mother and child. Those HBsAg positive samples were tested for HBeAg/antiHBe (Diasorin) and HBsAg negative samples were tested for antiHBs. HBV DNA was quantified. The surface gene was sequenced and the HBV genotype determined by phylogenetic analysis using HepSEQ (www.hepseq.org.uk). Whole genome sequencing was also performed. Of 1000 samples tested, four samples were positive for HBsAg and/or HBV DNA, indicating a prevalence of HBV transmission of 0.4%. At follow-up, two of three infected infants were positive for HBsAg, with HBV viral loads of greater than 108 IU/ml. The third infant was found to have cleared his infection and the fourth child was lost to follow up. These infected infants had all received HBV vaccination. All four mothers were HBeAg positive. Sequencing analysis showed the HBV strains from the two infants and four mothers belonged to subgenotype A1. The two mother-child paired sequences were identical. The data from this study shows that vertical transmission of HBV infection in HIV-exposed infants from the Western Cape is occurring, despite vaccination. Data from the Western Cape, showing an HBV prevalence of 3.4% in HIV-infected pregnant women, and those presented here suggest a vertical transmission rate of HBV of 12%. This is despite the widespread use of tenofovir and lamivudine in HIV-infected women with low CD4 counts. This study provides data supporting calls to bring HBV vaccination closer to the time of birth. Further work is urgently needed to confirm these findings and to determine the rates of transmission in HIV-unexposed infants.
AFRIKAANSE OPSOMMING: Ten spyte van die beskikbaarheid van die Hepatitis B virus (HBV) inenting vir meer as drie dekades, hierdie infeksie bly 'n groot openbare gesondheid probleem. Terwyl die WGO aan beveel dat'n geboorte dosis van die entstof, in Suid-Afrika, roetine baba HBV inenting op die ouderdom van ses weke gegee word. Hierdie skedule is gebaseer op data van die pre-MIV era wat getoon het dat die oordrag plaasgevind het via die horisontale, eerder as die vertikale roete. In die era van MIV egter, moeder MIV ko-infeksie kan HBV vrylaat van immuun beheer, wat lei in hoër HBV vlakke en die verhoging van die risiko van vertikale oordrag. Die doel van hierdie studie was om die voorkoms en karakter van die HBV infeksie in MIV-besmette en onbesmette babas te bepaal. Residuele plasma monsters van roetine-MIV-nukleïensuur toetse van 'n 1000 MIV-blootgestelde babas tussen die ouderdomme van 0 en 18 maande van die Wes-Kaap was getoets. Monsters was getoets vir HBsAg deur ELISA (Murex HBsAg Version 3) en bevestig deur neutralisering. HBV DNA is gekwantifiseer deur gebruik te maak van 'n in-huis real-time PCR assay. Babas met HBsAg positiewe monsters was opgevolg en 'n bloedmonster is versamel van moeder en kind. Die HBsAg positiewe monsters was getoets vir HBeAg/antiHBe (Diasorin) en HBsAg negatiewe monsters was getoets vir antiHBs. HBV DNA was gekwantifiseer. Die oppervlak gene volgorde en genotipes was bepaal deur filogenetiese analise met behulp van HepSEQ (www.hepseq.org.uk). Die hele genoom-volgordebepaling was ook uitgevoer. Van die 1000 monsters wat getoets was, was vier monsters positief vir HBsAg en of HBV DNA, dit dui op 'n voorkoms van HBV oordrag van 0.4%. By op volg, twee van die drie besmette babas was positief vir HBsAg, met HBV virale vlakke van groter as 108 IE/ml. Die derde baba was gevind dat sy infeksie opgeklaar het en die vierde kind was verlore as gevolg van op volg. Hierdie besmette babas het almal HBV inenting ontvang. Al vier moeders was HBeAg positief. Volgordebepaling analise het getoon die HBV stamme van die twee babas en vier moeders behoort aan subgenotype A1. Die twee moeder-kind gepaarde rye was homoloë. Die data van hierdie studie toon dat die vertikale oordrag van HBV infeksie in MIV-blootgestelde babas van die Wes-Kaap vind plaas, ten spyte van inenting. Data van die Wes-Kaap, wat 'n HBV voorkoms van 3.4% in MIV-besmette swanger vroue, en dié wat hier aangebied is dui op 'n vertikale oordrag koers van 12% van die HBV. Dit is ten spyte van die wydverspreide gebruik van tenofovir en lamivudine in MIV-geïnfekteerde vroue met 'n lae CD4-telling. Hierdie studie bied data wat ondersteunende oproepe van HBV inenting nader aan die tyd van die geboorte bring. Verdere werk is dringend nodig om die bevindinge te bevestig en die pryse van die oordrag in MIV-blootgestelde babas te bepaal.
National Health Laboratory Service Research Trust
Poliomyelitis Research Foundation (PRF)
Harry Crossley Foundation
Stellenbosch University
20
Schlosser, Josephine [Verfasser]. "Transmission and pathogenesis of hepatitis E virus infection in European wild boar and domestic pigs, and the establishment of a small animal model for hepatitis E / Josephine Schlosser." Hannover : Bibliothek der Tierärztlichen Hochschule Hannover, 2015. http://d-nb.info/1073931005/34.
Full text
21
Stone, Jack Elliot. "Analysing the role of incarceration in the transmission and prevention of human immunodeficiency virus and hepatitis C virus amongst people who inject drugs." Thesis, University of Bristol, 2018. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.743044.
Full text
22
Guinoiseau, Thibault. "Etude des propriétés génétiques et fonctionnelles des variants du virus de l'hépatite C lors d'évènements de transmission." Thesis, Tours, 2018. http://www.theses.fr/2018TOUR3301.
Full textAbstract:
Chez un individu infecté, le VHC circule sous la forme d’une population de variants viraux appelés quasi-espèce. Lors d’un évènement de transmission, certains variants viraux sont préférentiellement transmis et un effondrement de la diversité virale chez l’individu nouvellement infecté est souvent observé. Les propriétés électives de ces variants ainsi que leur rôle dans l’évolution clinique sont méconnus. L’objectif de cette étude est d’identifier si des déterminants moléculaires situés au niveau des glycoprotéines d’enveloppe du VHC sont associés à une plus grande capacité de transmission. Les propriétés fonctionnelles des variants transmis et non transmis seront étudiées, en particulier la sensibilité à la neutralisation autologue. Les échantillons étudiés proviennent de couples mère-enfant infectés chroniquement par le VHC issus de d’un essai clinique réalisé en Thaïlande. La composition des populations virales au sein de 3 paires a été étudiée à l’aide d’une technique d’amplification après dilution limite (SGA) suivie d’un séquençage profond (Illumina). Le variant majoritaire chez la mère était retrouvé majoritaire chez l’enfant pour les paires 1 et 3. Pour 2 paires (2 et 3), une moindre diversité génétique a été observée chez l’enfant par rapport à la mère témoignant d’un goulot d’étranglement génétique lors de la transmission. Après clonage des gènes E1E2, des tests d’infectivité sur cellules hépatocytaires ainsi que des tests de neutralisation par le sérum maternel sont réalisés avec le modèle de rétrovirus pseudotypés (VHCpp). Pour la 1ère paire, le variant majoritaire chez la mère (variant transmis à l’enfant) est infectieux et résistant au sérum autologue. Pour la deuxième paire, le variant minoritaire (transmis) est légèrement résistant à la neutralisation autologue. Un variant majoritaire non transmis apparait sensible à la neutralisation autologue. Des études complémentaires en système de virus réplicatifs issus de la culture cellulaire (VHCcc) sont en cours. Au final, les résultats de cette étude contribuent à comprendre les étapes précoces de l’infection par le VHC, afin de mieux appréhender de futures approches immunoprophylactiques ou vaccinalesIn infected individuals, HCV circulates as a complex mixture of genetically different, but closely related viral variants named quasispecies. In a transmission event, some viral variants are preferentially transmitted. The genetic and functional properties of these variants are still unknown. The aim of our work was to identify molecular determinants of E1E2 associates with a greater capacity of transmission. We also intend to study the functional properties of transmitted and no transmitted variants, as for example sensibility to autologous neutralization. Studied sera samples were obtained from three women and their child infected by the HCV, who were participating in HIV prevention clinical trial for the prevention of perinatal transmission of HIV in Thailand. Quasispecies were studied with single genome amplification (SGA) followed by deep sequencing (Illumina). A decrease in intra-host diversity (genetic bottleneck) was observed in the viral population of child near birth (week 6) compared with that observed in the mother (just before delivery). For 2 pairs, the major variant observed in the mother was the same as the major one identified in the child. Retroviral pseudotypes (HCVpp), bearing each transmitted and non-transmitted envelope glycoproteins were produced. For each one, the level of infectivity on HuH7 cells was measured as well as the neutralizing activity of the autologous sera. For the first pair, the major variant (transmitted) appears resistant to autologous neutralization. For the second pair, the transmitted minor variant appears slightly resistant to autologous neutralization. A non-transmitted major variant is sensitive to autologous neutralization. Complementary studies with HCV derived from cell culture (HCVcc) are in progress We hope that the results of this study may be helpful to better understand early steps of HCV infection, which is of great interest for the development of immunoprophylaxis and vaccine strategies
23
Latthaphasavang, Vatthanaphone. "Suivi prospectif d’une cohorte de femmes enceintes chroniquement infectées par le virus de l’hépatite B (VHB) et de leurs enfants en RDP Laos." Thesis, Lyon, 2018. http://www.theses.fr/2018LYSE1336/document.
