• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 41
  • 25
  • 2
  • 2
  • 1
  • 1
  • Tagged with
  • 79
  • 22
  • 18
  • 18
  • 12
  • 11
  • 10
  • 10
  • 9
  • 8
  • 8
  • 7
  • 7
  • 7
  • 7
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Pequenos mamíferos em paisagens fragmentadas do estado do Rio de Janeiro e implicações na transmissão de Hantavírus

Oliveira, Jonathan Gonçalves de January 2014 (has links)
Made available in DSpace on 2016-01-07T13:41:42Z (GMT). No. of bitstreams: 2 jonathan_oliveira_ioc_mest_2014.pdf: 2250142 bytes, checksum: 1ef72016a6815c4200fb3797c82d3e75 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2015-04-14 / Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ, Brasil / A Mata Atlântica é um dos biomas de maior biodiversidade e um dos mais ameaçados, principalmente pelo processo de fragmentação florestal. Roedores e marsupiais formam o grupo mais diversificado dentre os mamíferos e exercem influência no dinamismo de florestas neotropicais, sendo bons indicadores de alterações na paisagem. Além disso, este grupo é de grande interesse para saúde humana, pois diversas espécies estão envolvidas em ciclos zoonóticos. Os roedores em particular, são hospedeiros específicos dos hantavírus, e o acompanhamento do seu ciclo de transmissão em áreas silenciosas para hantavirose contribui para estudos epidemiológicos sobre a doença. Os objetivos desse estudo foram: a) levantar a fauna de pequenos mamíferos de áreas fragmentadas de Mata Atlântica predominantemente na região noroeste fluminense; b) identificar os indivíduos por taxonomia integrativa; c) avaliar a influência de variáveis geográficas e de habitat na composição de espécies; d) avaliar a infecção por hantavírus nos roedores capturados e a preferência de habitat das espécies infectadas. Foram capturados 128 roedores e 81 marsupiais em 11 fragmentos florestais e em áreas de matriz alterada nos municípios de Cambuci, Miracema, Sumidouro e Varre-sai A identificação taxonômica dos animais capturados foi feita por morfologia externa, cariotipagem e análises moleculares para os gêneros Trinomys, Calomys, Oligoryzomys e Akodon. A composição de espécies foi relacionada ao tamanho, forma e grau de isolamento dos fragmentos florestais, distância entre fragmentos e também a características do habitat (complexidade e heterogeneidade) por regressão múltipla de matrizes de similaridade. A similaridade na composição de espécies nos fragmentos e nos municípios foi então avaliada por dendrogramas de dissimilaridade. As amostras sorológicas dos roedores capturados foram submetidas ao teste imunoenzimático (ELISA) para detectar a infecção por hantavírus. A preferência do hábitat da única espécie sororreativa para infecção por hantavírus (Akodon 2 cursor) foi avaliada por modelo linear generalizado utilizando as variáveis de habitat (os três primeiros componentes de uma análise de componentes principais) como variáveis independentes e a abundância de A. cursor nas estações de captura como variável dependente. A composição de espécies de pequenos mamíferos não foi influenciada pelos descritores geográficos e de hábitat. No dendrograma gerado pela similaridade na composição de espécies nos fragmentos observou-se que fragmentos que continham apenas espécies mais generalistas agruparam-se separadamente dos que continham ao menos uma espécie especialista Similarmente, paisagens amostradas que eram mais conservadas agruparam-se separadamente daquelas mais perturbadas. Akodon cursor, única espécie sororreativa, prefere áreas com dossel mais aberto e mais baixo, com sub-bosques abertos e com mais caules herbáceos e lenhosos, mostrando que esta espécie está adaptada a ambientes alterados. A ocorrência de circulação de hantavírus neste roedor e sua preferência por habitat alterado,sinaliza a importância da continuidade nos estudos sobre a circulação de hantavírus no estado do Rio de Janeiro, especialmente em áreas estudadas onde a paisagem encontra-se fragmentada e composta por espécies em sua maioria generalistas / he Atlantic rainf orest is one of the species’ richest biomes and one of the most threate ned, mainly by forest fragmentation. Marsupials and rodents are most diverse group among the mammals and influence the dynamics of N eotropical forests, being g reat indicators of landscape changes. Furthermore, this group is important to human health,becaus e s ome species are involved in zoonotic cycles . Some rodents , in particular , ar e specific hosts for hantaviru s; the monitoring of such species and the parasite transmission cycle in silent areas for hantavirus contributes to epidemiolog ical studies of the disease. The objectives of this study were: a) to perform an inventory of sm all mammal s in fragmented A tlantic f orest areas predominantly in the northwest region of the Rio de Janeiro state ; b) to identify specimens by integrative taxonomy; c) to evaluate the influence of geographic variables and habitat characteristics in species composition; d) to evaluate the hantavirus infection in rodents and to investigate habitat preference of the infected species. T he captured animals were identified by external mo rphology, karyotyp e and molecular analy s es for the genus Trinomys , Calomys , Akodon and Oligoryzomys . The influence of fragment size, shape and degree of isolation , distance between fragmentsand habitat features (complexity and heterogeneity) on species com position was tested using a multiple regression of dissimilarity matrices . S pecies composition in fragments and fragmented landscapes as a whole was then evaluated by cluster analysis using Jaccard similarity index and Wad’s method of linkage . The serum sa mples of rodents were subjected to enzyme - linked immuno no sorbent assay (ELISA) to detect hantavirus infection. The habitat preference of Akodon cursor (the only species infected with hantavirus) was tested by generalized linear model with habitat features (the first three principal components of a Principal Component Analysis) as independent variables and A. cursor abundance in capture stations as the dependent variable . We obtained 128 rodents and 81 marsupials captured in 11 forest fragments and areas in the disturbed matrix in the municipalities of Cambuci, Miracema, Sumidouro e Varre - sai . The species composition of small mammals was not influenced by any geographic and habitat descriptors. In the dendrogram generated by the similarity in species composit ion in fragments , we observed t hat fragments containing only generalist species w ere clustered separately from those that had at least one specialist species. Similarly, conserved landscapes clustered separately from disturbed ones . A kodon cursor prefer red areas with more open and low canopy height, with open understory , more herbaceous cover and woody stems, showing that this species is adapted to disturbed habitats. The oc currence of hantavirus circulation in this rodent and its preference for altered hab itat, signals the importance of monitoring studies about the this zoonosis in the s tate of Rio de Janeiro, especially in areas where the landscape is fragmented and composed of generalist species
52

