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No. of bitstreams: 1 luisadeoliveira.pdf: 1689764 bytes, checksum: 7af6e626808d1ab5d4fc1de9be514aaa (MD5) Previous issue date: 2014-10-10 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Hemosporídeos de aves silvestres são considerados importantes agentes etiológicos e podem causar danos às populações dos hospedeiros. O presente estudo teve como objetivos: determinar a prevalência e a parasitemia para Plasmodium spp. e Haemoproteus spp. de Passeriformes da Mata Atlântica de Minas Gerais, por meio de dois métodos de diagnóstico, microscopia e nested PCR e caracterizar morfologicamente a espécie Plasmodium (Haemamoeba) lutzi Lucena, 1939. Amostras de sangue foram obtidas por punção da veia braquial para preparação de esfregaços que foram fixados em metanol e corados em Giemsa. Foram amostradas 237 aves pertencentes a 18 famílias e 56 espécies da ordem Passeriformes provenientes do IBAMA e capturadas no Jardim Botânico da Universidade Federal de Juiz de Fora (JB-UFJF). A prevalência para Plasmodium spp. foi 63,63% em aves do IBAMA e 26,25% em aves do JB-UFJF, apenas três indivíduos encontraram-se parasitados por Haemoproteus spp., sendo dois (2,5%) provenientes do IBAMA e um (0,62%) do JB-UFJF. A parasitemia média encontrada para Plasmodium spp./Haemoproteus spp. foi de 0,08 (± 0,08) no IBAMA e 0,05 (± 0,04) no JB-UFJF. O maior grau de parasitemia média foi registrado nas espécies Turdus albicollis, Zonotrichia capensis (0,22%), Turdus rufiventris (0,18% ± 0,29), Gnorimopsar chopi (0,1% ± 0,07) no IBAMA e Turdus rufiventris (0,17 % ± 0,13), Arremon semitorquatus (0,11% ± 0,13) no JB-UFJF. Foi identificada em uma das aves (A. semitorquatus), a presença da espécie Plasmodium (H.) lutzi, a qual foi morfologicamente caracterizada. A prevalência registrada é considerada alta, entretanto verificou-se uma baixa parasitemia, o que pode estar relacionado à evolução crônica da infecção. Infecções agudas por Plasmodium spp. levam ao aparecimento de sinais clínicos com expressão rápida dos sintomas, sendo que nos casos mais graves pode ocorrer a morte do hospedeiro. Visto a elevada prevalência, levantamentos acerca de infecções por hemoparasitos em aves silvestres podem ajudar na elaboração de estratégias de profilaxia e tratamento de doenças parasitárias para a conservação das espécies. / Hemosporidian wild birds are considered important etiological agents and can cause damage to populations of hosts. The present study aimed to: ¹determine prevalence and parasitemia for Plasmodium spp. and Haemoproteus spp. Passeriformes of the Atlantic Forest of Minas Gerais, through two diagnostic methods, microscopy and nested PCR; and caracterize morphologically the species Plasmodium (Haemamoeba) lutzi Lucena, 1939. Blood samples were obtained by puncturing the brachial vein for preparation of smears, fixed in methanol and stained with Giemsa. 237 birds belonging to 18 families and 56 species of the order Passeriformes from IBAMA were sampled and captured in the Botanical Garden of the Universidade Federal de Juiz de Fora (BG-UFJF). The prevalence of Plasmodium spp. in birds of IBAMA was 63.63% and 26.25% in birds of BG-FUJF, only three individuals were infected by Haemoproteus spp., two (2.5%) from IBAMA and one (0.62 %) of BG-FUJF. The average parasitemia found for Plasmodium spp./ Haemoproteus spp. was 0.08 (± 0.08) at IBAMA and 0.05 (± 0.04) in BG-UFJF. The highest degree of mean parasitaemia was recorded in the species Turdus albicollis, Zonotrichia capensis (0.22%), Turdus rufiventris (0.18% ± 0.29), Gnorimopsar chopi (0.1% ± 0.07) at IBAMA and Turdus rufiventris (0.17% ± 0.13), Arremon semitorquatus (0.11% ± 0.13) in BG-UFJF. Was identified in one of the birds (A. semitorquatus) by means of morphology, the presence of Plasmodium (H.) lutzi species, which was characterized morphologically. Registered prevalence is considered high, however a low parasitaemia was found, which may be related to chronic course of infection.. Acute infections with Plasmodium spp. lead to the onset of clinical signs with rapid symptom expression, and in severe cases death canoccurat the host. Since the high prevalence surveys about hemoparasites infections in wild birds can help in developing strategies for prophylaxis and treatment of parasitic diseases to species conservation.