Full textAbstract:
Contexte : Environ 257 millions de personnes dans le monde sont infectées de manière chronique par le virus de l'hépatite B (VHB). La transmission mère-enfant représente la majorité des nouveaux porteurs chroniques du VHB, en particulier en Asie. Le VHB peut être transmis in utero, lors de l'accouchement ou pendant la petite enfance voire plus tard. Environ 80 à 90% des nourrissons infectés à la naissance développent une infection chronique par le VHB avec le risque élevé de développer de graves complications, notamment une fibrose du foie, une cirrhose, un carcinome hépatocellulaire jusqu’à un décès lié au foie à l’âge adulte. Nous avons évalué la proportion des enfants immunisés avec succès dans deux grands hôpitaux de Vientiane, en République démocratique populaire lao, où l’immunoglobuline HB (HBIg) n’est pas disponible. Méthodes : Nous avons étudié une cohorte prospective de femmes enceintes infectées par le VHB et de leurs enfants jusqu'à six mois après la naissance de janvier 2015 à mars 2017. Tous les nourrissons ont reçu le vaccin anti-HB à la naissance et six, 10 et 14 semaines après la naissance. Le statut d’infection par le VHB chez l’enfant a été évalué à l’âge de 6 mois. Le séquençage du gène de surface du VHB a été effectué chez des couples mère-enfant infectés. Résultats : Sur 153 mères ayant été dépistées positives pour l'antigène de surface HB (AgHBs), 60 (39%) avaient l'antigène HBe (AgHBe) positif. Les femmes enceintes ayant AgHBe-positif étaient plus jeunes que les femmes ayant d’AgHBe négatif ((âge médian 26 versus 28 ans; p = 0,02). et avaient une charge virale du VHB significativement plus élevée à l'accouchement (médiane 8,0 versus 4,0 log10 UI / mL, p <0,001). Au total, 141 nouveau-nés, dont une paire de jumeaux, sont nés pendant l'étude. Parmi les 112 nouveau-nés pour lesquels l’information concernant le délai entre la naissance et l’heure d’administration du vaccin contre le VHB était disponible, 110 (98%) ont reçu le vaccin dans les 24 heures suivant la naissance. Le délai médian entre la naissance et l'administration du vaccin était de 6 heures (EI 3 à 13), avec 95 (72%) dans les 12 heures suivant la naissance. Un nouveau-né a reçu le vaccin 26 heures après la naissance car le vaccin n'était pas disponible dans la salle d'accouchement et un autre nouveau-né a reçu le vaccin 3 jours après la naissance car, en raison d'une détresse respiratoire sévère à la naissance, le vaccin a été considéré comme contre-indiqué. Parmi les 120 enfants évalués à l'âge de 6 mois, 5 (4%) étaient positifs pour AgHBs et présentaient une charge virale détectable pour le VHB par réaction en chaîne avec une polymérase. Tous sont nés de mères ayant l’AgHBe positif et une charge virale> 8,5 log10 UI / mL. Cependant, seulement quatre enfants (3,3%, IC à 95%, 0,5% à 7,0%) avaient une souche virale étroitement apparentée à celle de leur mère. Des mutations du gène de surface du VHB (G145G/R, G145G/A, M133T, M133I) ont été détectées chez 4 des 5 enfants infectés. Le taux d'anticorps anti-HBs était supérieur à 10 UI / L chez 105 nourrissons (88%) à l'âge de 6 mois. Conclusions : La transmission de la mère à l'enfant s'est produite moins souvent que ce que nous avions prévu en absence de l'utilisation de HBIg. L’ajout d’une prophylaxie par HBIg et / ou antivirale maternelle aurait pu prévenir certaines de ces infections. L'observation du taux d'anticorps anti-HBs non satisfait chez 9% des enfants non infectés à 6 mois souligne la nécessité d'améliorer les procédures d'immunisation universellesBackground: An estimated 257 million people are chronically infected with the hepatitis B virus (HBV) worldwide. Mother-to-child transmission accounts for the majority of new chronic HBV carriers, especially in Asia. HBV can be transmitted in utero, during delivery or during infancy and later. About 80–90% of infants infected at birth will develop a chronic HBV infection, and will have a high risk of developing serious complications including liver fibrosis, cirrhosis, hepatocellular carcinoma (HCC) and liver-related death during adult age. We aimed at assessing the percentage of infants successfully immunized in two major hospitals in Vientiane, Lao People's Democratic Republic (Lao PDR) where HB immune globulin (HBIg) is not available. Methods: We studied a prospective cohort of chronically HBV infected pregnant women and their infants until 6 months post-partum from January 2015 to March 2017. All infants received the HB vaccine at birth and 6, 10 and 14 weeks thereafter, and their HBV status was assessed at 6 months of age. HBV surface gene sequencing was performed in infected mother-infant pairs.Results: Of 153 mothers with HB surface antigen (HBsAg), 60 (39%) had detectable serum HBe antigen (HBeAg). HBeAg positive pregnant women were younger than those negative (median age 26 versus 28 years; p=0.02) and had a significantly higher HBV viral load at delivery (median 8.0 versus 4.0 log10 IU/mL, p <0.001). A total of 141 infants including a pair of twins were included in the study and information at the time of vaccine administration after birth was available for 112 newborns. Of these, 110 (98%) received the HepB-BD within 24 hours after birth. One newborn received the vaccine 26 hours after birth because the vaccine was not available at the delivery room, and another newborn 3 days after birth due to fetal distress, which was erroneously considered to be a vaccine contra-indication. Among the 120 infants assessed at 6 months of age, 5 (4%) were positive for HBsAg and had a detectable HBV viral load by polymerase chain reaction. All were born to mothers with HBeAg and a viral load >8.5 log10 IU/mL. However, only four (3.3%, 95% CI 0.5% to 7.0 %) had a virus strain closely related to their mother’s strain. HBV surface gene mutations were detected in 4 of the 5 infected infants (G145G/R, G145G/A, M133T, M133I). Anti-HBs antibody level was above 10 IU/L in 105 (88%) infants at 6 months of age. Conclusions: Mother-to-child transmission occurred less frequently than expected without the use of HBIg. Adding HBIg and/or maternal antiviral prophylaxis may have prevented some of these infections. The observation of unsatisfactory levels of anti-HBs antibodies in 9% of the uninfected infants at 6 months highlights the need for improvement of the universal immunization procedures
24
Guo, Hailong. "Antigenic epitope composition and protectivity of avian hepatitis E virus (avian HEV) ORF2 protein and vertical transmission of avian HEV." [Ames, Iowa : Iowa State University], 2006.
Find full text
25
Lahlou, Safaâ. "Epidémiologie de l'hépatite C : prévalence dans le groupe hospitalier Lariboisière, F. Widal durant l'année 1998." Paris 5, 1999. http://www.theses.fr/1999PA05P198.
Full text
26
Lima, Maria Patelli Juliani Souza. "Infecção pelo virus da hepatite C entre parturientes : soroprevalencia, analise dos fatores de risco, infectividade e transmissão vertical." [s.n.], 1999. http://repositorio.unicamp.br/jspui/handle/REPOSIP/311835.
Full textAbstract:
Orientador: Rogerio de Jesus PedroTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas
Made available in DSpace on 2018-07-26T09:12:25Z (GMT). No. of bitstreams: 1 Lima_MariaPatelliJulianiSouza_D.pdf: 35315879 bytes, checksum: ecdaf1dfad33a9015ace9a0ecb41173b (MD5) Previous issue date: 1999
Resumo: O estudo realizado no Hospital Universitário da Pontifícia Universidade Católica (PUC) de Campinas entre janeiro de 1994 e julho de 1998 constou de duas partes: a primeira, sobre a soroprevalência do VHC entre parturientes, os fatores de risco envolvidos e o potencial de infectividade entre as mulheres com anti-VHC-EIA positivo, e a segunda, sobre a transmissão vertical do VHC. Na investigação da prevalência dessa infecção, participaram 6.995 mulheres que tiveram o sangue coletado na sala de parto e que responderam a uma entrevista padrão, realizada durante a internação, objetivando a pesquisa de antecedentes epidemiológicos relativos a microorganismos veiculados pelas vias sangüínea e (ou) sexual. Utilizaram-se análises de associação e modelos de regressão múltipla na relação da positividade do RIBA e da presença do RNA-VHC com as variáveis epidemiológicas. A prevalência anti-VHC pelo EIA-3 foi de 1,5% (104/6.995) e de 0,8% após o RIBA-3. Nessa população, obteve-se também a positividade do anti-HIV-EIA de 1,0% e de 0,9% segundo o "Western blot"; a positividade do HBsAg de 0,5% e do anti-HBc de 6,8%; 0,9% de positividade anú-T.pallidum (VDRL e FTA-ABS). Com o teste RT-PCR, pesquisou-se o RNA-VHC em 75 mulheres reativas ao anti- VHC-EIA, e 35 (46,7%) amostras foram positivas. Das 47 amostras com RIBA reagente, 20 (42,6%) apresentaram níveis alterados de ALT, com RNA-VHC em 90% delas, e nas 12 amostras indeterminadas, 2 (16,7%) tinham níveis alterados de ALT, com RNA presente em 50%. No modelo de regressão logística múltipla, as cinco variáveis preditoras da positividade do RIBA, marcador de infecção prévia pelo VHC, foram: uso de bebida alcoólica, transfusão de sangue, pertencer a raça negra, antecedente de DST e anti-HBc positivo. Não foi possível compor esse modelo com a variável uso de drogas injetáveis e VDRL positivo. Repetiu-se a análise multivariada, após controlar as variáveis relativas à transmissão parenteral do VHC, para explorar o potencial da via sexual na transmissão do VHC. Antecedente de DST, presença do anti-HBc, ter ou ter tido parceiro sexual com história de hepatite ou parceiro heterossexual promíscuo foram determinantes da positividade do RIBA. Procurou-se associar os resultados do teste RT-PCR às características do RIBA, aos níveis de ALT, à co-infecção pelo HIV ou VHB e às variáveis epidemiológicas estudadas. Na análise multivariada, as variáveis que estimaram a presença do RNA-VHC foram as interações das bandas cl00-3 - c33c e c22-3 - c33c. Na segunda parte deste estudo, referente à transmissão vertical do VHC, participaram 61 mulheres com anti-VHC-EIA positivo e os respectivos filhos, de 72 partos acompanhados seqüencialmente. Entre o 2° e o 18° mês de vida, coletou-se, no mínimo, uma amostra de sangue. Dessas 72 crianças, 45 tinham mães com RIBA positivo, 13 indeterminado e 14 negativo, sendo 42 delas filhas de mulheres com viremia (39 com RIBA positivo e 03 indeterminado). Dentre os 42 lactentes, incluindo 09 filhos de mães co-infectadas pelo HIV, um apresentou repetidamente o RNA-VHC aos quatro meses de idade, evoluindo com alterações nos níveis de ALT entre o 7º e 11° mês de vida. A positividade da sorologia anti-VHC (EIA e RIBA) desta criança manteve-se até o 18° mês de vida, atendendo ao critério diagnóstico proposto para infecção vertical pelo VHC. A taxa de transmissão foi de 2,4% (01 em 42) e de 3% ao se excluírem as crianças de mulheres co-infectadas pelo HIV (01 em 33). Este estudo demonstrou que a prevalência anti-VHC-EIA entre as mulheres grávidas é superior à dos doadores de sangue do mesmo hospital; que a exposição sexual pode ser um importante fator na disseminação do VHC; e que a transmissão vertical do VHC ocorre, porém, com freqüência baixa