Fatores de risco e de predição para infecções por arbovírus e hantavírus em famílias de áreas de reserva ecológica no Vale do Ribeira, SP / Risk factors and prediction for hantavirus and arbovirus infection in families of areas of ecological reserves in the Ribeira Valley, SP

Nicolina Silvana Romano Lieber 09 April 1996 (has links)
Realizou-se estudo analitico transversal relacionando caracteristicas individuais e familiares de 182 moradores pertencentes a 58 famílias de área de reserva ecológica à presença de infecções por arbovirus e hantavirus de interesse sanitário local. Pesquisou-se anticorpos para os antigenos dos virus Rocio, Ilhéus, da encefalite de st. Louis, das encefalites equinas do leste, oeste e venezuelana e Hantaan. Foram utilizados os testes de inibição de hemaglutinação, neutralização com redução de placas, imunofluorescência indireta e ensaio imunoenzimático com captura de anticorpos IgM (MAC-ELISA).· A associação estatistica foi pesquisada utilizando-se o teste de qui-quadrado e o grau de associação foi obtido calculando-se o odds ratio. Também foram pesquisadas a sensibilidade, a especificidade e os valores preditivos positivo e negativo das caracteristicas investigadas para avaliar seu poder de discriminar infectados de não infectados e de predizer infecções por arbovirus e hantavirus. A prevalência observada de anticorpos para arbovirus nos individuos foi de 26,9% e nas familias foi de 62,1%. Observou-se uma prevalência de 1,6% de anticorpos para hantavirus nos individuos e 5,2% nas familias. Não foram encontrados anticorpos para o virus da encefalite equina do oeste e nem anticorpos da classe IgM para os antigenos testados. Entre as caracteristicas estudadas, a idade, a ocupação, a naturalidade e o hábito de entrar na mata mostraram-se fatores de risco para infecções por arbovirus. Foram considerados fatores preditivos de infecção por arbovirus a presença de galinheiro anexo à casa, o hábito de criar galinhas e a presença de ratos no domicilio. Não foram observados fatores de risco ou de predição para infecção por hantavirus entre as caracteristicas estudadas. Os resultados obtidos sugerem que as caracteristicas, que mostraram ser fator de risco ou predição, poderiam ser usadas no diagnostico presuntivo preliminar de infecções por arbovirus e hantavirus, permitindo priorizar medidas de intervenção. O uso de um questionário ofereceria aos serviços de saúde ferramenta de simples aplicação e baixo custo, especialmente em condições de campo em áreas que, como a estudada, dispõe de escassos recursos humanos e laboratoriais. / In order to identify risk factors and predictive factors to arbovirus and hantavirus infections among individual and family characteristics, a cross-sectional study was carried out among 182 persons belonging to 58 families living at ecological reserve. The characteristics were associated with the presence of antibodies to the following virus of local interest: Hantaan, Rocio, Ilheus, Eastern, Western and Venezuelan equine encephalitis virus and st. Louis encephalitis virus using inhibition hemagglutination test, plaque reduction neutralization test, indirect immunofluorescence test and immunoglobulin M antibody capture enzyme immunoassay (MAC-ELISA). The associations were calculated using chi-square statistics and the odds ratio. Sensitivity, especificity, positive and negative predictive values of the individual and familiar characteristics were also analyzed to evaluate their capacity to discriminate between infected and non-infected people and to predict arbovirus and hantavirus infections. The prevalence of antibodies to arbovirus was 26.9% and 62.1% of the families had at least one member infected by these agents. Hantavirus antibodies were found in 1.6% of the sera analysed and 5.2% of the families had members infected by these agents. Antibodies to western equine encephalitis virus were not found. IgM antibodies were not observed sugesting no recent infection for those agents in that population. Age, ocupation, nativity and the habit to enter the forest were shown to be risk factors to arbovirus infections. The presence of annexes to the house, to breed chickens and the presence of rodents inside the house were considered predictive factors to arbovirus infections. Risk or predictive factors to hantavirus infections were not observed. The results suggest the use of some of the individual or family characteristics as a tool on the surveillance of arbovirus infections, to discriminate people with major probability of infections, specially in fie1d conditions, where human and laboratorial resources are scarce.
53

Estudo evolutivo dos hantavírus e desenvolvimento de uma RT-PCR quantitativa em tempo real para detecção do vírus Araraquara / Evolutionary study of Hantavirus and development of a quantitative real time RT-PCR for detection of Araraquara virus

