Thesis (D.P.H.)--University of Alabama at Birmingham, 2008. / Title from first page of PDF file (viewed on June 25, 2009). Includes bibliographical references.

Thesis (Ph.D.)--University of Alabama at Birmingham, 2008. / Title from PDF title page (viewed on Sept. 17, 2009). Includes bibliographical references (p. 54-62).

p. 1-71 / Submitted by Santiago Fabio (fabio.ssantiago@hotmail.com) on 2013-04-23T20:07:08Z No. of bitstreams: 1 11111ee.pdf: 1402726 bytes, checksum: 47dcda030901a96f687080b863e3c5a0 (MD5) / Approved for entry into archive by Maria Creuza Silva(mariakreuza@yahoo.com.br) on 2013-05-04T17:25:32Z (GMT) No. of bitstreams: 1 11111ee.pdf: 1402726 bytes, checksum: 47dcda030901a96f687080b863e3c5a0 (MD5) / Made available in DSpace on 2013-05-04T17:25:32Z (GMT). No. of bitstreams: 1 11111ee.pdf: 1402726 bytes, checksum: 47dcda030901a96f687080b863e3c5a0 (MD5) Previous issue date: 2010 / Apesar de a peste encontrar-se silente em todo o território brasileiro, seu agente etiológico, a bactéria Yersinia Pestis, permanece firmemente arraigada em seus focos naturais. Desta forma, e tendo em vista a existência de fatores condicionantes, não se pode desconsiderar que a doença, apesar de controlada, continua oferecendo riscos à população. A ocorrência de sorologia positiva para peste em carnívoros domésticos de algumas regiões pestígenas da Bahia nos últimos anos implica na necessidade de uma avaliação mais criteriosa, no intuito de verificar se ainda existe circulação do bacilo pestoso nessas áreas. Analisou-se, neste estudo, a presença de infecção por Y. pestis através do inquérito de soroprevalência em humanos, cães e roedores; e detecção da bactéria em roedores e pool de pulgas. A partir da aplicação de um questionário estruturado avaliou-se a associação existente entre fatores ambientais, sócio-econômicos e biológicos e a soroprevalência da infecção em humanos. Os 630 soros examinados (88 de humanos, 480 de cães, 62 de roedores) apresentaram-se não-reagentes para peste e as análises bacteriológicas realizadas em 14 roedores e 2 pool de pulgas não identificaram a bactéria. No entanto, tais resultados não configuram erradicação da doença no Estado. A natureza cíclica da peste indica que ela pode passar por longos períodos de silêncio e depois ressurgir acometendo um grande número de pessoas. Portanto, a manutenção de uma vigilância ativa e permanente se faz necessária para a detecção precoce da doença e desenvolvimento oportuno das medidas de controle pertinentes. / Salvador

Made available in DSpace on 2014-06-11T19:27:57Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-02-26Bitstream added on 2014-06-13T18:32:17Z : No. of bitstreams: 1 santos_tr_me_jabo_prot.pdf: 615595 bytes, checksum: 5ebde41577462db0b3f3c42f920081d7 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Considerando a grande importância da toxoplasmose animal sobretudo em decorrência dos animais infectados servirem de fonte direta ou indireta de infecção ao homem, avaliou-se a freqüência de anticorpos anti-Toxoplasma gondii em bovinos leiteiros, complementando o estudo com amostras colhidas de caninos e humanos de convívio rural. Foram colhidas amostras de sangue de 200 fêmeas leiteiras bovinas, 61 cães e 116 humanos, pertencentes a 50 propriedades da região sudoeste do Estado do Mato Grosso. Os soros foram submetidos à reação de imunoflorescência indireta (IgG-RIFI), utilizando-se comomponto de corte as duluições de 1:64, 1:40 e 1:40 para bovinos, cães e humanos, respectivamente. Anticorpos para T. gondii foram encontrados em 71,00% dos bovinos (n=1420); 88,52% dos cães (n=54) e 97,41% dos humanos (n=113). As amostras de humanos também foram avaliadas para IgM, que mostrou 33,62% de soropositividade. Após essa triagem sorológica, as amostras positivas exceto de humanos, foram processadas até obtenção de título final. A associação dos riscos relacionados à toxoplasmose (IgG)como, consumo de leite cru, produção de derivados de origem animal, abate de animais e contato com felinos e/ou ouros animais, não influenciou na distribuição dos sororreagentes (P>=0,05). Contudo, em relação à presença de IgM detectou-se associação entre soropositividade e o abate de animais para o consumo próprio (P<=0,05). Os resultados demonstraram a elevada prevalência da infecção toxoplasmática na população estudada e o alto risco da carne como via de transmissão para o homem, quando manipulada ou ingerida crua ou mal cozida. / To determine the prevalence of anti-Toxoplasma gondii antibodies, 200 samples of blood serum from female dairy cattle belonging to 50 farms in the southwest of the state of Mato Grosso were analyzed by indirect immunofluorescent antibody test (IFAT>=40) for anti-T. Gondii. From these, 1420 (71,00%) of the cattle serum, 54 (88,52%) of the dog serum and 113 (97,41%) of the serum human were positive for the infection, at a diluition of 1:64 or more for cattle, 1:40 or more for dog and 1:40 for human. The samples human were also evaluated for IgM, wich showed 33,62% of seropositivity. No significant differences were observed to infection toxoplasmic (IgG) in terms consuption of raw milk, produce derivaties of animal origin, slaughtering of animals and contact with felines or other animals. However, for IgM was determined association between seropositivity and the slaughter of animals for personal consumption. Infection toxoplasmic has a high prevalence on the studied population. The results suggest that the handle or eat raw/rare cooked meat may be importants ways of transmiting toxoplasmosis to humans in this region.