Abstract: This study performed at the University Hospital of the Pontifícia Universidade Católica de Campinas (PUC-Campinas) between January of 1994 and July of 1998 was divided into two parts: the first was about the HCV prevalence among parturients, the risk factors involved in it and the infectivity potential among anti HCV-EIA positive women; the second one was about vertical transmission of the HCV. A total of 6995 women have participated in the HCV prevalence study. The women answered a standard questionnaire during their stay in the hospital and had their blood collected in the obstetric center. These two procedures were performed in order to study the epidemiological history related to pathogens of sexual or blood-borne transmission. Analyses of association and models of multiple regression were utilized in association of the RIBA and HCV RNA positivity with the epidemiological variables. The anti-HCV seroprevalence by EIA-3 was 1.5% (104/6995) and after RIBA-3 was 0.8%. It was obtained in this population anti-HIV-EIA seropositivity of 1.0% and 0.9% according to the Western blot; HBsAg positivity of 0.5% and anti-HBc of 6.8%; and 0.9% of the anti T.pallidum positivity (VDRL and FTA-abs). The HCV RNA was studied, utilizing RT-PCR, in 75 anti-HCV-EIA reactive women, resulting in 35 (46,7%) positive samples. Of the 47 RIBA-reactive samples, 20 (42,6%) showed abnormal alanine aminotransferase (ALT) levels with HCV RNA in 90% of them and, of the 12 eterminate samples, 2 (16,7%) had abnormal ALT levels with HCV RNA in 50% of them. In the model of multiple logistic regression, five independent predictors of RIBA positivity, the marker of previous HCV infection, were: alcohol use, blood transfusion, race (blacks), a history of STD and anti-HBc positivity. It was not possible to build this model with the variables - injectable drug use and positive VDRL . The model of multiple logistic regression was repeated, after controlling for parenteral exposure, in order to explore the potential of the sexual via in HCV transmission. A history of STD, anti-HBc positivity and having or having had promiscuous heterosexual partner or sex partner with a history of hepatitis were determinants of RIBA positivity. The results of RT-PCR test were tested in the association with the characteristics of RIBA results, with ALT levels, with HIV or VHB coinfection, and with the epidemiological variables studied. In the multivariate analysis, RNA HCV was estimated by interactions of the C100 - C33c and of the C22-3 - C33c bands. A total of 61 anti-HCV-EIA-positive women and their respective children, of 72 sequentially assisted deliveries, participated in the second part of this study, which was about HCV vertical transmission. Between the 2nd and the 18th month of age, at least oneblood sample was collected from mother-child. Forty-five out of these children had RIBA-positive mothers; 13 had indeterminate RIBA; and 14 had negative RIBA. Forty-two of them were children of women with viremia: 39 had RIBA-positive mothers and 3 indeterminate. Among the 42 infants there were 09 whose mothers were HIV coinfected. From this total of 42, one presented the RNA-HCV repeatedly at the fourth month of age and he also showed abnormal ALT levels between 7° and 11° month of age. Anti-HCV (EIA and RIB A) positivity of this child was kept until the 18th month of live, according to the proposed diagnostic criteria of vertical transmission. The transmission rate was 2.4% (1 in 42) and 3%, being excluded the children of the HIV-coinfected women (1 in 33). This study has demonstrated that anti-HCV-EIA prevalence was higher in pregnant women than in blood donors of the same hospital; that sexual exposure may be an important factor to the spreading of HCV; and that vertical HCV transmission occurs, but with a low frequency
Doutorado
Clinica Medica
Mestre em Ciências Médicas
27
Viñolas, Tolosa Maria. "Transmissió vertical del virus de l’hepatitis C. Factors de risc, història natural dels nens infectats i evolució a llarg termini." Doctoral thesis, Universitat Autònoma de Barcelona, 2016. http://hdl.handle.net/10803/384220.
Full textAbstract:
Introducció: La TV del VHC succeeix en el 5-15% dels casos i depèn de factors de risc materns, obstètrics i neonatals. Fins el moment existeix poca informació sobre l’evolució dels nens infectats més enllà dels 2 o 3 primers anys de vida. L’objectiu del present estudi es determinar la taxa de TV, els factors de risc i l’evolució a llarg termini dels nens infectats.
Pacients i mètodes: Estudi prospectiu de cohorts de 120 gestants infectades per VHC i els seus fills nascuts a l’Hospital del Mar de Barcelona entre gener de 1994 i desembre de 1996, amb seguiment de 36 mesos per a tots els nens, i de 17-20 anys pels nens infectats. Es registren dades maternes i obstètriques i es realitza ARN-VHC qualitativa i quantitativa a les gestants al part. Es registren les dades neonatals i es fa seguiment dels nens cada 3 mesos fins l’any i mig i cada 6 mesos fins els 3 anys, recollint dades somatomètriques i realitzant proves hepàtiques, anticossos del VHC i ARN-VHC. Els nens infectats són visitats cada 6 mesos, realitzant proves hepàtiques i ARN-VHC i, en cas d’hepatitis crònica, biòpsia hepàtica.
Resultats: L’edat mitjana de les mares fou de 28,2 ± 5,0 anys. La via de contagi del VHC fou majoritàriament per addicció a drogues via parenteral (ADVP), present en 79 mares (65,8%); 22 mares (18,3%) estaven diagnosticades d’hepatitis crònica activa; 50 (41,7%) estaven coinfectades per VIH i 34 (28,8%) van consumir heroïna durant la gestació. Es van infectar per VHC 14 dels nounats, donant una taxa de TV del VHC del 11,7% (IC 95%: 6,0-17,5). Aquesta taxa augmenta al 14% (IC 95%: 6,7-21,3) en mares amb ARN-VHC positiu, al 16,0% (IC 95%: 11,9-20,2) en mares coinfectades per VIH, al 29,2% (IC 95%: 11,0-47,4) en mares amb hepatitis crònica i al 21,8% (IC 95%: 11,0-32,7) en mares amb sociopatia. Els factors de risc de la transmissió vertical estadísticament significatius foren la càrrega viral materna al part, amb taxa de TV del VHC en mares amb càrrega viral >3,9 x105 còpies/ml del 40% (IC 95%: 18,5-61,5), la presència d’hepatitis crònica materna, l’edat materna inferior a 25,0 ± 4,7 anys, la sociopatia materna i la presència de síndrome d’abstinència neonatal. No han estat factors de risc la coinfecció materna per VIH i VHC, l’ADVP, el tipus de part o el sexe del nadó. Cap dels 13 nens nascuts per cesària electiva han estat infectats per TV. El seguiment dels nens infectats mostra bona evolució clínica, sense hepatitis aguda però amb hepatitis crònica de lleu activitat a la biòpsia hepàtica. La taxa de guarició espontània és del 72,7%, essent els factors que hi influeixen la menor càrrega viral materna del VHC al part i el serotipus diferent de l’1. Els nens que guarien espontàniament presentaven menys determinacions positives d’ARN-VHC i menor càrrega viral durant el primer any de vida. Els nens infectats per VHC seguits fins l’edat adulta han precisat seguiment per psiquiatria en els 63% el casos i el 73% presenten conductes de risc social. Cap d’ells presenta addicció a drogues via parenteral.
Conclusions: La taxa de TV del VHC és del 11,7% i està influïda principalment per la càrrega viral materna, influint també l’ hepatitis crònica en la gestant, la menor edat de la mare i la sociopatia. La cesària electiva podria ser factor protector de la TV del VHC. El 72,7% dels nens infectats guareixen espontàniament la infecció, sobretot durant els tres primers anys de vida. La sociopatia dels seus pares influeix en l’evolució física, social i psiquiàtrica dels nens infectats.Introduction: The VT-HCV occurs in 5-15% of cases and depends on maternal risk factors, obstetric and neonatal. So far there is little information on the evolution of infected children beyond the first two or three years. The aim of this study was to determine the rate of VT-HCV, risk factors and long-term evolution of infected children. Patients and Methods: Prospective cohort study of 120 HCV-infected pregnant women and their children born at the Hospital del Mar in Barcelona between January 1994 and December 1996, with follow-up of 36 months for all children and 17-20 years for infected children. Maternal and obstetric data recorded and performed HCV RNA qualitative and quantitative pregnant women for childbirth. Data recorded track of neonatal and children every three months to a year and a half every 6 months to 3 years, collecting growth data and testing liver, HCV antibody and HCV-RNA. The infected children are visited every six months, performing liver tests and HCV-RNA, and in case of chronic hepatitis, liver biopsy. Results: The average age of mothers was 28.2 ± 5.0 years. The route of transmission of HCV was mainly intravenous drug addiction (ADVP), present in 79 mothers (65.8%); 22 mothers (18.3%) were diagnosed with chronic active hepatitis; 50 (41.7%) were coinfected with HIV and 34 (28.8%) consumed heroin during pregnancy. HCV infection were in 14 newborns, giving a flat rate of HCV 11.7% (95% CI 6.0 to 17.5). This rate increases to 14% (95% CI 6.7 to 21.3) in HCV-RNA positive mothers, at 16.0% (95% CI 11.9 to 20.2) in HIV co-infected mothers, at 29.2% (95% CI 11.0 to 47.4) in mothers with chronic hepatitis and 21.8% (95% CI 11.0 to 32.7) in mothers with sociopath. Risk factors for vertical transmission were statistically significant maternal viral load to part with a flat rate of mothers with HCV viral load> 3.9 x105 copies / mL of 40% (95% CI: 18.5 to 61 5), the presence of chronic hepatitis maternal, maternal age lower than 25.0 ± 4.7 years, maternal sociopath and the presence of neonatal drug abstinence syndrome. There are risk factors for HIV and HCV coinfection mother, the ADVP, the type of part or the sex of the baby. None of the 13 children born by elective caesarean section have been infected by VT. Monitoring of infected children show good clinical evolution, without acute hepatitis but mild activity chronic hepatitis on liver biopsy. The spontaneous clearence rate is 72.7% and the factors that influence is lower maternal HCV viral load at delivery and serotypes non-1. Children with spontaneous clearance showed less determinations positive HCV-RNA and lowed viral load during the first year of life. HCV infected children followed until adulthood have needed psychiatric monitoring in the 63% cases and 73% have social risk behaviors. None of them appears intravenous drug addiction. Conclusions: The rate of HCV TV is 11.7% and is influenced mainly by maternal viral load, also influencing the chronic hepatitis in pregnant women, the younger of the mother and sociopath. The elective cesarean might be protective factor. 72.7% of children infected have spontaneous clearence, especially during the first three years of life. The sociopath of their parents influence the physical, social and psychiatric evolution of infected children.