William Marciel de Souza 28 March 2013 (has links)
O gênero Hantavírus está incluído na família Bunyaviridae que são vírus emergentes associados a roedores que podem infectar o homem causando graves doenças. Nas Américas, os Hantavírus causam uma síndrome pulmonar e cardiovascular (SPCVH) com alta letalidade. Cerca de 1600 casos de SPCVH já foram notificados no Brasil causando mais de 600 óbitos. Sete espécies de Hantavírus são conhecidas no Brasil incluindo o vírus Araraquara que circula nas regiões de cerrado do país associado ao roedor Necromys lasiurus. Para o desenvolvimento de uma RT-PCR em tempo real para detecção e quantificação de Hantavírus, mostramos as etapas para o desenvolvimento de uma one-step RT-PCR em tempo real SYBR Green I para Hantavírus Araraquara que se mostrou específica para o gênero e capaz de detectar até 10 cópias por mL de RNA viral na amostra. Além disso, realizamos um estudo filogenético utilizando algoritmos bayesianos, com 190 sequências completas do gene da nucleoproteína, oriundas de 30 países durante um período de 25 anos (1985-2010) que encontravam-se disponíveis no GenBank (NCBI). Baseando-se em uma taxa média de 6.8 x 10-4 (2.5 x 10-4 - 1 x 10-3) substituições nucleotídicas por sítio/ano, foi possível inferir que os Hantavírus teriam aproximadamente 1917 anos. O processo de dispersão dos Hantavírus pelo mundo teria ocorrido há aproximadamente 500 anos, e a introdução destes vírus nas Américas teria ocorrido há 549 anos (95% HPD 1555-341 anos), via América Central ou México, originando os Hantavírus adaptados aos roedores da subfamília Neotominae, e pelo Brasil surgindo há 406 anos (95% HPD 1150-250 anos) os Hantavírus associados a roedores da subfamília Sigmodontinae, e posteriormente dispersaram para todo o continente sul-americano. O trabalho contribui de forma relevante para o diagnóstico das infecções por Hantavírus com a one-step RT-PCR em tempo real SYBR Green I e também, contribui para o entendimento da filogenia e história destes vírus, oferecendo subsídios ao entendimento sobre como teria ocorrido o espalhamento dos Hantavírus pelo mundo. / The genus Hantavirus is included in the family Bunyaviridae are viruses emerging carried by rodents, which can infect humans causing serious illness. In the Americas, the Hantavirus causing a pulmonary syndrome (HPS) with high lethality. About 1,600 cases of HPS have been reported in Brazil, cause over 1600 deaths. Seven species of Hantavirus are known in Brazil, including Araraquara virus circulating in Cerrado regions (or Savannah regions) of the related in rodents Necromys lasiurus. The development of a real-time RT-PCR for detection and quantitation of Araraquara virus, here we show the steps for developing a one-step SYBR Green real-time RT-PCR for virus Araraquara which proved to be specific for the genus and capable of detecting up to 10 copies of viral RNA per ml in the sample. Furthemore, we performed a phylogenetic analysis using Bayesian algorithms, with 190 complete sequences of the nucleoprotein gene, originating from 30 countries over a 25 year period (1985-2010) that were available in GenBank (NCBI). Based on an average rate of 6.8 x 10-4 (2.5 x 10-4 - 1 x 10-3) nucleotide substitutions per site/year, it was possible to infer that the Hantavirus would be about 1917 years old. The Hantavirus spreading in the world have occurred for nearly 500 years, and the introduction of these viruses have occurred in the Americas 549 years ago (95 years% HPD 1555-341) bye Central America or Mexico, causing the Hantavirus adapted to rodents subfamily Neotominae, and Brazil emerged 406 years ago (95% HPD 1150-250 years) the Hantavirus associated with rodents subfamily Sigmodontinae, and subsequently disseminated to South America. The work contributes significantly to the diagnosis of Hantavirus infections with one-step SYBR Green real-time RT-PCR and also contributes to an understanding of the phylogeny and evolutionary history of these viruses, offering subsidies have occurred understanding of how the Hantavirus spread of the worldwide.
54

Pesquisa de anticorpos anti-Leptospira spp. e anti-Hantavirus em grupos ocupacionais do município de Garanhuns no estado de Pernambuco

SILVA, Gesika Maria da 24 February 2014 (has links)
Submitted by (edna.saturno@ufrpe.br) on 2016-07-25T11:00:10Z No. of bitstreams: 1 Gesika Maria da Silva.pdf: 1078979 bytes, checksum: 16c10f51f06bb62881de2a9fd68eba5a (MD5) / Made available in DSpace on 2016-07-25T11:00:11Z (GMT). No. of bitstreams: 1 Gesika Maria da Silva.pdf: 1078979 bytes, checksum: 16c10f51f06bb62881de2a9fd68eba5a (MD5) Previous issue date: 2014-02-24 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The objective of the present work was to determine the presence of anti-Hantavirus antibodies and anti-Leptospira spp. occupational groups in the municipality of Garanhuns Pernambuco State, Brazil. To perform the serology for Hantavirus and leptospirosis, 156 and 154 samples were obtained, respectively. The method used for the detection of IgG antibodies to Hantavirus N protein was Araraquara in-house ELISA serology and leptospirosis was used technique Microscopic Agglutination Test (MAT). To analyze the risk factors applied a questionnaire with objective questions. The prevalence of anti-Hantavirus Antibodies were 1.9 % (3/156 CI 0.4 %-5.5%) , with two reagent samples with titers of 200 (66.7%) and 400 (33.3%). All seropositive individuals to Hantavirus (100.0%) in this study were male and the village. Regarding age, there was a higher number of seropositive subjects aged between 18 and 40 years (p=0.009). The prevalence of antibodies to Leptospira spp. was 5.2 % (8/154 CI 2.2%-9.9%), a prevalence of 5.7 % (5/88 CI 1.8 %-12 7 % ) participants was observed in the urban area, and countryside of 4.6% (3/66 , CI 0.9%-12.7%). The most common serotypes were the Grippotyphosa (12.5 %) in rural areas and in the urban area autumnalis (12.5 %), while the Wolffi (25.0%) and Australis (50.0%) were observed both in rural areas as in urban. In the analysis of risk factors, no association was observed between these variables and serology. This was the first study conducted in the city of Garanhuns to report the presence of IgG anti-Hantavirus in human serum samples and report the presence of anti-Leptospira spp. in urban and rural workers of the municipality. These findings draw attention to the care and conduct research in areas where there is a low prevalence and even silent areas, because this way of control and prevention measures can be implemented in order to ensure the health of the exposed population. / Objetivou-se com o presente trabalho determinar a presença de anticorpos anti-Hantavirus e anti-Leptospira spp. em grupos ocupacionais do município de Garanhuns no Estado de Pernambuco, Brasil. Para a realização da sorologia para hantavirose e leptospirose, foram obtidas 156 e 154 amostras, respectivamente. O método utilizado para a detecção de anticorpos IgG contra a proteína N do Hantavirus Araraquara foi o ELISA in house e para a sorologia de leptospirose, utilizou-se a técnica de Soroaglutinação Microscópica (MAT). Para análise dos fatores de risco aplicou-se um questionário com perguntas objetivas. A prevalência de anticorpos anti-Hantavirus foi de 1,9% (3/156; I.C. 0,4% - 5,5%), com duas amostras reagentes com títulos de 200 (66,7%) e uma de 400 (33,3%). Todos os indivíduos sororreagentes para Hantavirus (100,0%) desta pesquisa eram do sexo masculino e da zona urbana. Em relação à idade, observou-se um maior número de sororreagentes na faixa etária entre 18 e 40 anos (p=0,009). A prevalência de anticorpos anti-Leptospira spp. foi de 5,2% (8/154; I.C. 2,2% - 9,9%), sendo observada nos participantes da zona urbana uma prevalência de 5,7% (5/88; I.C. 1,8% - 12,7%) e nos da zona rural 4,6% (3/66; I.C. 0,9% - 12,7%). Os sorovares mais frequentes foram o Grippotyphosa (12,5%) na área rural, e na área urbana o Autumnalis (12,5%), enquanto o Wolffi (25,0%) e o Australis (50,0%) foram verificados tanto na área rural como na urbana. Na análise de fatores de risco não foi observada associação entre as variáveis estudadas e a sorologia. Este foi o primeiro estudo realizado no município de Garanhuns a relatar a presença de IgG anti-Hantavirus em amostras séricas humanas e relatar a presença de anticorpos anti-Leptospira spp. em trabalhadores urbanos e rurais do município. Estes achados alertam para a atenção e realização de pesquisas em áreas em que há uma baixa prevalência e até mesmo para áreas silenciosas, pois desta forma medidas de controle e prevenção poderão ser implementadas com o intuito de garantir a saúde da população exposta.
55