Submitted by Claudia Rocha (claudia.rocha@udesc.br) on 2018-03-21T14:35:44Z No. of bitstreams: 1 PGCA17MA229.pdf: 654110 bytes, checksum: 5902ad01c6d4e8ebc529569a73b149aa (MD5) / Made available in DSpace on 2018-03-21T14:35:44Z (GMT). No. of bitstreams: 1 PGCA17MA229.pdf: 654110 bytes, checksum: 5902ad01c6d4e8ebc529569a73b149aa (MD5) Previous issue date: 2017-08-25 / Capes / Neosporosis is a disease that affects ruminants, horses, swine and wild animals, causing reproductive disorders and economic losses. The importance of infection in pigs has not yet been fully elucidated. The objective of the present study was to verify the prevalence of antibodies against Neospora caninum and the possible risk factors associated with infection in swine herds of commercial herds in the State of Santa Catarina, Brazil. A total of 498 blood samples were collected from western (five properties) and southern (four properties) regions and epidemiological questionnaire was used. After obtaining the serum, they were tested by means of the Indirect Immunofluorescence Reaction (IFAT), with a cut-off point of 1:50, using tachyzoites of the NC1 strain of the agent as antigen. The positive samples were diluted in multiples of two until the maximum reactive titre. The variables were analyzed using Fisher and Chi-square tests to verify correlation with seroprevalence. The overall prevalence was 18.9% (94/498), with a reciprocal distribution of the following: 27 (1:50), 26 (1: 100), 22 (1: 200), 10 (1: 400), 9 (1: 800). Of the 256 samples from the Western region, 80 (31.3%) were positive and 242 samples from the South region, 14 (5.8%), were positive. A significant statistical difference (p <0.01) was observed among the prevalences observed in the evaluated farms. Contact with dogs (OR= 3,97), presence of rodents (OR= 7,37), and water source (OR= 2,38) presented a positive statistical correlation (p <0.01) with seroprevalence. The use of anti-bird screen was identified as a protection factor for infection (OR= 0,36). The seroprevalence of antibodies against N. caninum in commercial swine herds in Santa Catarina was 18.9% (94/498), considered high in comparison with other results observed in Brazil / Neosporose é uma doença que acomete ruminantes, equinos, suínos e animais selvagens, causando transtornos reprodutivos e prejuízos econômicos. A importância da infecção em suínos ainda não está totalmente elucidada. O objetivo do presente trabalho foi verificar a prevalência de anticorpos contra Neospora caninum e os possíveis fatores de risco associados à infecção em matrizes suínas de rebanhos comerciais no Estado de Santa Catarina, Brasil. Foram colhidas 498 amostras de sangue em propriedades das regiões Oeste (cinco propriedades) e Sul do Estado (quatro propriedades) e aplicado questionário epidemiológico. Após a obtenção do soro, estes foram testados por meio da Reação de Imunofluorescência Indireta (RIFI), com ponto de corte de 1:50, utilizando taquizoítos da cepa NC1 do agente como antígeno. As amostras positivas foram diluídas em múltiplos de dois até a máxima titulação reativa. As variáveis foram analisadas por meio dos testes exato de Fisher e do Qui quadrado para verificar correlação com a soroprevalência. A prevalência geral foi de 18,9% (94/498), com recíproca de títulos distribuída da seguinte forma: 27 (1:50), 26 (1:100), 22 (1:200), 10 (1:400), 9 (1:800). Das 256 amostras da região Oeste, 80 (31,3%) foram positivas e das 242 amostras da região Sul, 14 (5,8%), foram positivas. Foi observada diferença estatística significativa (p<0,01) entre as prevalências observadas nas granjas avaliadas. Contato com cães (OR= 3,97), presença de roedores (OR= 7,37) e a fonte de água proveniente de “olho d´água” ou mina (OR= 2,38) apresentaram correlação estatística positiva (p<0,01) com a soroprevalência. A utilização de tela antiaves foi identificada como fator de proteção para a infecção (OR= 0,36). A soroprevalência de anticorpos contra N. caninum em rebanhos comerciais de matrizes suínas em Santa Catarina foi de 18,9% (94/498), considerada alta em comparação com outros resultados observados no Brasil