28
Williams, John. "A mathematical model of the dynamics of hepatitis B virus transmission in the UK under the influence of different vaccination control strategies." Thesis, University of Oxford, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.298721.
Full text
29
Palmateer, Norah E. "Determining the effectiveness of harm reduction interventions in the prevention of hepatitis C virus transmission among people who inject drugs in Scotland." Thesis, University of Glasgow, 2014. http://theses.gla.ac.uk/5234/.
Full textAbstract:
The hepatitis C virus (HCV) is highly prevalent among people who inject drugs (PWID) in Scotland and the large majority of new HCV infections occurring in Scotland are within this population group. Harm reduction interventions, mainly sterile injecting equipment provision (IEP) and opioid substitution treatment (OST), to prevent the transmission of blood-borne viruses among PWID, were implemented in Scotland in the late 1980s/early 1990s. More recently, government policy initiatives, particularly the Hepatitis C Action Plan for Scotland, have stipulated the scale-up of these interventions. The overarching aim of this thesis was to investigate the impact of harm reduction interventions on the transmission of HCV among PWID in Scotland. Five secondary objectives were addressed in order to fulfil the main aim: (i) to review the international literature on the effectiveness of IEP and OST in preventing HCV transmission; (ii) to determine the association between self-reported sharing of needles/syringes and incident/prevalent HCV infection; (iii) to determine the association between sharing non-needle/syringe injecting paraphernalia and incident HCV infection; (iv) to determine the incidence of HCV among PWID in Scotland; and (v) to determine the association between self-reported uptake of IEP/OST and incident HCV infection. To address the first thesis objective, a systematic review of the literature was undertaken to identify existing international research evidence (published up to March 2007) for the effectiveness of harm reduction interventions. While HCV was the main outcome of interest, HIV and injecting risk behaviour (IRB) were also considered. A review of reviews approach identified: insufficient evidence that sterile needle and syringe provision (NSP) was effective in preventing HCV transmission; tentative evidence that NSP was effective in preventing HIV transmission; sufficient evidence to support the effectiveness of NSP in reducing self-reported IRB; and little to no evidence on needle/syringe vending machines, outreach NSP or the provision of other injecting paraphernalia (spoons, filters, water) in relation to any of the outcomes. With regard to OST, the findings were: insufficient evidence to show that OST has an impact on HCV transmission; sufficient evidence to support the effectiveness of continuous OST in reducing HIV transmission; and sufficient evidence to support the effectiveness of OST in reducing IRB by reducing the frequency of injection, the sharing of injecting equipment and injecting risk scores. An update to the review of reviews was undertaken to include literature published through March 2011, and found that little changed as a result of additional published reviews: in the main, the evidence statement for the effectiveness of OST with regard to HCV was upgraded from insufficient to tentative. The finding of weaker evidence with regard to biological outcomes (e.g. HCV, HIV), as compared with behavioural outcomes, indicated that low levels of IRB may be insufficient to reduce high levels of transmission, particularly for HCV. The subsequent chapter aimed to address the second thesis objective, by summarising, and exploring factors that explained the variation in, the measure of association between self-reported sharing of needles/syringes and HCV prevalence/incidence among PWID. A systematic review and meta-analysis were undertaken to identify and combine the results of European studies of HCV prevalence (or incidence) among those who reported ever/never (or recent/non-recent) sharing of needles/syringes. Among the 16 cross-sectional studies and four longitudinal studies identified, the pooled prevalence of HCV was 59% among PWID who reported never sharing needles/syringes and the pooled incidence of HCV was 11% among PWID who reported not recently sharing needles/syringes. Random effects meta-analysis generated a pooled odds ratio (OR) of 3.3 (95% confidence interval [CI] 2.4-4.6), comparing HCV infection among those who ever (or recently) shared needles/syringes relative to those who reported never (or not recently) sharing. Differences in pooled ORs were found when studies were stratified by recruitment setting (prison vs. drug treatment sites), recruitment method (outreach vs. non-outreach), sample HCV prevalence and sample mean/median time since onset of injecting. High incidence/prevalence rates among those who did not report sharing needles/syringes during the risk period may be a result of a combination of unmeasured risk factors (such as sharing non-needle/syringe injecting paraphernalia) and reporting bias. Study design and population were found to be modifiers of the size and strength of association between HCV and needle/syringe-sharing. To address the third thesis objective, the risk of HCV associated with sharing injecting paraphernalia (spoons, filters and water) was investigated using data from the 2008-09 and 2010 sweeps in a series of national cross-sectional surveys of PWID in Scotland, collectively called the Needle Exchange Surveillance Initiative (NESI). Logistic regression was used to examine the association between recent HCV infection (anti-HCV negative and HCV-RNA positive individuals) and self-reported measures of injecting equipment sharing in the six months preceding interview. Twelve percent of the sample reported sharing needles/syringes and 40% reported sharing paraphernalia in the previous six months. The adjusted odds ratios (AORs) for sharing needles/syringes (with or without paraphernalia) and sharing only paraphernalia in the last six months were 6.7 (95% CI 2.6-17.1) and 3.0 (95% CI 1.2-7.5), respectively. Among those who reported not sharing needles/syringes, sharing spoons and sharing filters were significantly associated with recent HCV infection (AOR 3.1, 95% CI 1.3-7.8 and 3.1, 95% CI 1.3-7.5, respectively); sharing water was not. This cross-sectional approach to the analysis of the association between sharing paraphernalia and incident HCV infection demonstrated consistent results with previous longitudinal studies. The prevalence of paraphernalia-sharing in the study population was high, potentially representing a significant source of HCV transmission. Addressing the fourth and fifth thesis objectives, a method to determine the incidence of HCV among PWID using a cross-sectional design was applied, and the associations between self-reported uptake of harm reduction interventions (OST and IEP) and recent HCV infection were examined. This was undertaken on data from the first sweep (2008-09) of NESI. Twenty-four recent HCV infections (as defined above) were detected, yielding incidence rate estimates ranging from 10.8-21.9 per 100 person-years. After adjustment for confounders, those with high needle/syringe coverage had reduced odds of recent infection (AOR 0.32, 95% CI 0.10-1.00, p=0.050). In the Greater Glasgow and Clyde region only, there were reduced odds of recent infection among those currently receiving OST, relative to those on OST in the last six months but not currently (AOR 0.04, 95% CI 0.001-1.07, p=0.055). The effect of combined uptake of OST and high needle/syringe coverage was only significant in unadjusted analyses (OR 0.34, 95% CI 0.12-0.97, p=0.043; AOR 0.48, 95% CI 0.16-1.48, p=0.203). The final analysis chapter built on the previous chapter investigating the association between uptake of harm reduction interventions and recent HCV infection, by using data from three sweeps of the NESI survey, undertaken in 2008-09, 2010 and 2011-12. A framework to triangulate different types of evidence – ‘group-level/ecological’ and ‘individual-level’ – was applied. Data on service provision (injecting equipment provision and methadone dispensation) were also collated and analysed.
30
Moal, Valérie. "Infections par virus de l'hépatite E après transplantation rénale à Marseille." Thesis, Aix-Marseille, 2012. http://www.theses.fr/2012AIXM5042.
Full textAbstract:
Le virus de l‘hépatite E (VHE) est endémique mondialement. Dans les pays en voie de développement, le VHE est une cause majeure d'hépatite aiguë et l'hépatite E est une maladie du péril fécal, transmise par la consommation d'eau contaminée. Le taux de mortalité de l'hépatite E aiguë en situation d'épidémie est estimé entre 0,2 et 4%. Dans les pays développés, l'hépatite E d'origine autochtone a émergé au début du XXIème siècle et un réservoir porcin à l'origine de transmissions zoonotiques du VHE a été établi. En 2008, pour la première fois, des formes chroniques de l'hépatite E ont été décrites révélant que le VHE était également une cause d'hépatite chronique et de cirrhose. Ces nouvelles formes d'hépatite E ont été rapportées chez des patients immunodéprimés pour transplantation d'organes solides, par le virus de l'immunodéficience humaine ou par des hémopathies malignes ou les traitements de ces hémopathies. Les travaux de cette Thèse ont eu pour objectifs de décrire les aspects cliniques puis épidémiologiques de l'hépatite E, d'étudier certains aspects immunologiques de l'hôte et certains aspects virologiques des VHE dans le but de comprendre les mécanismes conduisant au développement d'une hépatite E chronique dans la population des patients transplantés d'un rein suivis au CHU de Marseille. Nous avons décrit dans une étude rétrospective les caractéristiques et l'histoire naturelle de 16 infections autochtones diagnostiquées devant une hépatite inexpliquée. Nous avons décrit une évolution majoritairement chronique de l'hépatite E et son potentiel cirrhogèneHepatitis E virus (HEV) is endemic worldwide. In developing countries, HEV is a major cause of acute hepatitis and hepatitis E is a disease transmitted by the faecal-oral route through contaminated water. The estimated mortality rate of acute hepatitis E in the setting of outbreaks ranges from 0.2 to 4%. In developed countries, hepatitis E of autochthonous origin emerged at the beginning of twenty-first century and a porcine reservoir for HEV has been established that is a source for zoonotic transmission. In 2008, for the first time, chronic forms of hepatitis E have been reported showing that HEV was also a cause of chronic hepatitis and cirrhosis. These new forms of hepatitis E have been reported in immunocompromised patients due to solid organ transplantation, infection by human immunodeficiency virus, hematological malignancies or treatment of these malignancies. The objectives of this Thesis have been to describe the clinical and epidemiological features of hepatitis E, to examine some immunological aspects of the host and some virological aspects of HEV in order to understand the mechanisms leading to the development of chronic hepatitis E in the population of kidney transplant recipients followed at the University Hospital of Marseille. In a retrospective study, we described the characteristics and natural history of 16 HEV infections diagnosed in patients presenting with unexplained hepatitis. We described that hepatitis E progressed the most frequently towards chronicity and possibly towards liver cirrhosis. We showed that after dose reduction of immunosuppressants, more than half of the chronic infections resolved
31
URAN, MARTIN MARIE-HELENE. "Transmission antenatale du virus de l'hepatite b : recurrence de l'infection avec hepatite mortelle chez deux nouveau-nes d'une mere porteuse chronique de l'antigene hbs." Lyon 1, 1989. http://www.theses.fr/1989LYO1M036.