Desenvolvimento de teste rápido para diagnóstico de Hantavirose humana / Development of rapid test for diagnosis of human Hantavirus

Guimarães, João Pedro Tôrres 12 April 2017 (has links)
Submitted by JÚLIO HEBER SILVA (julioheber@yahoo.com.br) on 2017-04-19T19:12:43Z No. of bitstreams: 2 Dissertação - João Pedro Tôrres Guimarães - 2017.pdf: 4247262 bytes, checksum: 8d423b0ec9df0ffdc2bb269e4572c28a (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-04-20T14:41:16Z (GMT) No. of bitstreams: 2 Dissertação - João Pedro Tôrres Guimarães - 2017.pdf: 4247262 bytes, checksum: 8d423b0ec9df0ffdc2bb269e4572c28a (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-04-20T14:41:16Z (GMT). No. of bitstreams: 2 Dissertação - João Pedro Tôrres Guimarães - 2017.pdf: 4247262 bytes, checksum: 8d423b0ec9df0ffdc2bb269e4572c28a (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-04-12 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Human Hantavirosis is a serious lung disease caused by Hantavírus, pathogen that is related mainly with wild rodents, insectivorous animals and small mammals (shrews, moles and bats). In humans, the disease is called Hantavírus Cardiopulmonary Syndrome (HCPS), which has high mortality rates (~ 50%). In Brazil, 1,871 cases of HCPS have been confirmed, with 789 deaths between the years 1993 to 2016. The symptoms in humans are not very characteristic in the initial stage, and very similar to diseases such as Dengue and Yellow Fever, making it difficult to diagnose, with a need of fast and accurate diagnostic methods for Hantaviruses. To assist in the diagnosis of Hantavírus, we aim to develop a quick and simple test based on immunochromatography. This paper presents results obtained with 3 prototypes of tests compoused by a nitrocellulose membrane (NC) impregnated in the form of a line with the recombinant nucleocapsid protein (rN) Hantavírus-specific, as the capture agent and another parallel line impregnated with protein A, as reaction control. In the NC edges we have a sample zone composed of cellulose fiber and a glass microfiber tape containing the anti-IgM antibodies and / or anti-human IgG conjugated to colloidal gold and at the other end an absorption zone composed of cellulose fiber. We evaluated 163 samples, among them, positive serum for Hantavírus, Dengue, Mayaro, Oropouche, Yellow fever, Malaria (P. falciparum) Malaria (P. vivax), Parvovirus B19, Rubella, HIV, Chikungunya and samples from health donors. After several evaluations, the prototype for the detection of IgM and IgG simultaneously, using the C concentration of protein rN, cutoff point 1 and reading time of the results of 10 minutes was chosen, presenting 100% sensitivity, 99, 3% specificity, 90.9% VPP and 100% VPN. It is expected that the product of this study helps in the diagnosis of severe cases of Hantavírus improving the prognosis of patients and reducing the high rates of HCPS fatality, moreover, helping to promote health by conducting epidemiological studies thereby promoting the construction of strategies to prevent Hantavírus infection. / A Hantavirose humana é uma doença pulmonar grave causada pelo Hantavírus, patógeno que está relacionado, principalmente, com roedores selvagens, animais insetívoros e pequenos mamíferos (musaranhos, toupeiras e morcegos). Em humanos, a doença é denominada Síndrome Cardiopulmonar pelo Hantavírus (HCPS), a qual possui altos índices de mortalidade (~50%). No Brasil, foram confirmados 1.871 casos de HCPS, com 789 óbitos entre os anos de 1993 a 2016. Os sintomas em humanos são pouco característicos na fase inicial, semelhantes aos de doenças como a Dengue e Febre Amarela, o que dificulta o diagnóstico. Portanto, existe a necessidade de métodos de diagnóstico rápidos e precisos para Hantavirose. Para auxiliar no diagnóstico da Hantavirose, objetivamos desenvolver um teste rápido e simples, baseado em imunocromatografia. Neste trabalho são apresentados resultados obtidos com 3 protótipos de testes compostos por uma membrana de nitrocelulose (NC) com a proteína do nucleocapsídeo recombinante (rN) específica de Hantavírus impregnada na forma de uma linha, atuando como agente de captura dos anticorpos na amostra, e outra linha paralela posterior à do antígeno com proteína A como controle da reação. Numa das extremidades da NC temos a zona receptora de amostra composta por fibra de celulose e uma fita de microfibra de vidro contendo os anticorpos anti-IgM e/ou anti-IgG humanas conjugados com ouro coloidal e, na outra extremidade por uma zona de absorção composta por fibra de celulose. Foram avaliadas 163 amostras, dentre elas, soros positivos para Hantavírus, Dengue, Mayaro, Oropouche, Febre Amarela, Malária (P. falciparum), Malária (P. vivax), Parvovírus B19, Rubéola, HIV, Chikungunya e soros de doadores de sangue sadios. Após diversas avaliações, o protótipo para detecção de IgM e IgG simultaneamente, com concentração C de proteína rN na linha teste, ponto de corte 1 e tempo de leitura dos resultados de 10 minutos foi escolhido, apresentando 100% de sensibilidade, 99,3% de especificidade, 90,9% de VPP e 100% de VPN. Espera-se que o produto deste estudo auxilie no diagnóstico dos casos graves de Hantavirose melhorando o prognóstico dos pacientes e diminuindo os altos índices de fatalidade de HCPS, além disso, auxiliando na promoção à saúde, através da realização de estudos epidemiológicos promovendo assim a construção de estratégias de prevenção da infecção pelo Hantavírus.
56

Avaliação do sistema de vigilância da hantavirose no estado de Goiás – 2007 a 2012 / Evaluation of the hantavirosis surveillance system in the state of Goiás - 2007 to 2012