O HEV é um patógeno viral, transmitido principalmente pela via fecal-oral e responsável por grandes surtos de hepatite em todo o mundo. A hepatite E é considerada a hepatite com transmissão entérica mais frequente no mundo, e um importante problema de saúde pública. Por apresentar uma fase sanguínea assintomática e ser um agente emergente, cuja incidência vem aumentando ao longo da última década, o HEV é também considerado um problema para a hemoterapia, uma vez que põe em risco a segurança transfusional, devido ao risco de sua transmissão por transfusão sanguínea. No Brasil, sua ocorrência e características ainda não são compreendidas e os estudos disponíveis são limitados. Objetivo: Determinar a prevalência do HEV em doadores de sangue do Hemocentro de Ribeirão Preto no ano de 2015. Material e Métodos: Foram selecionados aleatoriamente 1.000 doadores de sangue do Hemocentro de Ribeirão Preto no período de janeiro a dezembro de 2015. Inicialmente, foi realizada a pesquisa de anticorpos da classe IgG do HEV em plasma, utilizando a metodologia de imuno-ensaio enzimático (ELISA). As amostras que se apresentaram reagentes (positivas ou inconclusivas) para IgG HEV, foram submetidas à pesquisa de antígenos virais, também por metodologia ELISA. Paralelamente aos testes sorológicos, foi realizado o teste molecular para a detecção de RNA viral, aplicando a técnica de PCR em tempo real e utilizando primers desenhados para a região mais conservada do vírus (ORF-3). Resultados: Entre as 1.000 amostras testadas, 124 foram positivas para a pesquisa de anticorpos anti-HEV IgG e 5 foram inconclusivas. A soroprevalência encontrada foi de 12,5%. A maior prevalência encontrada foi na faixa etária de 50-59 anos (21,2%, p<0,01), porém com aumento significativo entre os 40 e 69 anos de idade. A menor prevalência encontrada foi no grupo etário de 18 a 29 anos (3,9%). A soroprevalência foi proporcionalmente maior entre os indivíduos do gênero masculino (14,3%, p<0,06) em relação aos indivíduos do sexo feminino (10,4%). Nenhuma das amostras testadas foi positiva para a pesquisa de antígenos HEV e nem para a detecção de RNA viral. Conclusão: A soroprevalência do vírus da hepatite E encontrada entre os doadores de sangue de Ribeirão Preto foi alta (12,5%) e compatível com os dados nacionais de soroprevalência entre doadores. A viremia não pode ser estabelecida, pois não foram encontrados casos de HEV RNA positivos. / HEV is a viral pathogen, transmitted primarily by the fecal-oral route and responsible for large outbreaks of hepatitis worldwide. Hepatitis E is considered the most common transmissible enteric hepatitis in the world, and is currently considered a major public health problem. Because it presents an asymptomatic blood stage and is an emerging agent whose incidence has increased over the last decade, HEV is also considered a problem for hemotherapy, since it jeopardizes transfusion safety due to the risk of its transmission by transfusion. In Brazil its occurrence and characteristics are poorly understood and available studies are limited. Objective: To determine the prevalence of HEV in blood donors at the Hemocentro de Ribeirão Preto in the year 2015. Material and Methods: 1.000 blood donors were randomly selected from the Hemocentro of Ribeirão Preto from January to December 2015. Initially, a HEV IgG antibody was investigated in plasma, using ELISA (enzyme immunoassay). As samples that presented reagents (positive or inconclusive) for HEV IgG, they were submitted to the research of viral antigens, also by ELISA methodology. In parallel to the serological tests, it was carried out for molecular testing to detect viral RNA, applying a real-time PCR technique and using primers designed for a more conserved region of the virus (ORF-3). Results: Among 1,000 tested samples, 124 were positive for anti-HEV IgG antibodies and 5 were inconclusive. One seroprevalence was found to be 12.5%. A higher prevalence was found in the age range of 50-59 years (21.2%, p<0,001), but with a significant increase between 40 and 69 years of age. The lowest prevalence was found for the 18-29 age group (3.9%). Seroprevalence was proportionally higher among males (14.3%, p<0,06) than among female users (10.4%). It was not evaluated for a HEV antigen search or for viral RNA detection. Conclusion: A seroprevalence of hepatitis E virus found among blood donors from Ribeirão Preto and high (12.5%) and compatible with data from seroprevalence among donors. Viremia cannot be established because no cases of positive RNA HEV have been found

IntroductionLa drépanocytose est l’affection génétique la plus répandue dans le monde plus particulièrement en Afrique subsaharienne, considérée à juste titre comme l’une des régions originaires de la mutation drépanocytaire avec de fortes prévalences. Elle est reconnue comme un problème de santé majeur par la communauté internationale en raison de sa morbidité et de sa mortalité élevées. Au Mali, environ 5 à 6 milles naissances de drépanocytaires sont enregistrées par an [Diallo, 2008] et ils auront besoin d’une prise en charge médicale spécifique. Le Centre de Recherche et de Lutte contre la Drépanocytose (CRLD) situé à Bamako est le seul centre de traitement spécifique dédié à la lutte contre la drépanocytose au Mali. Il reçoit des patients drépanocytaires du Mali et de la sous région. Ces patients sont pour la plupart vus au stade de complications puisqu’il n’existe pas de programme de dépistage