Full text
32
Sicart-Prieu, Marie-Christine. "Evaluation du risque de transmission de l'infection virale C par les pinces à biopsie au cours d'endoscopie digestive." Montpellier 1, 1995. http://www.theses.fr/1995MON11177.
Full text
33
Andriamandimby, Soa Fy. "Infection par le virus de l'Hépatite B à Madagascar : prévalence, facteurs de risque d'infection, diversité génétique, origine et dynamique de transmission." Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLV046.
Full textAbstract:
Madagascar fait partie de la zone de haute endémicité pour l‟hépatite B dont le profil de circulation varie selon la ruralité de la zone d‟habitation. De par son insularité et les origines de ses peuplements, nous avons supposé que ce profil de circulation du VHB était dû à la variabilité du VHB et à l‟hétérogénéité du profil de transmission. Ce projet de thèse a pour objectif principal de déterminer les facteurs épidémiologiques et moléculaires influençant la dynamique de transmission et l‟évolution vers les complications de l‟infection par le virus de l‟hépatite B à Madagascar. Résultats : la séroprévalence globale pondérée en Ag HBs est de 6,9% avec des variations allant de 0% à 26% selon les zones géographiques considérées. La prévalence augmente en s‟éloignant des grandes villes et des principales routes nationales les reliant et chez les individus à faible statutsocio-économique. L‟étude du flux génétique des souches virales de l‟hépatite B montre que les zones les plus reculées représentent un réservoir pour la dissémination du virus. L‟infection par le virus de l‟hépatite B est responsable de 31% des maladies hépatiques chroniques rencontrées dans les services hospitaliers investigués à Antananarivo. L‟introduction du VHB s‟est probablement faite au cours du XIXème siècle. Sa propagation à l‟intérieur du pays a pris une allure exponentielle durant les années 80s probablement durant les épidémies de paludisme et suite à des réutilisations des matériels d‟injections. Conclusion : Les résultats de ces différents travaux nous ont permis de plaider pour une politique de lutte visant en particulier les zones très reculées de l‟île où la prévalence en AgHBs est la plus importanteMadagascar is part of endemic region of HBV. Distribution is different in rural and urban area. The historic of human settlement and its insularity might impact distribution and molecular characteristic of HBV in Madagascar, we then supposed that difference observed in distribution and prevalence of HBV were due to viral variability and different pattern of viral transmission. Therefore, the main objective of this thesis was to determine molecular and epidemiological pattern that may influence dynamic transmission and complications of infection. Results: weighted prevalence of HBsAg was 6.9%. It varied from 3% to 26% according to area of sampling. Populations with a low socio-economic status and those living in rural areashad a significantly higher seroprevalence of HBsAg. Gene flow study showed rural area remain important in virus diffusion.HBV infection was found to be responsible of 31% of chronic liver disease encountered in the main public hospital in the capital of the country. Because of its recent emergence, its introduction dated from XIX century during colonization period. Its expansion during 1980s might be due to use of unsafe injection material mainly during malaria epidemic. Conclusion: The result of these work allowed us to advocate for a policy of struggle, in particular in the very remote areas of the island where the HBsAg prevalence is the most important and where care and preventive measures such as vaccinations are scarce
34
Epeirier, Jean-Marie. "Evaluation de la transmission sexuelle du virus de l'hépatite C : étude prospective de 63 couples (associée à l'étude du génotype viral chez 12 couples dont les 2 conjoints sont infectés par le VHC)." Montpellier 1, 1995. http://www.theses.fr/1995MON11127.
Full text
35
Wasserscheid, Katharina [Verfasser], and Barbara [Akademischer Betreuer] Gärtner. "Eine Kosten-Effektivitäts-Analyse der Impfung von Blutspendern zur Reduktion der Transmission des Hepatitis-B-Virus im Rahmen von Bluttransfusionen / Katharina Wasserscheid ; Betreuer: Barbara Gärtner." Saarbrücken : Saarländische Universitäts- und Landesbibliothek, 2017. http://d-nb.info/1132133750/34.
Full text
36
Chidaine, Stéphane. "Epidémiologie du virus de l'hépatite C (VHC) en Afrique et dans l'Océan Indien : prévalence et transmission; revue bibliographique." Bordeaux 2, 2000. http://www.theses.fr/2000BOR2M044.
Full text
37
Claret, Teruel Gemma. "Història natural i factors pronòstics de la infecció per transmissió vertical del virus de la hepatitis C. Efectes del tractament antiviral i implicació de la co-infecció pel virus de la immunodeficiència humana." Doctoral thesis, Universitat de Barcelona, 2009. http://hdl.handle.net/10803/2498.
Full textAbstract:
La infecció pel VHC és la principal causa d'hepatopatia crònica arreu del món. Els nens constitueixen una petita proporció de la població infectada i en l'actualitat la principal via d'adquisició de la infecció pel VHC en la infància és la transmissió vertical. És probable que els pacients infectats durant la infancia, tal com passa en els adults, es mantinguin asimptomàtics durant un llarg període de temps, tot i que s'han descrit casos de cirrosi en un temps inferior als 10 anys. Donada l'absència de manifestacions clíniques en les primeres fases de la infecció, s'han estudiat diversos marcadors analítics per a definir la progressió de la malaltia.
En l'actualitat, es disposa d'un tractament antiviral eficaç (interferó pegil·lat més ribavirina) per a la infecció crònica pel VHC. Aquest tractament ha estat autoritzat recentment per a la població pediàtrica. L'absència de comorbilitats i el curt temps d'evolució de la infecció converteixen al nen infectat pel VHC en el candidat ideal per a obtenir altes taxes de curació de la malaltia.
En els darrers anys, la infecció pel VIH ha esdevingut una patologia de curs crònic mentre que l'hepatopatia és actualment una de les principals causes de morbilitat i mortalitat en els pacients co-infectats. En el pacient pediàtric co-infectat les consideracions prèvies sobre l'inici de tractament específic esdevenen especialment rellevants, ja que les probabilitats d'èxit del mateix probablement es relacionin amb la seva precocitat.
Els objectius principals del nostre estudi són definir les característiques de la transmissió vertical del VHC en el nostre medi, descriure la història natural de la infecció crònica pel VHC en l'edat pediàtrica i establir el paper de la co-infecció pel VIH en l'evolució natural de la infecció crònica pel VHC en el nen.
Per això hem dissenyat dos estudis prospectius observacionals que inclouen els fills de mares infectades pel VHC nascuts al nostre centre entre gener del 1999 i desembre del 2006 (estudi 1) i els nens infectats pel VHC controlats en el nostre centre (estudi 2). Tots elspacients han estat seguit de forma prospectiva.
Les principals conclusions dels estudis són les següents: Estudi 1: La taxa prevalença de la infecció pel VHC en les gestants és del 0.49%. La taxa de transmissió vertical del VHC és del 2.8%. Existeix una relació entre la co-infecció materna pel VIH i la transmissió vertical del VHC en el grup de pacients estudiats. Estudi 2: La majoria dels pacients romanen asimptomàtics i sense troballes clíniques al llarg del seguiment. La meitat dels pacients estan infectats pels genotips 1a o 1b; en els fills de mare UDVP, hi predominen les infeccions pels genotips 3 i 4. La biòpsia hepàtica mostra signes d'hepatitis crònica en la majoria dels casos. D'entre els pacients no tractats, un 12% evolucionen al clearence espontani de la infecció (tots ells són pacients infectats per transmissió vertical) mentre que el 82% dels pacients evolucionen a un patró d'hepatitis crònica. La taxa de prevalença de cirrosi és de l'1.8%. Només 4 de 27 pacients tractats amb interferó en monoteràpia durant 12 mesos assoleixen el clearence de la virèmia. El 86% dels pacients pateixen efectes secundaris del tractament, tot i que solen ser lleus. Els pacients co-infectats mostren unes xifres màximes d'ALT més altes que la resta i evolucionen en la majoria de casos seguint un patró d'hepatitis crònica.
HCV infection is the main cause of hepatopathy worldwide. Children represent a small proportion of the infected people and vertical transmision is the main way of acquisition in childhood.
Patients infected during childhood will probably remain asymptomatic for a long time, as happens in adults, but some cases of cirrhosis have been described. Regarding the lack of clinical manifestations during the first years of the infection, several serum markers have been studied to define the progression of the illness.
Nowadays an efective treatment is available (pegilated interferon plus ribavirin) for the chronic HCV infection and it has been recently authorised for childhood. The absence of comorbilities and the short course of the infection will probably lead to a higher rate of response in this group of patients. Early treatment will probably be effective also in HIV co-infected patients.