Machado, Daniella Carpaneda 27 February 2015 (has links)
Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2017-05-26T14:04:02Z No. of bitstreams: 2 Dissertação - Daniella Carpaneda Machado - 2015.pdf: 2199589 bytes, checksum: 80dfa32195908d14c34b1e91c06e3de7 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-05-26T14:04:23Z (GMT) No. of bitstreams: 2 Dissertação - Daniella Carpaneda Machado - 2015.pdf: 2199589 bytes, checksum: 80dfa32195908d14c34b1e91c06e3de7 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-05-26T14:04:23Z (GMT). No. of bitstreams: 2 Dissertação - Daniella Carpaneda Machado - 2015.pdf: 2199589 bytes, checksum: 80dfa32195908d14c34b1e91c06e3de7 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2015-02-27 / The hantavirus is an emerging zoonosis, considered a public health problem due to its high mortality and hospitalization. Transmission occurs by exposure to excreta of infected wild rodents, primarily via aerosol. The aim of this study is to evaluate the hantavirus monitoring system in the State of Goiás, in the period 2007 to 2012. This is an observational, descriptive and cross-sectional study in which the clinical and epidemiological features of hantavirus were analyzed and their attributes according to models proposed by the Updated Guidelines for Evaluating Public Health Surveillance Systems and Framework for Evaluating Public Health Surveillance Systems for Early Detection of outbreaks of the Center for Disease Control and Prevention and the Department of Health Surveillance. 63 cases were confirmed in the analyzed period. The disease has the highest number of confirmed cases in absolute numbers in 2009, with higher positivity of the relationship notification / confirmation in 2008. The municipalities of greater nudges Annapolis, Goiânia and Jataí. The hantavirus predominantly hit men, race / brown color, living in an urban area with high school education, being related to agricultural occupations and largest exhibitions in environments cleaning situations and in direct contact or with traces of a mouse . Most cases were reported in the first four days of the onset of symptoms, with signs of fever, dyspnea, and myalgia. He has performed many laboratory tests and imaging. However, it was demonstrated deficit of completeness in these fields in the reporting forms. The most notable changes are nonspecific hematocrit> 45% and thrombocytopenia, and on imaging, diffuse pulmonary infiltrates. More than 85% of the cases were confirmed by laboratory testing (IgM) and clinical form of hantavirus cardiopulmonary syndrome. High hospitalization rate, especially on the first day of care, was quite considerable and demand for organ support. The municipalities with the highest indication of Infection Likely Place are Annapolis and Jataí, in rural areas and work environment, with closure in time in just over 60% of cases. Although theoretically the system is useful in practice, low valuation is observed quantitative attributes (sensitivity, predictive value of positive, opportunity, stability) and qualitative (simplicity, flexibility and acceptability - in the question data quality assessment is average the bad). As for the management indicators was observed weaknesses in their use. From the analysis of the hantavirus surveillance system in Goias, 2007-20012, it was concluded that the current system is fragile. It is suggested a number of recommendations in order to give more useful reducing the socioeconomic impact of the disease through the continuous improvement of services provided by various levels and professional sectors, as well as the construction of an education service in health and prevention mainly for environmental management measures that prevent / reduce the risk of the presence of possible rodents infected with the human environment. / A hantavirose é uma zoonose emergente, considerada um problema de saúde pública devido seu alto grau de letalidade e hospitalização. A transmissão ocorre pela exposição aos excretas de roedores silvestres infectados, principalmente via aerossol. O objetivo do presente estudo é avaliar o sistema de vigilância da hantavirose no Estado de Goiás, no período de 2007 a 2012. Trata-se de um estudo observacional, descritivo e transversal, no qual foram analisadas as características clínicas e epidemiológicas da hantavirose e seus atributos segundo modelos propostos pelo Updated Guidelines for Evaluating Public Health Surveillance Systems e Framework for Evaluating Public Health Surveillance Systems for Early Detection of Outbreaks do Center for Disease Control and Prevention e Secretaria de Vigilância em Saúde. Foram confirmados 63 casos no período analisado. A doença tem o maior número de casos confirmados em números absolutos em 2009, com maior positividade da relação notificação/confirmação em 2008. Os municípios de maior notificação foram Anápolis, Goiânia e Jataí. A hantavirose atingiu predominantemente homens, da raça/cor parda, residentes em zona urbana, com ensino médio completo, mostrando-se relacionada às ocupações agrícolas e com maiores exposições em situações de limpeza de ambientes e em contato direto ou com vestígios da presença de ratos. A maior parte dos casos foi notificada nos primeiros quatro dias do surgimento dos sintomas, com sinais de febre, dispneia e mialgia. Apresentou-se grande número de exames laboratoriais e de imagem. Entretanto, demonstrou-se déficit de completitude nestes campos nas fichas de notificação. As alterações inespecíficas mais marcantes são hematócrito >45% e trombocitopenia, e no exame de imagem, infiltrado pulmonar difuso. Mais de 85% dos casos foram confirmados por critério laboratorial (IgM) e na forma clínica de Síndrome Cardiopulmonar por Hantavírus. Elevada taxa de internação, principalmente no primeiro dia do atendimento, foi bastante considerável e com demanda de terapias de suporte. Os municípios com maior indicação de Local Provável de Infecção são Anápolis e Jataí, em zona rural e ambiente ocupacional, com encerramento em tempo oportuno em pouco mais de 60% dos casos. Apesar de teoricamente o sistema ser útil, na prática, observa-se baixa avaliação dos atributos quantitativos (sensibilidade, valor preditivo de positividade, oportunidade, estabilidade) e qualitativos (simplicidade, flexibilidade e aceitabilidade – no quesito qualidade dos dados a avaliação é de média a ruim). Quanto aos indicadores de gerenciamento, observou-se fragilidades em sua utilização. A partir da análise do sistema de vigilância da hantavirose em Goiás, 2007-20012, concluiu-se que o atual sistema é frágil. Sugere-se uma série de recomendações com o objetivo de lhe dar maior utilidade reduzindo o impacto socioeconômico da doença por meio da melhoria contínua dos serviços prestados pelos diversos níveis e setores de profissionais, bem como pela construção de um serviço de educação em saúde e prevenção, principalmente por medidas de manejo ambiental, que evitam/reduzem o risco da presença de possíveis roedores infectados no meio antrópico.
57

Abundância de roedores reservatórios de hantavírus no bioma da Mata Atlântica: efeitos da estrutura da paisagem e da escala de análise / Abundance of hantavirus reservoir rodents in the Atlantic Forest biome: effects of landscape structure and scale analysis