systématique dès la naissance et à fortiori de suivi.La transfusion sanguine intervient dans une large mesure pour la prise en charge thérapeutique de ces patients. Acte thérapeutique essentiel sur le continent Africain en raison de la fréquence d’anémies de diverses origines (certaines nécessiteront un traitement de la cause).Cette transfusion sanguine comporte des risques non négligeables en Afrique, notamment dans le domaine des agents transmissibles par le sang. Un dépistage systématique des infections par le virus de l’immunodéficience humaine (VIH), le virus de l’hépatite C (VHC), le virus de l’hépatite B (VHB) et le tréponème, agent de la syphilis, est en vigueur sur tous les dons de sang à Bamako, mais les prévalences élevées de ces agents infectieux dans la population générale dont sont issus les donneurs de sang incitent à penser que le risque transfusionnel résiduel doit être important. Dans le but de renforcer la sécurité transfusionnelle au Mali, nous avons entrepris des études prospectives et rétrospectives chez les donneurs de sang et chez les drépanocytaires transfusés, ceci afin d’identifier les problèmes spécifiques liés à la thérapeutique transfusionnelle chez les drépanocytaires et de proposer une meilleure stratégie pour leur prise en charge.Méthodologie :Nous avons conduit une série d’études, visant à déterminer :- les caractéristiques des donneurs, des dons de sang et de l’organisation des centres de transfusion en Afrique subsaharienne francophone ;- la séroprévalence des agents infectieux transfusionnels majeurs (VIH, VHB, VHC) pour les dons de sang effectués au CNTS du Mali et chez les patients drépanocytaires recrutés au CRLD. - la fréquence de l’allo-immunisation anti-érythrocytaire avant et après la transfusion sanguine chez les drépanocytaires.- identifier les problèmes liés au dépistage néonatal et au suivi des drépanocytaires dépistés au Mali.Les donneurs de sang (volontaires et familiaux) ont été inclus selon les critères du don en vigueur au Mali. Le diagnostic de la drépanocytose a été réalisé par une technique de chromatographie liquide à haute performance (CLHP) avant inclusion des patients.Le dépistage des infections virales a été effectué par une méthode immunoenzymatique (ELISA) et la recherche des anticorps anti-érythrocytaire par un test de Coombs indirect.Résultats :Dans les sept pays, les donneurs de la tranche d’âge 18 à 30 ans étaient les plus nombreux, représentant plus de 45 % dans tous les centres, et plus de 70%dans quatre centres sur sept. Les donneurs masculins étaient les plus nombreux (plus de 70% de l’ensemble). Les donneurs étaient majoritairement volontaires (plus de 70 %), sauf au Cameroun et au Mali où ils représentaient respectivement 25,5 et 30 %. Quatre pays, dont ces deux derniers, avaient moins de 50 % de donneurs réguliers.Sur un total de 25 543 dons de sang recueillis au CNTS de Bamako en 2007, les séroprévalences des agents infectieux dépistés étaient de :2,6 % pour le VIH; 3,3 % pour le VHC et 13,9 % pour le VHB. En fonction du type de don, il y’avait une différence statistiquement significative (p <0,05) entre ces séroprévalences et plus élevées chez les donneurs familiaux que chez les donneurs volontaires bénévoles.Chez les 133 drépanocytaires transfusés au moment de leur inclusion dans l’étude, les séroprévalences des infections virales observées étaient de :1%, 3% et 1% respectivement pour les VIH, VHB et VHC. Trois cas de séroconversion post-transfusionnelle ont été observés. Tous avaient reçu du sang de donneurs familiaux. L’allo-immunisation anti-érythrocytaire était observée chez 4,4% (4/90) des drépanocytaires avec antécédents transfusionnels au moment de leur inclusion; les anticorps observés étaient de type anti D (un cas), anti C (deux cas) et un anti c (un cas). Elle n’a été observée chez aucun patient drépanocytaire ayant reçu leur 1ère transfusion au CRLD, avec exclusivement des concentrés de globules rouges phénotypés.Concernant le dépistage néo-natal de la drépanocytose, sur un total de 2480 nouveau-nés dépistés, 16 étaient atteints de l’affection. Aucun suivi médical programmé n’a pu être réalisé.Conclusion :Les prévalences relativement élevées des agents infectieux dans les dons de sang effectués par des donneurs familiaux majoritaires et les séroconversions observées après transfusion sanguine, justifient une politique de sécurisation des procédures de transfusions chez les drépanocytaires basée notamment sur le recrutement de donneurs volontaires.L’amélioration de la survie des patients drépanocytaires passe par la mise en place de programmes de dépistage précoce et de suivi régulier, mais si cette stratégie est réalisable du point de vue du diagnostic, il n’en demeure pas moins qu’elle soulève des problèmes de financement de cette activité