Main objectives of our study are to define HCV vertical transmission in our media, to describe natural history of the chronic HCV infection in childhood and to stablish the role of HIV co-infection in the evolution of HCV infection.
Two prospective studies have been conducted. They include children from HCV infected mothers born in our center between january 1999 and december 2006 (Study 1) and HCV infected children visited in our center (Study 2).
Main conclusions of our study are: Study 1: Prevalence rate of HCV infection among pregnant women is 0.49%. HCV vertical transmision is 2.8%. There is a relation between vertical transmision and maternal HIV co-infection. Study 2: Most of the HCV infected patients remain asymtomatic during the follow up. Half of the patients belong to 1a or 1b HCV genotipes; in children born from drug users genotipes 3 and 4 are frequent. 12% of the patients that have'nt received treatment experiment spontaneous clearence of the infection (all are vertically infected) while 82% end in a chronic hepatitis. Prevalence rate of cirrhosis is 1.8%. Only 4 of 27 patients treated with interferon reach the clearence of the viremia and 86% suffer secundary effects, usually mild. Co-infected patients have higher ALT determinations and usually end in a chronic hepatitis.
38
Zarski, Jean-Pierre. "Virus de l'hépatite B : mise en évidence du génome viral et étude des mutations pré-C." Université Joseph Fourier (Grenoble ; 1971-2015), 1996. http://www.theses.fr/1996GRE10217.
Full textAbstract:
Ce travail rapporte dans sa premiere partie, l'interet de la detection de l'adn du virus de l'hepatite b (vhb) dans le serum, par differentes methodes permettant une quantification de la viremie. Apres avoir mis au point une technique d'hybridation en phase liquide avec marquage a l'iode 131, l'auteur montre son interet dans le suivi des malades sous traitement antiviral. La technique de pcr est plus sensible et permet dans certains cas de differencier les vrais des faux-positifs. La technique d'hybride capture avec revelation en chemiluminescence, a une sensibilite equivalente et est plus facile a realiser en routine. Par contre, la quantification bien que rapportee en picogrammes/ml, n'est pas comparable a celle de la technique d'hybridation en phase liquide. Enfin, en cas de co-infection par les deux virus des hepatites b et c, il existe une inhibition reciproque de la replication de chacun des virus a la fois qualitative et quantitative. L'objet de la 2eme partie du travail est l'etude des mutations de la region pre-c au sein d'une famille turque dont la mere etait porteuse d'une hepatite chronique avec anticorps anti-hbe positif et les enfants ayant plusieurs profils de replication virale. Dans ce travail, il est montre qu'il existe une probable transmission materno-foetale de la mutation 1896 et qu'il est possible meme d'observer cette mutation en cas de guerison presumee de l'hepatite avec presence de l'anticorps anti-hbs mais pcr positive.
39
L'Hôte, Catherine. "Etude rétrospective sur les patients transfusés dans un service de réanimation médicale de 1980 à 1985 et essai de suivi post-transfusionnel." Montpellier 1, 1993. http://www.theses.fr/1993MON11175.
Full text
40
Fenaux, Honorine. "Étude de la circulation du virus de l’hépatite E entre l’Homme et l’environnement par caractérisation moléculaire de souches humaines et environnementales." Thesis, Université de Lorraine, 2019. http://www.theses.fr/2019LORR0108.
Full textAbstract:
Le virus de l’hépatite E (VHE) est responsable d’hépatites chez l’Homme. Bien que l’infection par le VHE soit le plus souvent aiguë, des formes chroniques ont été décrites chez des sujets immunodéprimés. Quatre génotypes majeurs sont décrits. Les génotypes 1 et 2 circulent dans les pays en voie de développement où ils n’infectent que l’Homme avec une transmission hydrique. Les génotypes 3 et 4 circulent plutôt dans les pays développés, où ils peuvent infecter l’Homme mais aussi des animaux (cochons, sangliers et cerfs), se transmettent à l’Homme par l’ingestion de viande crue ou mal cuite d’un animal infecté. Cependant les voies de transmission du VHE dans les pays développés ne sont pas encore claires et une voie de contamination hydrique est suspectée. L’objectif de ce travail était de clarifier la circulation du VHE dans le nord-est de la France (exemple de pays développé). Nous avons étudié des prélèvements humains, de sangliers, de cochons de ferme, ainsi que des effluents d’un abattoir porcin, des eaux d’entrée d’une station d’épuration (STEP) et des moules d’eau douce utilisées pour concentrer des virus éventuellement présents dans des rivières. Le VHE de génotype 3 a été retrouvé dans des prélèvements humains, de sangliers, d’effluents d’abattoir et de STEP. Plusieurs substitutions d’acide aminé ont été mises en évidence. Certaines sont de possibles signatures d’origine du prélèvement. Quelques-unes entraînent des modifications d’antigénicité et d’hydrophobie prédites, pouvant avoir des conséquences sur le comportement du virus et sa circulation. Enfin, les prélèvements de STEP comportaient un mélange de variants d’origines diverses, en faveur d’un rôle de l’eau dans la circulation du VHE. Des tests fonctionnels doivent être effectués afin de mesurer l’impact des substitutions observéesHepatitis E virus (HEV) causes hepatitis in humans. Although HEV infection is mainly self-limiting, chronic forms have been described in immunocompromised patients. Four major genotypes have been described. Genotypes 1 and 2 circulate in developing countries where they only infect humans with a waterborne transmission. Genotypes 3 and 4 mainly circulate in developed countries where they infect humans and some animals (pigs, wild boars, deer), and are transmitted to humans through consumption of an infected animal’s raw or undercooked meat. However, HEV transmission paths are still unclear in developed countries and a waterborne transmission is suspected. The aim of this work was to clarify HEV circulation in North-Eastern France (as a model of a developed country). We have studied human, wild boar, farm pig samples, effluent water from a pig slaughterhouse, incoming water of a wastewater treatment plant (WWTP) and little pure water mussels that can concentrate viruses possibly present in rivers. Genotype 3 HEV has been recovered from human, wild boars, slaughterhouse and WWTP samples. Several amino acid substitutions have been brought out. Some are possible signatures of a sample’s origin. Some lead to modifications in predicted antigenicity and hydrophobicity, which can have consequences on the virus’ behaviour and circulation. Finally, the WWTP samples showed a mixture of variants from different origins, in favour of a role of water in HEV circulation. Functional tests need to be performed to measure the impact of the observed substitutions
41
Jordier, Edme. "Epidémiologie moléculaire du virus de l'hépatite C (VHC) chez les donneurs de sang français entre 2008 et 2011 : caractérisation de génomes complets du VHC appartenant au génotype 2." Thesis, Aix-Marseille, 2013. http://www.theses.fr/2013AIXM5095.
Full textAbstract:
La distribution des génotypes du virus de l’hépatite C (VHC). chez les donneurs de sang Français entre 2008 et 2011 a été analysée afin d’actualiser nos connaissances. Le génotypage des souches a permis d’identifier la diversité des génotypes circulants. Les sous-types 1a, 1b et 3a sont majoritairement retrouvés (80% des souches). L’analyse phylogénétique a démontré une grande variabilité chez les types 2 et 4 représentés par de nombreux sous-types. Les résultats montrent que les comportements à risque tendent à influencer et redessiner la distribution de ces génotypes dans la population générale. Certains sous-types se répandent dans des groupes à risque où ils finissent par adopter un profil épidémique. Enfin, la sélection des donneurs et la mise en place de tests diagnostiques ont permis de rendre la contamination transfusionnelle négligeable. Les données épidémiques obtenues ont été enrichies de nouvelles connaissances sur l'évolution et la classification du VHC. 15 séquences codantes complètes de plusieurs souches appartenant au type 2 ont été caractérisées. L’analyse phylogénétique révèle 2 clusters distincts. Le cluster 1 comprend la plupart des souches tandis que le cluster 2 comprend le sous-type 2l. Les génomes obtenus ont un ORF de 9042 à 9108 bases (3014 à 3036 acides aminés). Les distances moyennes entre sous- types sont égales à 20% dans le cluster 1 et 26% entre les deux clusters. La bifurcation entre clusters a eu lieu tôt lors de l'évolution du virus. L'insertion de 60 bases dans la région NS5A caractéristique du type 2 est absente chez les 2l. Donc, l'apparition et la fixation de celle-ci sont tardives dans l'évolution du virusThe distribution of genotypes of hepatitis C virus (HCV) infection among blood donors French between 2008 and 2011 was analyzed in order to update our knowledge. Genotyping strains identified the diversity of circulating genotypes. Subtypes 1a, 1b and 3a are found predominantly (80 % of strains). Phylogenetic analysis showed a great variability in types 2 and 4 represented by many subtypes. The results show that risk behaviors tend to influence and reshape the distribution of these genotypes in the general population. Some subtypes are spreading risk groups where they eventually adopt an epidemic profile. Finally, donor selection and implementation of diagnostic tests reduced drastically blood contamination. Epidemic data were enriched of new knowledge about the evolution and classification of HCV. 15 complete coding sequences of several strains of type 2 have been characterized. Phylogenetic analysis reveals two distinct clusters. Cluster 1 includes most strains while cluster 2 includes subtype 2l. Genomes obtained have an ORF of 9042 to 9108 bases (3014-3036 amino acids). The average distances between subtypes are equal to 20% in cluster 1 and 26 % between the two clusters. The bifurcation between clusters occurred early during the evolution of the virus. The insertion of 60 bases in the NS5A region characteristic of Type 2 is absent in 2l. So the appearance and fixing it is late in the evolution of the virus
42
Marsaud, Françoise. "Etude de la séroprévalence du virus C dans la population soignante d'un service d'hémodialyse et d'un service d'hépato-gastro-entérologie." Bordeaux 2, 1994. http://www.theses.fr/1994BOR2M050.
Full text
43
Khamduang, Woottichai. "Analyse des mutants du virus de l'hépatite B (VHB) chez des patients co-infectés par le VIH et le VHB en Thaïlande." Thesis, Tours, 2011. http://www.theses.fr/2011TOUR3317/document.