Amanda Francisco Prado 19 June 2015 (has links)
O risco transmissão de hantavírus para humanos na Mata Atlântica está diretamente relacionado à abundância de duas espécies de roedores, Oligoryzomys nigripes e Necromys lasiurus, reconhecidas como os principais reservatórios destes vírus naquele bioma. Ambas as espécies são beneficiadas por alterações antrópicas, porém, pouco se sabe sobre quais parâmetros da estrutura da paisagem e a escala espacial (em termos de extensão e resolução) em que a paisagem influencia a abundância destas espécies. Este trabalho procura preencher essa lacuna de conhecimento e investigar como uma definição adequada de parâmetros e escalas pode afetar modelos de extrapolação espacial das abundâncias destas espécies, o que pode ter amplas implicações para um melhor controle da propagação de hantavírus. O trabalho foi desenvolvido em seis paisagens da Mata Atlântica no Planalto Paulista, próximas ao local do primeiro registro de hantavirose no Brasil, sendo três de mata contínua e três paisagens fragmentadas, as quais diferiam com relação à porcentagem de cobertura florestal (11, 31 e 49%). Os pequenos mamíferos foram coletados em contextos de fragmentos florestais, mata contínua e matriz, totalizando 104 pontos de coleta. A análise, baseada em uma abordagem de seleção de modelos, considerou a estrutura da paisagem em diferentes extensões espaciais ao redor dos pontos de coleta (raios de 200, 500 e 800 m), em três mapeamentos que diferiam quanto a suas resoluções espaciais (10, 30 e 260 m). A partir do melhor modelo selecionado para cada espécie e para cada resolução, foi feita uma extrapolação das abundâncias, através da qual comparou-se os resultados obtidos em cada mapeamento. Foram capturados 1074 indivíduos de O. nigripes, a maioria nos fragmentos florestais. A maior abundância observada ocorreu nos fragmentos da paisagem de 11% de mata, diminuindo gradativamente nas paisagens com maiores porcentagens de cobertura florestal. N. lasiurus foi quase que exclusivamente coletado na matriz e, a maioria, na paisagem de 11% de mata. A abundância de O. nigripes foi diferentemente influenciada pela cobertura florestal da paisagem dependendo do contexto (fragmentos, mata contínua e matriz) em que a espécie se encontrava e também foi influenciada pela cobertura florestal e densidade de borda em escala local (200 m). A abundância de N. lasiurus foi negativamente influenciada pela cobertura florestal em escalas mais locais e variou de acordo com o tipo de cultura agrícola. A escala que mais influenciou ambas as espécies foi a de 200 m. Os mapeamentos com resolução de 10 e 30 m foram mais semelhantes entre si do que quando comparados com o mapeamento de 260 m, o que se refletiu nos melhores modelos de abundância selecionados, assim como nas extrapolações das abundâncias. Nossos resultados mostram que estas duas espécies respondem à degradação das paisagens e que paisagens mais biodiversas impedem um grande aumento da abundância de espécies que atuam como reservatórios dos hantavírus. Os resultados reforçam a necessidade de serem tomadas medidas que impeçam ou diminuam o desmatamento e a degradação da Mata Atlântica, ou que incentivem a regeneração e restauração florestal, para que possam ser evitados outros surtos de hantavirose. Além disso, evidenciam a importância de se escolher adequadamente a resolução do mapeamento em estudos ecológicos, baseando-se em atributos biológicos da espécie estudada, e ressaltam que extrapolações de abundância das espécies reservatório feitas em escalas muito grosseiras (e.g. acima da escala de resposta das espécies) podem levar a erros expressivos, potencialmente reduzindo a efetividade de ações voltadas para o controle da propagação de hantavírus. / Hantavirus transmission risk to humans in the Atlantic Forest is directly related to the abundance of two rodents species, Oligoryzomys nigripes and Necromys lasiurus, recognized as the main reservoir species of Hantavirus in this biome. Both species benefit by landscape anthropogenic changes, however, the structural parameters and the spatial scale (in terms of extension and resolution) in which the landscape influences the abundance of these two species remains to be examined. This study aims to fill this research gap and specifically test how a proper definition of parameters and scales may affect spatial extrapolation models of the abundance of these species, what may have broad implications for a better control of Hantavirus. This study was conducted in Plateau Paulista, Atlantic Forest, near to the first Hantavirus case in Brazil. Six landscapes were selected, being three control areas (continuous forest) and three fragmented landscapes, which differ in relation to the forest cover percentage (11, 31 e 49%). Small mammals were colected in forest patches, continuous forest and matrix contexts, totaling 104 collect stations. We performed a model selecting approach considering the landscape structure in different spatial extensions around each colect station (200, 500 and 800 m radius) in three different mapping that differ in their spatial resolution (10, 30 and 260 m). The best selected model to each specie in each map resolution was used to extrapolate the species abundance for the entire fragmented landscapes studied, whereby the obtained results for each mapping resolution were compared. A total of 1074 individuals of O. nigripes were captured, most of them in forest patches. The highest abundance ocurred in forest patches of the 11% forest cover landscape, decreasing gradually in landscapes with higher forest cover percentage. N. lasiurus was almost exclusively colected in the matrix with most of the individuals being colected in the 11% forest cover landscape. The abundance of O. nigripes was differently influenced by the landscape forest cover depending on the context (forest patches, continous forest and matrix) in which the species was colected and it was influenced by forest cover and edge density at the local scale (200 m). The abundance of N. lasiurus was negatively influenced by forest cover at more local scales and varied according with type of crop. The scale that most influenced both species was 200 m. The 10 and 30 m resolution mappings were more similar to each other than with the 260 m resolution mapping, what reflected on the best selected models of abundance, as well as on the abundance extrapolations. Our results show that these two species respond to the landscape degradation and that more biodiverse landscapes prevent the increase of the species abundance that act as Hantavirus reservoirs. Ours results reinforce the need of measures that prevent or reduce the Atlantic Forest deforestation and degradation, or encourage the regeneration and forest restoration, in order to avoid other Hantavirus outbreaks. Besides, our results evidence the importance of chosing accordingly the mapping resolution in ecological studies, which should consider the biological traits of the studied species. Additionally we highlight that abundance extrapolations of reservoir species done in a very coarse grain resolution (e.g. above the species response scale) may lead to significant errors, potentially reducing the effectiveness of actions aimed at controlling Hantavirus spread.
58

Human antibody responses to hantavirus recombinant proteins & development of diagnostic methods