et de sa pérennisation ;ces aspects doivent faire l’objet de réflexions pour une solution à long terme. / Introduction Sickle cell disease is the most common genetic disorder in the world, especially in sub-Saharan Africa where sickle cell mutation with high prevalence’s is originated high. It is recognized as a major health problem by the international community due to its morbidity and mortality. In Mali, around 5-6000 newborns annually affected by sickle cell disease [Diallo, 2008] and they will require specific medical that is by the “Centre de Recherche et de Lutte contre la Drépanocytose » (CRLD) in Bamako. This is the unique Malian center where sickle cell patients from Mali and the sub-region are treated. Because of the lack of systematic screening program at birth, most of the patients are seen at the stage of complications. Blood transfusion is largely used for therapeutic management of these patients. It constitutes an essential therapeutic approach against anemia of highly prevalent in Africa various origins (some requiring also treatment of the cause). However, blood transfusion means significant risks, particularly in area of high prevalence of transfusion transmissible infectious agents. A systematic screening for viral infections like human immunodeficiency virus (HIV), hepatitis C virus (HCV), hepatitis B virus(HBV) and Treponema agent of syphilis is required for all blood donations in Bamako, but the high prevalence of these infectious agents in the general population, i.e. blood donors, suggest that the residual risk of transfusion must be important.In order to enhance blood transfusion safety in Mali, we undertook prospective and retrospective studies in the population of blood donor and sickle cell patient transfused to identify transfusion related adverse events and especially for SCD’ patients, suggest a better strategy for their follow-up. Methodology:We conducted a sery of studies which aims to determine:- The characteristics of donors, blood donation and the organization of blood transfusion centers in sub-Saharan French speaking Africa;- The seroprevalence of major infectious agents (HIV, HBV, and HCV) in blood donations at the CNTS in Mali and in sickle cell patients at CRLD. The frequency of anti-erythrocyte allo immunization before and after blood transfusion in sickle cell disease patients;- Identification of difficulties related to newborn screening and monitoring of sickle cell patients in Mali.Blood donors (volunteers and family) were included according to the criteria of blood donation in Mali.Hemoglobin type in sickle cell was determined by the technique of high performance liquid chromatography (HPLC) before patients’ inclusionScreening for viral infections was performed by enzyme immunoassay (ELISA) and the search for anti-erythrocyte antibodies by indirect Coombs test. ResultsIn the seven countries, donors aged from 18 to 30 years old were more represented i.e. 45% in all centers and more than 70%in four of the seven centers. More than 70% of blood donors were males. Donors were mostly volunteers (over 70%), except in Cameroon and Mali accounting for25.5% and30%, respectively four countries, including Cameroon and Mali had less than,50% of regulars donors.Of the 25 543 blood donations collected at the CNTS in Bamako in 2007, seroprevalence of infectious agents detected represented: 2.6%, 3.3%, and 13.9% for HIV, HCV, and HBV respectively. A statistical significative difference (p<0.05) was observed between family and volunteer donors in term of seroprevalence.the 133 sickle cell patients who received blood transfusion at inclusion, the seroprevalence of viral infections was1%, 3%, and 1%,for HIV, HBV, and HCV, respectively. Three cases of post-transfusion seroconversion were observed but only in sickle cell patients who received blood from family donors.Anti-erythrocyte alloimmunization was observed in 4.4% (4/90) among sickle cell patients with blood transfusion history at the time of inclusion; observed antibodies were anti type D (one case), anti C (two cases) and anti c (one case). However, no case was observed in any sickle cell patients, who received phenotyped RBC at CRLD,For neonatal screening, among the 2480 newborns, 16 were affected. However no scheduled medical follow-up was realized. Conclusion The relatively high prevalence’s of infectious agents in family donors, who represented the majority of blood donors, and of seroconversion observed after blood transfusion in sickle cell patients justify a security policy of blood transfusion procedures based, particulary for SCD patients, blood donations by volunteers. Improved survival of patients with sickle cell disease should be based on the development of early detection programs and regular monitoring. However if this strategy is feasible in terms of diagnosis ,it raises problems at funding for this activity and also of; those should be the subject of discussion for a long term solution / Doctorat en Sciences biomédicales et pharmaceutiques (Médecine) / info:eu-repo/semantics/nonPublished