Full textAbstract:
L’infection par le VHB est endémique en Thaïlande. Malgré l’introduction des programmes de vaccination contre le VHB, la transmission périnatale reste une cause majeure d’infection chronique. Les objectifs de ce travail étaient d’identifier les mutants du VHB pouvant être associés à des échecs de vaccination, de diagnostic et de thérapeutique. Le travail présenté ici est divisé en trois parties. Dans une première partie, nous avons analysé la prévalence de la transmission périnatale du VHB dans une cohorte issue d’un protocole thérapeutique de prévention de la transmission materno-fœtale du VIH. Nous avons cherché à caractériser les mutants d’échappement à la vaccination contre le VHB. Parmi 3349 femmes enceintes séropositives pour le VIH, l’antigène (Ag) HBs était positif dans 7% des cas. L’Ag HBs était détectable à l’âge de 2 et 18 mois chez 11 enfants nés de mères porteuses chroniques. Les variants du VHB présents au sein de 9 de ces paires mère-enfant ont pu être étudiés après séquençage et clonage. Trois types de transmission du VHB ont pu être décrites ; i) transmission de variants non mutés par les mères présentant une charge virale VHB élevée ii) transmission d’un virus mutant minoritaire isolé chez la mère, et iii) transmission de mutants déjà présents à plus de 20% chez la mère. La capacité in vitro de ces mutants à échapper à la réponse neutralisante anti-HBs sera étudiée en utilisant un modèle de pseudo-particules portant les mutations identifiéesThailand is an endemic area for chronic HBV infection. Despite implementation of HBV vaccination, perinatal HBV transmission remains a major cause of chronic infection. This study aimed at identifying HBV mutants that may be associated with vaccine failure, misdiagnosis of chronic HBV infection and antiviral treatment failure. The dissertation is divided in three parts. In the first part, we analyzed the prevalence of perinatal HBV transmission in a large HIV prevention cohort in Thailand and characterized the HBV vaccine escape mutants. Among 3,349 HIV-infected pregnant women, 7% were found HBsAg positive. Eleven children born to HBsAg-positive mother were found HBsAg-positive at 2–18 months of age. Complete series of samples were available for 9 mother-child pairs. Based on direct sequencing and cloning analysis, 3 patterns of transmission were observed : i) transmission of wild-type variants from mothers with high HBV DNA level, ii) transmission of maternal minor variant and iii) transmission of variants already present in maternal blood samples. The capacity of HBV variants to escape from anti-HBs neutralization in vitro will be further studied using HBV-pseudoviral particles harboring the characterized mutations
44
Wen, Wan-Hsin, and 文萬欣. "Familial Causes of Failed Immunoprophylaxis against Hepatitis B Virus Transmission." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/33022818864444696643.
Full textAbstract:
碩士國立臺灣大學
臨床醫學研究所
93
Since the nationwide hepatitis B vaccination program was launched in 1984, the seropositive rate of hepatitis surface antigen (HBsAg), the incidence/mortality rate of fulminant hepatitis and the incidence rate of hepatocellular carcinoma in Taiwanese children have declined significantly. However, active/passive immunoprophylaxis against hepatitis B virus (HBV) can not eradicate transmission completely. Less than 10% infants born to HBsAg positive mothers, especially e antigen (HBeAg) positive ones, will still be infected and become victims of chronic hepatitis B. Possible causes of immunoprophylaxis failure (IF) include: intrauterine infection, surface gene mutant HBV infection, high level of maternal viremia and the host factors that lead to non-response to the vaccine. The aim of the study is to compare the IF rate of the younger child of HBeAg positive mothers, whose elder child is a case of IF, to that of other HBeAg positive mothers, whose elder child is not a case of IF, to see if there is any familial cause of failed immunoprophylaxis. HBsAg positive mothers with more than one child were enrolled from mothers of HBV carrier children followed-up in our hospital and women delivered in our hospital. The mothers were HBeAg positive when the children were born. Those children who did not receive hepatitis B immunoglobulin (HBIG), or did not receive HBIG within 24 hrs after birth, or did not complete hepatitis B vaccine injection, were excluded. If more than two children in the same family fulfilled the criteria, only the first two were recruited. The HBsAg status, age, sex, delivery mode, maternal age at delivery, and paternal HBsAg status of these children were analyzed. A total of 98 families were collected. In 9 of the 98 families, both children were cases of IF. In 28 families, only the elder one was HBsAg positive. In 15, only the younger one was HBsAg positive, and in 46, both were HBsAg negative. The IF rate of the elder child (37/98, 37.8%) was significantly higher than that of the younger one (24/98, 24.5%) (p = 0.0474). However, the IF rate of the younger child in the families with an elder child who was a case of IF (9/37, 24.3%), did not differ from that in the families with an elder child who was a not case of IF (15/61, 24.6%) (p = 0.976). In addition, the maternal age at delivery was significantly younger in those families (N=52) with children infected by HBV than that in the families (N=46) without children infected by HBV (p < 0.05). We also reported other 8 cases of IF. Their mothers were HBeAg negative at delivery and there 8 cases received HBV vaccines but no HBIG. More than half of them have siblings born within 3 years of their births and the mothers were HBeAg positive when the siblings were born. It is possible that these 8 cases were born at the HBeAg seroconversion stage of their mothers and the maternal HBV DNA amount was still high although the maternal HBeAg was negative. In conclusion, our present result did not find differences between the IF rates of the younger child in the families with an elder child who was a case of IF and that in the families with an elder child who was a not case of IF. Our present finding indicated that the IF rate was higher in the older children than in the younger ones of HBeAg positive mothers. A younger maternal age at delivery was also noted in those families with children infected by HBV than that in the families without children infected by HBV. A younger maternal age at delivery may be associated with a heavier viral load and then result in failed immunoprophylaxis.
45
Miller, Emma Ruth. "HCV infection in South Australian prisoners : prevalence, transmission, risk factors and prospects for harm reduction." 2006. http://hdl.handle.net/2440/37857.
Full textAbstract:
This thesis aimed to describe the epidemiology of HCV in South Australian prisons - prevalence, transmission and risk factors. This thesis also aimed to determine the impact of incarceration on reported risk behaviours. A related objective was to evaluate the epidemiological effectiveness of the ELISA - 3 HCV antibody test using PCR as the gold standard. Finally, this thesis aimed to explore the potential for minimising HCV risk in the South Australian prison population. Methods: Two case note audits were conducted at each of eight publicly operated SA prisons ( in summer and winter ) to identify any documented HCV - antibody test results. Prisoners recruited at entry to prison were offered tests for HCV - antibody and completed a pre - entry risk factor survey. Participants completed additional risk factor surveys and ( if HCV - negative at last test ) underwent further antibody tests at three - monthly intervals for up to 15 months. A sample of participants also provided blood specimens for HCV - RNA testing. Limited stakeholder consultations with prison officers and nurses were also conducted. Quantitative data were analysed using univariate and multivariate techniques. Results: 1347 case notes were audited in summer, and 1347 in winter and an overall HCV prevalence of 42 % was estimated. In both univariate and multivariate analyses, HCV prevalence was significantly higher in female prisoners ( 65 % ), those aged above 28 years ( 48 % ), and in Indigenous prisoners originating from metropolitan areas ( 56 % ). Indigenous prisoners originating from remote areas had significantly lower HCV prevalence ( 20 % ). 666 prisoners were recruited at entry, and 42 % were estimated to be HCV - antibody positive. Three seroconversions were noted in 151 initially HCV - seronegative negative individuals followed up for a median time of 121 days - a rate 4.6 per 100 person years - but community exposure could not be ruled out. Overall agreement between HCV - antibody and HCV - RNA assays was 86 % ( 100% in the HCV negative samples ) - kappa = 0.71. Injecting history was highly prevalent in prison entrants ( 70 % ) and both community and prison injecting ( but not tattooing ) were independent predictors of entry HCV status. Prison history was also independently associated with entry HCV status. Injecting in prison during the study was infrequently reported, but significantly more likely in those testing HCV - antibody positive at prison entry ( risk ratio = 2.48, P = 0.046 ). Stakeholders were most supportive of strategies to increase education and to minimise risks associated with hair clippers, but did not support most other suggested preventive strategies. Other issues related to communicable diseases and infection control were explored in the stakeholder interviews. Conclusions: HCV prevalence in South Australian prisoners is extremely high and may have contributed to a ' ceiling effect ' , minimising the seroconversion rate observed in this population. Injecting is relatively infrequently reported in prison, but more likely in those already infected with HCV. Thus, contaminated injecting equipment represents a significant threat to other prisoners and prison staff. Strategies aimed at reducing HCV risk in prisons, which address the concerns of those expected to implement them, are proposed in this thesis.Thesis (Ph.D.)--School of Population Health and Clinical Practice, 2006.
46
Miller, Emma Ruth. "HCV infection in South Australian prisoners : prevalence, transmission, risk factors and prospects for harm reduction." Thesis, 2006. http://hdl.handle.net/2440/37857.
Full textAbstract:
This thesis aimed to describe the epidemiology of HCV in South Australian prisons - prevalence, transmission and risk factors. This thesis also aimed to determine the impact of incarceration on reported risk behaviours. A related objective was to evaluate the epidemiological effectiveness of the ELISA - 3 HCV antibody test using PCR as the gold standard. Finally, this thesis aimed to explore the potential for minimising HCV risk in the South Australian prison population.
Methods:
Two case note audits were conducted at each of eight publicly operated SA prisons ( in summer and winter ) to identify any documented HCV - antibody test results. Prisoners recruited at entry to prison were offered tests for HCV - antibody and completed a pre - entry risk factor survey. Participants completed additional risk factor surveys and ( if HCV - negative at last test ) underwent further antibody tests at three - monthly intervals for up to 15 months. A sample of participants also provided blood specimens for HCV - RNA testing. Limited stakeholder consultations with prison officers and nurses were also conducted. Quantitative data were analysed using univariate and multivariate techniques.
Results:
1347 case notes were audited in summer, and 1347 in winter and an overall HCV prevalence of 42 % was estimated. In both univariate and multivariate analyses, HCV prevalence was significantly higher in female prisoners ( 65 % ), those aged above 28 years ( 48 % ), and in Indigenous prisoners originating from metropolitan areas ( 56 % ). Indigenous prisoners originating from remote areas had significantly lower HCV prevalence ( 20 % ).