Elgh, Fredrik January 1996 (has links)
Rodent-borne hantaviruses (family Bunyaviridae) cause two distinct human infections; hemorrhagic fever with renal syndrome (HFRS) and hantavirus pulmonary syndrome (HPS). HFRS is a common viral zoonosis, characterized by fever, renal dysfunction and hemostatic imbalance. Four HFRS-associated hantaviruses have been described: Hantaan virus and Seoul virus mainly found in Asia, Dobrava virus, encountered in the Balkan region and Puumala virus (PUU), causing mild HFRS (nephropathia epidemica; NE) in Europe. HPS, recently discovered in the Americas, involves adult respiratory distress syndrome with a high mortality rate and is caused by Sin Nombre virus. Hantaviruses are enveloped and carry a RNA genome which encodes a polymerase, two glycoproteins and a nucleocapsid protein. The latter elicits a strong humoral immune response in infected patients. The clinical diagnosis of hantavirus infections has until recently relied on serological confirmation by immunofluorescense assay (IFA) and enzyme-linked immunosorbent assay (ELISA) using cell culture derived viral antigens. Due to the hazardous nature of hantaviruses and variable virus yield in cell culture we aimed at using recombinant hantavirus proteins for serological purposes. We expressed PUU N in E. coli (PUU rN) and found that high levels of IgM to this protein could be detected at onset of NE. This indicated that it was useful as the sole antigen for serodiagnosis. Our finding was confirmed by comparing IFA and PUU rN ELISA using 618 sera collected at the regional diagnostic laboratory. Full-length PUU rN is difficult to purify due to aggregation to E. coli remnants. We therefore located the important domain for the humoral immune response by utilizing truncated PUU rN proteins to its amino-terminal region (amino acid 7-94). Amino acid 1-117 of N of the five major human hantavirus pathogens were produced in E. coli. Serological assays based on them could detect IgM and IgG serum responses in 380 HFRS and HPS patients from Sweden, Finland, Slovenia, China, Korea and the USA with high sensitivity. In an epidemiological investigation of hantavirus serum responses in European Russia we unexpectedly found antibody responses to the hantaviruses found in east Asia and the Balkan region in 1.5 %, speaking in favour for the presence of such virus in this region. The degree of cross reactivity within the hantavirus genus was adressed by following the serum responses in NE patients. We found an increase of cross reactivity during the maturation of the immune response from onset of disease up to three years by comparing the IgG reactivity towards the hantavirus aminoterminal rN proteins. The first human isolate of the causative agent of NE in Scandinavia was recovered in cell culture from phytohemagglutinin stimulated leukocytes. Serological analysis revealed that this virus belongs to the PUU hantavirus serotype, distinct from the rodent prototype PUU Sotkamo. The human PUU Umeå is unique but genetically similar to rodent isolates from northern Sweden. / digitalisering@umu.se
59

Pathogenesis of hantavirus infection in the endothelial cell model

Kraus, Annette Alexandra 20 October 2004 (has links)
Hantaviren sind wichtige menschliche Krankheitserreger und können das Hämorrhagische Fieber mit renalem Syndrome (HFRS) auslösen, welches sich durch endotheliale Dysfunktion kennzeichnet. Pathogene und nicht-pathogene Hantaviren replizieren sich in Endothelzellen, ohne zytopathische Effekte auszulösen. Dies legt nahe, dass immunpathologische Mechanismen eine entscheidende Rolle in der Pathogenese spielen. Wir haben die antivirale Antwort nach Infektion mit dem pathogenen Hantaan Virus (HTNV) sowie mit dem weniger pathogenen Tula Virus (TULV) in humanen Endothelzellen (HUVEC) verglichen. Die mit HTNV und auch die mit TULV infizierten Zellen zeigten eine erhöhte Expression von Antigen-präsentierenden Molekülen. Hierbei induzierte TULV die Expression von HLA Klasse I-Molekülen noch effizienter. HTNV sorgte für die Induktion von Interferon (IFN)-???während dieses Zytokin im Überstand von TULV-infizierten HUVEC kaum nachzuweisen war. Trotzdem konnte die Hochregulation von HLA Klasse I-Molekülen auf HTNV- und TULV-infizierten Zellen durch anti-IFN-?-Antikörper blockiert werden. Interessanterweise wurde das antiviral wirksame MxA-Protein, welches die virale Replikation hemmt, bereits 16 Stunden nach einer Infektion mit TULV induziert. Im Gegensatz dazu war MxA in HTNV-infizierten Zellen erst nach 48 Stunden der Infektion nachzuweisen. Der Kinetik der MxA-Expression entsprechend, replizierte sich TULV nur sehr schwach in HUVEC, wohingegen HTNV-infizierte Zellen hohe Virustiter aufwiesen, die nach 48 Stunden der Infektion wieder zurückgingen. Beide Hantavirus-Spezies waren jedoch gleichermaßen effizient in der Lage, sich in Vero E6-Zellen zu replizieren, denen die IFN-induzierte MxA-Antwort fehlt. Die verzögerte Induktion des MxA nach einer Infektion der HUVEC mit HTNV, könnte die Virusausbreitung ermöglichen und mit zur Pathogenese des HFRS beitragen. Das Risiko, sich während der Arbeit im Forschungslabor versehentlich mit Hantaviren zu infizieren, macht spezielle Sicherheitsmaßnahmen zwingend erforderlich. Die Wirkung von chemischen oder physikalischen Inaktivierungsmethoden wurde an HTNV-infizierten Proben untersucht. Die beschriebenen Maßnahmen zur Virus-Desinfektion sind geeignet, eine sichere Handhabung der Proben zu gewährleisten. / Hantaviruses represent important human pathogens and can induce hemorrhagic fever with renal syndrome (HFRS), which is characterised by endothelial dysfunction. Both pathogenic and nonpathogenic hantaviruses replicate without causing any apparent cytopathic effect suggesting that immunopathological mechanisms play an important role in pathogenesis. We compared the antiviral response triggered by Hantaan virus (HTNV), a pathogenic hantavirus associated with HFRS, and Tula virus (TULV), a rather nonpathogenic hantavirus, in human umbilical vein endothelial cells (HUVEC). Both HTNV- and TULV-infected cells showed increased levels of molecules involved in antigen presentation. However, TULV-infected HUVEC more rapidly upregulated HLA class I molecules. Interestingly, HTNV clearly induced the production of interferon (IFN)-( whereas expression of this cytokine was barely detectable in the supernatant or in extracts from TULV-infected HUVEC. Nevertheless, upregulation of HLA class I on both TULV- and HTNV-infected cells could be blocked by neutralising anti-IFN-( antibodies. Most strikingly, antiviral MxA protein, which interferes with hantavirus replication, was induced already 16 h after infection with TULV. In contrast, HTNV-infected HUVEC showed no expression of MxA until 48 h postinfection. In accordance with the kinetics of MxA expression TULV only inefficiently replicated in HUVEC whereas HTNV-infected cells produced high titers of virus particles that decreased 48 h postinfection. Both hantavirus species, however, could replicate equally well in Vero E6 cells which lack an IFN-induced MxA response. Thus, a delayed induction of antiviral MxA in endothelial cells after infection with HTNV could allow viral dissemination and contribute to the pathogenesis leading to HFRS. The potential risk of accidental infection by hantaviruses in a clinical or research laboratory necessitates special precautionary measures. To study the elimination of hantavirus infectivity, the effects of different chemical and physical inactivation and depletion procedures were investigated on HTNV-containing materials. The virus inactivation and depletion methods described herein are suitable to prepare non-infectious samples for further use in immunological, virological and cell biological assays.
60