Toxoplasma gondii est un parasite intracellulaire obligatoire. L'infection par T. gondii est largement répandue dans le monde entier. Néanmoins, elle est peu étudiée dans les pays d'Asie du Sud-est dont la Thaïlande.Nous avons réalisé 3 travaux sur le terrain en Thaïlande pour essayer de comprendre la circulation de ce parasite à travers une étude de séroprévalence chez des poulets en zone rurale et des essais d’isolement de souches chez les animaux en vue d’un génotypage. Lors des deux premières missions de terrain dans deux villages de la province de Kanchanaburi, nous avons cherché à déterminer la séroprévalence de l’infection chez des poulets (Gallus domesticus) en utilisant 2 tests sérologiques, Modified-Agglutination Test (MAT et immunofluorescence indirecte (IFAT) puis à isoler des souches de T.gondii à partir des animaux séropositifs. Lors de la troisième mission réalisée dans 3 autres provinces thaïlandaises(Nakhonratchasima, Lopburi et Saraburi), nous avons essayé d’isoler directement le parasite à partir de carcasses de poulets vendues sur les marchés ou d’autres animaux trouvés morts.La séroprévalence globale pour les 2 premières misions sur 600 poulets du Kanchanaburi était de 17,7% (IC 95% :14,6-20,7) et 33,0% (IC 95% : 29,2-36,8), par MAT et IFAT respectivement. Le calcul du coefficient κ montre une absence de concordance entre les deux tests.Au total, 162 essais d'isolement ont été effectués par inoculation à des souris, mais aucune souche viable de T. gondii n'a été isolée pendant ces 3 travaux sur le terrain. Cependant, nous avons détecté la présence d’ADN toxoplasmique en qPCR ciblant le gène 529 bp dans 13 culots de digestion d’organes de poulets, pigeon, caille et dans des cerveaux ou coeurs de souris inoculés par 16 autres poulets. Les Ct observés en qPCR étaient ≥33 indiquant une faible quantité d’ADN parasitaire dans nos échantillons qui n’a pas permis une caractérisation génétique par marqueurs microsatellites.Ce travail a démontré l'importance et les difficultés du travail de terrain pour l'étude de séroprévalence ainsi que l'étude d'isolement. L'isolement des souches de T. gondii a demandé un travail d'échantillonnage intensif, complexe dans l’environnement tropical et humide de la Thaïlande. Les différents paramètres ayant pu avoir un impact négatif sur nos résultats sont discutés. Ils expliquent l’absence d’isolement de souches chez des animaux séropositifs. / Toxoplasma gondii is an obligate intracellular parasite. Toxoplasma gondii infection is widespread throughout the world. Nevertheless, it is poorly studied in Southeast Asian countries including Thailand. We carried out 3 field works in Thailand to try to understand the circulation of T. gondii through a seroprevalence study in chickens in rural areas and strain isolation attempts in animals. During the two first field works, performed in Kanchanaburi province, we determined the seroprevalence in chickens (Gallus domesticus) using 2 serological tests, a Modified-Agglutination-Test (MAT) and an immunofluorescence assay (IFAT) and subsequently tried to isolate the strains of T. gondii from seropositive animals. During the third field work carried out in 3 other Thai provinces (Nakhonratchasima,Lopburi and Saraburi), we attempted to isolate strains directly from chicken carcasses sold in different markets or other dead animals.The overall seroprevalence for 600 chickens sampled over the two field works in Kanchanaburi was 17.7% (95%CI: 14.6% -20.7) and 33.0% (95% CI: 29.2-36.8), by MAT, and IFAT, respectively. The κ coefficient indicated an absence of concordance between the 2 serological tests.A total of 162 isolation attempts were performed by mouse bioassays, but no viable strain of T. gondii was isolated during these 3 field works. However, a qPCR targeting 529 bp T. gondii gene was positive for 13 digestion pellets of organs of chickens, pigeon, quail and in brains or hearts of mice inoculated with 16 other chickens. These qPCR were weaklly positive (Ct ≥33) indicating a low amount of parasite DNA in our samples that did not allow genotyping T. gondii with microsatellite markers.This work demonstrated the importance and difficulties of field work for the seroprevalence study as well as strain isolation. The isolation of T. gondii strains required intensive and complex sampling in the tropical and humid environment of Thailand. The diverse factors that could have a negative impact on our results are discussed. They might explain the absence of strain isolation from seropositive animals.