666 prisoners were recruited at entry, and 42 % were estimated to be HCV - antibody positive. Three seroconversions were noted in 151 initially HCV - seronegative negative individuals followed up for a median time of 121 days - a rate 4.6 per 100 person years - but community exposure could not be ruled out. Overall agreement between HCV - antibody and HCV - RNA assays was 86 % ( 100% in the HCV negative samples ) - kappa = 0.71.
Injecting history was highly prevalent in prison entrants ( 70 % ) and both community and prison injecting ( but not tattooing ) were independent predictors of entry HCV status. Prison history was also independently associated with entry HCV status. Injecting in prison during the study was infrequently reported, but significantly more likely in those testing HCV - antibody positive at prison entry ( risk ratio = 2.48, P = 0.046 ).
Stakeholders were most supportive of strategies to increase education and to minimise risks associated with hair clippers, but did not support most other suggested preventive strategies. Other issues related to communicable diseases and infection control were explored in the stakeholder interviews.
Conclusions:
HCV prevalence in South Australian prisoners is extremely high and may have contributed to a ' ceiling effect ' , minimising the seroconversion rate observed in this population. Injecting is relatively infrequently reported in prison, but more likely in those already infected with HCV. Thus, contaminated injecting equipment represents a significant threat to other prisoners and prison staff. Strategies aimed at reducing HCV risk in prisons, which address the concerns of those expected to implement them, are proposed in this thesis.Thesis (Ph.D.)--University of Adelaide, School of Population Health and Clinical Practice, 2006.
47
Chai-Jan, Chang, and 張家禎. "The Transmission Routes and Serum ALT Levels in Relation to Hepatitis C, Hepatitis B Virus Infection among Intravenous and non-Intravenous Drug Abusers." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/30139831611574721585.
Full textAbstract:
博士高雄醫學大學
醫學研究所
88
A seroepidemiology surrvey of anti-HCV, hepatitis B virus markers, and liver function among drug abusers in southern Taiwan was conducted. During the peroid from October 1994 to February 1996, a total of 935（899 males, 36 females）drug abusers from Kaohsiung Narcotic Abstention Institute and Kaohsiung Prison. The prevalence of anti-HCV antibody was 29.1% among male drug abusers and 19.4% among female drug abusers. The seroprevalence of anti-HCV antibody was 66.4% among intravenous drug abusers (IVDU) and 14.4% among non-intravenous drug abusers (non-IVDU). Intravenous drug use, a history of hepatits, having tattoos, and age were independently related to HCV seropositivity among drug abusers. The prevalence of anti-HCV antibody concentrations significantly increased (10.8-fold) with intravenous drug abuse and with having tattoos (1.7-fold). Among 247 intravenous male drug abusers, age and duration of drug use were independently related to HCV seropositivity. Seroprevalence rate for HCV in the IVDU group increased with increasing duration of injection use within the first seven years of drug use. However, the steepest trajectory in seroprevalence of HCV infection occurred within the first four months. According to univariate analysis in our study, the number of lifetime IVDU sex partners and frequency of condom use were found to be significantly associated with HCV infection, however, were not reached significantly in logistic regression analysis. Age was an indepentent risk factor of HCV infection, which was significantly associated with sexual behavior among the IV drug users. This would suggest that sexual transmission may still occur, albeit infrequently. The positive rates of HBsAg, anti-HBs, and anti-HBc were 21.2%, 70.2%, and 86.5%, respectively. The prevalence of HBV infection among intravenous drug abusers (96.8%) was significantly higher than among non-intravenous subjects (92.9%). In the pattern of combination of the three markers with 30 years of age as a border, the HBsAg(-), anti-HBs(+), anti-HBc(+) combination was more frequent under 29 years of age, however, the HBsAg(+), anti-HBs(-), anti-HBc(+) combination and all positive combination were more over 30 years of age. The frequency of HBV infection with serum anti-HBc negative was 8.4% among the intravenous drug abusers. Drug abusers with HBsAg or anti-HCV had higher serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels than those without HBsAg and anti-HCV. The pervalence of raised ALT and AST (>35 IU/L) in the HCV-positive group was more significant than in the negative group, while the HBsAg-positive group did not reach statistical significance. Among the HCV-positive group, ALT levels are more closely associated with HCV infection than AST levels. These findings suggest that hepatitis C virus may be mainly transmitted by the parenteral route among drug abusers in southern Taiwan. Due to the high rate of HCV infection among drug abusers, investigation of high-risk behavior should be routine in this group. To prevent HCV infection, emphasis on the use of sterile needles and aseptic procedures in tattooing is important in Taiwan. A high frequency of HCV infection was also found among short-term injectors, which indicated that early risk reduction intervention was an important measure in moderating HCV infection. Our findings suggest that horizontal transmission may be considered a possible reason for the significantly higher rate of HBV infection among intravenous drug abusers. Our sutdy also found that there may be an "immune incompetence" in intravenous drug abusers incapable of producing antibodies to hepatitis B core antigen. Due to the changes of combination of these three serum HBV markers and high prevalence rate of HBV infection among intravenous drug abuseres, investigation of serum HBV markers and liver function should be emphasized in these subjects. Our results indicated that HCV infection plays an important role in the etiology of raised ALT activity among drug abusers, while HBV infection plays a minor role. ALT screening still remains a simple and valuable method in the early recognition of HCV infection. The results of our study suggest that HCV superinfection in patients with chronic HBV infection may suppress or terminate the HBV carrier state among non-intravenous drug abusers. In addition, liver disease appeared to be more severe in patients with HCV infection alone than in patients with concurrent HBV and HCV infections. This means that a suppressive action between hepatitis B and C viruses may occur in dual infection with both viruses.
48
Curado, Ana Raquel Dias. "Management of hepatitis C virus infection : are children the same as adults?" Master's thesis, 2015. http://hdl.handle.net/10451/24844.
Full textAbstract:
Trabalho Final do Curso de Mestrado Integrado em Medicina, Faculdade de Medicina, Universidade de Lisboa, 2015A Hepatite C tornou-se um relevante problema de saúde pública. Cerca de 3% da população mundial está infectada, no entanto, a prevalência nas crianças é baixa. Distintamente dos adultos, em que a principal via de transmissão é o uso de drogas injectáveis, actualmente, na idade pediátrica, a transmissão vertical é a principal causa. Na sua maioria, as crianças infectadas pelo vírus da Hepatite C são assintomáticas e apresentam uma progressão geralmente lenta da doença. Ainda assim, alguns grupos seleccionados podem beneficiar de tratamento em idade pediátrica com interferão (IFN) alfa peguilado e ribavarina. A abordagem da Hepatite C na criança pode mudar drasticamente num futuro próximo com a introdução de regimes terapêuticos sem IFN, adequados à populacão pediátrica. Esta revisão tem como objectivo proporcionar informação actualizada sobre a abordagem da Hepatite C na idade pediátrica e perspectivar as diferenças desta infecção no adulto e na criança.
Hepatitis C virus (HCV) infection has become a public health issue. About 3% of the world’s population is affected by HCV. However, prevalence of HCV infection in children is low. Unlike adults, in which the main route of transmission is by intravenous drug use, the most common via of HCV infection in children is, currently, vertical transmission by HCV infected mothers. Nearly all of infected children are asymptomatic, showing a slowly progressive course of disease. Nevertheless, selected children may benefit from treatment with pegylated interferon (IFN)-alfa plus ribavirin. The possibility of IFN-free regiments, suitable for pediatric population, can drastically chance the management of HCV infection in children in the near future. The objective of this review is to provide updated information about the management of HCV infection in the pediatric age group, as well as the differences between the HCV infection in children and adults.
49
鳥居, ゆか, and Yuka Torii. "Causes of vertical transmission of hepatitis B virus under the at-risk prevention strategy in Japan." Thesis, 2014. http://hdl.handle.net/2237/20394.
Full text
50
Huang, Chi-Wen, and 黃琦文. "Prediction of Mother-to-Infant Transmission of Hepatitis B Virus Infection by Using Perinatal Maternal Serum Quantitative Surface Antigen." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/39592793970290129082.
Full textAbstract:
碩士國立臺灣大學
流行病學與預防醫學研究所
102
Background: To eliminate hepatitis B virus mother-to-infant transmission, it is necessary to detect pregnant women with high hepatitis B virus (HBV) DNA and then give additional prevention strategy before delivery. Quantitative Hepatitis B surface antigen (HBsAg) is a newly developed method with a unit price much lower than that of HBV DNA. We aimed to evaluate the correlation between quantitative HBsAg and HBV DNA and to assess the feasibility of quantitative HBsAg as a predictor in high risk screening. Methods: We conducted a prospective cohort study, 461 pairs of HBsAg positive mothers and their infants were enrolled. Serum HBsAg, HBeAg and HBV DNA level of these mothers were measured. Infants were followed up to 1-1.5 years old and had two separate serum HBsAg tests. Spearman’s correlation coefficient was used to examine the correlation between quantitative HBsAg and HBV DNA. Logistic regression analyses were used to assess the predictive ability of HBV DNA, quantitative HBsAg, and other risk factors of mother-to-infant transmission. Results: Among the 461 infants, 16 infants were found to be infected with HBV. All of them were born to HBeAg positive mothers with high HBV DNA (7.9±0.74 log10 IU/ml) and high quantitative HBsAg (4.7±0.2 log10 IU/ml). Quantitative HBsAg had a significant positive correlation with HBV DNA level (r=0.64, p<0.0001) in all subjects and in HBeAg positive subjects group (r=0.62 p<0.0001). The optimum cut-off point for HBV DNA concentration of 7 log10 IU/ml was 4.26 log10 IU/ml, with a sensitivity of 93%, specificity of 97%. After adjusting possible confounders, quantitative HBsAg could significantly predict mother-to-infant transmission. Conclusion: Our study documents that quantitative HBsAg is highly correlated with, and as predictive as HBV DNA for mother-to-infant transmission. With the concern of the screening cost, quantitative HBsAg may be used as a new screening tool during pregnancy.