Dobrava and Tula hantaviruses from Central Europe

Klempa, Boris 09 February 2005 (has links)
Hantaviren (Familie Bunyaviridae) sind Erreger, die von Nagetieren auf den Menschen übertragen werden und Hämorrhagische Fieber mit Renalem Syndrom (HFRS) auslösen. Die vorgelegte Arbeit beinhaltet derartige Ergebnisse zu zwei europäischen Hantaviren, dem Dobravavirus (DOBV) und dem Tulavirus (TULV). DOBV ist ein wichtiger HFRS-Erreger in Europa. DOBV Stämme kommen in mindestens zwei Nagerspecies, der Gelbhalsmaus (Apodemus flavicollis) und der Brandmaus (A. agrarius) vor. In Übereinstimmung mit diesen natürlichen Wirten bilden die Virusstämme zwei genetische Linien: DOBV-Af und DOBV-Aa. Die phylogenetischen Analysen von den Nukleotidsequenzen der S-, M- und L-Segmente von sympatrisch vorkommenden DOBV-Af und DOBV-Aa Stämmen aus Mitteleuropa zeigten das Vorkommen von Reassortmentprozessen der Genomsegmente während der Evolution der Virusspecies. Ausserdem, wurde die virale Nukleotidsequenz aus einem DOBV-seropositiven HFRS-Patienten aus Detschland amplifiziert. Damit wurde erstmalig der molekulare Beweis erbracht, dass DOBV in Mitteleuropa HFRS auslöst und dass die DOBV-Aa Linie humanpathogen ist. Aus einer in der Slowakei gefangenen A. agrarius Maus haben wir ein neues Virusisolat gewonnen, welches "Slovakia (SK/Aa)" genannt wurde. SK/Aa ist das bisher einzige Virusisolat, das die DOBV-Aa Linie repräsentiert. Es wurde gemeinsam mit einem Isolat der DOBV-Af Linie zur vergleichenden Typisierung der Antikörper von mitteleuropäischen HFRS-Patienten mittels Fokusreduktionsneutralisationstest eingesetzt. Die Seren der meisten Patienten zeigten die höchsten neutralisierenden Antikörpertiter gegenüber SK/Aa, was die Schlussfolgerung zulässt, dass DOBV-Aa Stämme für die meisten DOBV-Infektionen in Mitteleuropa verantwortlich sind. TULV wird durch die Feldmaus (Microtus arvalis) beherbergt. Die Fähigkeit zur Auslösung von HFRS war bisher wenig bekannt. Wir haben den ersten Fall von HFRS gefunden, der mit einer TULV Infektion assoziiert ist. Aus demselben geographischen Gebiet in Nordostdeutschland konnten aus Feldmäusen TULV Nukleotidsequenzen amplifiziert werden. In phylogenetischen Analysen clustern sie mit Stämmen aus Polen und bilden mit diesen gemeinsam eine eigene, neue genetische Linie. Ausser dem hier untersuchten DOBV und dem länger bekannten Puumalavirus ist TULV offenbar das dritte Hantavirus, das in Mitteleuropa HFRS hervorruft. / Hantaviruses (Bunyaviridae family) are rodent-borne bunyaviruses that cause hemorrhagic fever with renal syndrome (HFRS) in Eurasia. This thesis presents novel data about two European hantaviruses, Dobrava virus (DOBV) and Tula virus (TULV). DOBV is an important etiologic agent of HFRS in Europe. DOBV strains were found to be hosted by at least two different rodent species, yellow-necked mouse (Apodemus flavicollis) and striped field mouse (A. agrarius). According to their natural hosts they form the distinct genetic lineages DOBV-Af and DOBV-Aa, respectively. We have determined and analysed the complete S and M, and partial L segment nucleotide sequences of sympatrically occurring DOBV-Af and DOBV-Aa strains from Central Europe. Molecular phylogenetic analyses gave evidence for genetic reassortment in the evolution of the virus species. Moreover, we amplified a DOBV-Aa nucleotide sequence from a DOBV-seropositive HFRS patient from Germany. This is the first molecular identification of human infection by DOBV in Central Europe and the first direct proof that a virus strain related to the DOBV-Aa lineage, carried by A. agrarius rodents, is able to cause HFRS. Under biosafety level 3 conditions, we have established a DOBV isolate named Slovakia (SK/Aa) from an A. agrarius animal captured in Slovakia. SK/Aa, as the only isolate clearly belonging to the DOBV-Aa lineage, can be taken as the representative of this virus lineage. The new virus isolate, in comparison to a DOBV-Af strain, was used for serotyping neutralising antibodies of HFRS patients in Central Europe by the use of a focus reduction neutralisation assay. Most patients'' sera exhibited a higher end-point titer towards SK/Aa suggesting that DOBV-Aa strains are responsible for most of the DOBV HFRS cases in this region. TULV is carried by European common voles (Microtus sp.). Its pathogenic potential for humans was rather unknown. We have described the first case of HFRS which can be associated with TULV infection. Moreover, TULV strains detected in M. arvalis near the home village of the patient in North-East Germany clustered with strains from Poland and represent a new, well-supported genetic lineage within the TULV species. In addition to DOBV and longer known Puumala virus, TULV is most likely an additional causative agent of HFRS in Central Europe.

Page generated in 0.0848 seconds