Human papillomaviruses (HPV) are double-stranded, DNA, epitheliotropic viruses that infect skin and mucosal membranes. Over 200 types of HPV have been identified and classified into alpha (α), beta (β), gamma (γ), mu (µ), and nu (ν) genera. HPV in the genus α mainly infect mucosal membranes, cause the majority of the ano-genital cancers, and are widely studied. However, epidemiology of HPV in the other genera, which mainly infect skin, is poorly understood. Few studies have reported the seroprevalence of cutaneous HPV among healthy individuals, and to date, no study has prospectively examined the association between cutaneous HPV seropositivity and development of external genital lesions (EGLs) in men. The objectives of this study were to estimate the seroprevalence of cutaneous HPV types and investigate factors associated with the seropositivity, and evaluate the association between seropositivity to cutaneous HPV types and the risk of development of EGLs. Several studies have reported the seroprevalence of mucosal HPV types (6, 11, 16 and 18) in the 4-valent HPV vaccine among men. However, few studies have reported the seroprevalence of the five additional HPV types (31, 33, 45, 52 and 58) in the recently approved 9-valent HPV (9vHPV) vaccine specifically among men across a broad age range. Baseline data on seroprevalence prior to vaccine introduction and dissemination are needed to establish the effectiveness of vaccines over time. Also, this study estimated the seroprevalence of 9vHPV vaccine types and investigated factors associated with the seropositivity among men residing in Brazil, Mexico, and the United States (U.S.). To estimate the seroprevalence of cutaneous HPV types and 9vHPV vaccine types, 600 men were randomly selected from the HPV Infection in Men (HIM) Study. To examine the association between seropositivity to cutaneous HPV types and development of EGLs, a case-control study of 163 incident EGL cases and 352 EGL-free controls nested in the HIM cohort was conducted. Cases were ascertained through visual inspection at each of up to 10 biannual clinical visits, confirmed through biopsy, and categorized into condyloma, suggestive of condyloma, penile intraepithelial neoplasia (PeIN) and other EGLs. Archived serum specimens were tested for antibodies against 14 cutaneous HPV types, β types (5, 8, 12, 14, 17, 22, 23, 24, 38 and 47), α type 27, γ type 4, µ type1 and ν type 41, and 9vHP types (6, 11, 16, 18, 31, 33, 45, 52 and 58) using a glutathione S-transferase (GST) L1-based multiplex serology assay. Socio-demographic and sexual behavior data were collected through a questionnaire. Binomial proportions were used to estimate seroprevalence, and logistic regression was used to examine factors associated with seropositivity. Overall, seroprevalence of ≥1 cutaneous HPV types was 65.4%, 1≥ β-HPV types was 39.0%, α-HPV 27 was 8.9%, γ-HPV 4 was 30.9%, µ-HPV 1 was 28.6%, and ν-HPV 41was 9.4%. Higher educational attainment was significantly associated with seropositivity to ≥1 cutaneous HPV types (adjusted odds ratio [AOR] 1.75 for ≥16 years of education vs. ≤12 years of education, 95% confidence interval [CI] 1.08-2.83), and seropositivity of ≥1 β-HPV types was significantly associated with increasing age (AOR 1.72 for men aged 31-44 years vs. men aged 18-30 years, 95% CI: 1.12–2.63,). Country of residence, circumcision status, and lifetime number of male anal sex partners were other factors significantly associated with various type-specific cutaneous HPV seropositivity. No statistically significant association was observed between grouped or individual cutaneous HPV seropositivity and the risk of development of EGLs across all pathological diagnoses. The seroprevalence of grouped and individual cutaneous HPV types was similar across different EGL categories and controls, with the most frequent types being ɤ-HPV 4, µ-HPV 1, and β-HPV 8. The seroprevalence of ≥1 9vHPV vaccine types was 28.3%, ≥1 high-risk types was 14.0%, five additional high-risk types was 11.2%, and low-risk types (6/11) was 17.4%. Compared to men with no male anal sex partners, men with ≥2 partners were two times more likely to be seropositive for grouped 9vHPV vaccine types, ≥1 high-risk types and ≥1 low-risk types, in addition to individual HPV types 6, 16, 33, and 58, with AORs ranging from 2.19 to 7.36. Older age, current smoking, and being single were other factors significantly positively associated with different grouped and type-specific seropositivity. In conclusion, our data show that exposure to cutaneous HPV was common in men although different risk factors were independently associated with grouped and type-specific cutaneous HPV seropositivity. It appears that exposure to cutaneous HPV is not likely to increase the risk of EGLs among men. Similarly, exposure to 9vHPV vaccine types was also common in men and seropositivity to 9vHPV vaccine types was positively associated with older age and lifetime number male anal sex partners.

La République du Congo (RC) ou nos travaux ont eu lieu, est un pays d’Afrique Centrale, il partage ses frontières avec la République démocratique du Congo, la République centrafricaine, le Gabon, le Cameroun, et l’Angola (Cabinda). Dans ces pays la circulation des arboviroses est documentée. En RC, il y avait peu ou pas de documentation sur les arboviroses avant nos travaux. Nous avons réalisé des études de séroprévalence des arboviroses de différentes familles chez des donneurs de sang Congolais. Nous avons aussi étudié l’épidémie de chikungunya ayant sévit en RC en 2011. Nos travaux ont permis de mettre en évidence des taux de séroprévalence élevés pour les pathogènes principaux incriminés: 47,2% pour Dengue, 27,8% pour Yellow fever, 24,4% pour West Nile, 38,8% pour Chikungunya et 7,9% pour Rift Valley fever. Ces taux de séroprévalence élevés prouvent la circulation de ces virus au Congo, bien qu’aucune épidémie n’ait été encore déclarée pour certains. Nous avons également isolé et caractérisé génétiquement une souche nommée "Brazza_MRS1", appartenant au lignage East Central and Southern African, issue de l’épidémie due au virus chikungunya de 2011. La RC a connu plusieurs épidémies dues au virus Ebola. Nous avons tenté de mieux caractériser la circulation des filovirus chez les donneurs de sang asymptomatiques par une étude de séroprévalence. Les taux de séroprévalence IgG anti Ebola virus, observés étaient de 2,5% en général (1,6% à Brazzaville, 4% à Pointe-Noire et 4% en milieux ruraux). Les facteurs de risques identifiés étaient l’exposition aux chauves-souris (p<0.001) et aux oiseaux (p = 0.04). Le taux de séroprévalence IgG anti Marburg virus était de 0,5%. / The Republic of Congo (RC) where our work took place is a Central African country, sharing borders with the Democratic Republic of Congo, Central African Republic, Gabon, Cameroon, and Angola (Cabinda). In these countries the circulation of arboviruses is documented. In RC, there was little or no documentation on arboviruses prior to our work. We conducted studies of arbovirus seroprevalence in Congolese blood donors for different virus families. We also studied the epidemic caused by the chikungunya virus that prevailed in RC in 2011.Our work have highlighted the high rate of seroprevalence for incriminated major pathogens: 47.2% for Dengue, 27.8% for Yellow Fever, 24.4% for West Nile, 38.8% for Chikungunya and 7.9% for Rift Valley fever. These high seroprevalence rates indicate that these viruses actively circulate in Congo, although no epidemic has yet been reported for some viruses. We have also isolated and genetically characterized a strain named "Brazza_MRS1", belonging to the East Central and Southern African lineage, after the chikungunya epidemic in 2011. The RC has experienced several outbreaks caused by the Ebola virus. We have performed a filovirus seroprevalence study to attempt to better characterize the circulation of filoviruses in asymptomatic Congolese blood donors. The observed rate of seroprevalence of anti Ebola IgG was 2.5% overall (1.6% in Brazzaville, 4% in Pointe-Noire and 4% in rural areas). Identified epidemiological risk factors were the exposure to bats (p <0.001) and birds (p = 0.04). The seroprevalence rate of Marburg virus IgG was low (0.5%).