O Vírus do Nilo Ocidental, do inglês West Nile virus (WNV) é um patógeno emergente que é amplamente distribuído na América do Norte e Central. A recente introdução na América do Sul chamou a atenção para a propagação do WNV em países Latino Americanos. O ciclo de transmissão envolve mosquitos, pássaros, cavalos e seres humanos. A avaliação sorológica realizada nestes estudo foi composta por 678 soros de equídeos e 478 soros de aves, realizada por meio do ensaio ELISA de bloqueio específico para WNV e somente as amostras com resultados positivos foram confirmadas por testes de neutralização por redução em placas (PRNTs). A análise molecular foi realizada em soros de 1.241 equídeos saudáveis e em 63 macerados de cérebros de equídeos que morreram de encefalite e obtiveram resultados previamente negativos para outros patógenos. Também testamos swabs de 3.445 aves pelo método molecular, além de amostras de 24 morcegos e 11 onças. As amostras analisadas foram coletadas em diferentes biomas do Brasil. Identificamos pelo ELISA anticorpos para o WNV em treze equídeos e cinco pássaros e o teste de PRNT90 confirmou positividade para o WNV em quatro amostras de equídeos coletadas em 2009 em uma região entre a Amazônia e o Pantanal. Nenhuma das amostras de aves positivas pelo ELISA foram confirmadas por PRNT90. Das 4.784 amostras testadas por RT-PCR, penas duas apresentaram resultados positivos para a detecção, sendo uma ave residente na região do Pantanal e um anatídeo na região do Maranhão, respectivamente. A circulação do WNV é confirmada pela presente pesquisa em larga escala, mesmo na ausência da detecção de casos clínicos. / West Nile virus (WNV) is an emergent pathogen that is widely distributed in North and Central America. The recent introduction in South America has focused attention on the spread of WNV across Southern American countries. The transmission network involves mosquitoes, birds, horses and humans. The serological evaluation of sera from 678 equids and 478 birds was performed using a WNV-specific blocking ELISA, and only the positive results were confirmed by plaque reduction neutralisation tests (PRNTs). Molecular analysis was performed on sera from 1241 healthy equids and on 63 macerates of brains from equids that died of encephalitis and had previously tested negative for other pathogens. We also tested swabs from 3.445 birds, 24 bats and 11 phanteras. The samples analysed were collected in different biomes of Brazil. We identified WNV antibodies by ELISA in thirteen equids and five birds, and PRNT90 confirmed WNV positivity in four equid samples collected in 2009 in an area between the Amazon and the Pantanal. None of the ELISA positive bird samples were confirmed by PRNT90. Of the 4.784 samples tested by RT-PCR, only two were positive for the detection, a resident bird in the Pantanal region and a duck in the region of Maranhão, respectively. WNV circulation is confirmed by this large scale survey even in the absence of detection of clinical cases.

Le virus du Nil occidental (VNO) est un arbovirus principalement transmis par les moustiques. Le cycle de transmission enzootique implique généralement une variété d’espèces d’oiseaux sur lesquelles se nourrissent de façon préférentielle divers moustiques, les principaux vecteurs enzootiques au Québec étant les moustiques du genre Culex (c’est-à-dire Culex pipiens et Cx. restuans). Des cas d’infection humaine par le VNO surviennent sporadiquement chaque année au Québec et on sait peu de choses sur les facteurs qui déterminent l’ampleur des éclosions chez les humains. Malgré l’existence de nombreuses études sur le virus du Nil occidental (VNO) aux États-Unis, y compris sur le rôle de réservoir des espèces d’oiseaux, et sur les changements alimentaires du moustique Culex (des oiseaux vers les mammifères), peu d'études équivalentes existent dans les régions voisines du Canada où le VNO est endémique. Ce travail vise à déterminer l’importance relative des différentes espèces d’oiseaux dans la transmission du VNO dans le sud du Québec. Nous nous sommes concentrés sur les espèces aviaires du corridor de migration de l’Atlantique Est (selon la base de données Avibase). Les espèces d’oiseaux ont ensuite été triées et sélectionnées en fonction de ce qui suit : 1) les taux de mortalité aviaire dus au VNO signalés dans les données de surveillance locale du Réseau canadien pour la santé de la faune, 2) la séroprévalence et la compétence des réservoirs du VNO en Amérique du Nord (d’après la littérature), 3) les estimations locales de la densité des oiseaux (d’après les données ebird) et 4) les données d’une étude sur les repas sanguins de Culex pipiens / Cx. restuans saisies entre 2008 et 2013 chez des moustiques de la région de Montréal. L’analyse a généré une liste de 67 espèces d’oiseaux potentiellement impliquées dans la circulation du VNO dans notre zone d’étude et nous avons émis des hypothèses quant à la contribution relative à l’amplification du VNO. Cette étude permettra de mieux comprendre les facteurs susceptibles d’influencer la circulation du VNO dans le sud du Québec et sera utile aux futures études de modélisation de la transmission enzootique du VNO. / West Nile virus (WNV) is an arbovirus that is primarily transmitted by mosquitoes. The enzootic transmission cycle typically involves a variety of bird species and mosquitoes that preferentially feed upon them. The main enzootic vectors in Québec are mosquitoes in the genus Culex (i.e., Culex pipiens and Cx. restuans). Cases of WNV occur sporadically each year in Québec and little is known about the factors that drive the magnitude of human outbreaks. Despite many studies on West Nile Virus (WNV) in the US, including the reservoir role of bird species and the summer shifts of the Culex mosquito, feeding from birds to mammals, there have been few equivalent studies in the neighboring regions of Canada where WNV is endemic. Birds are considered the main hosts of WNV amplification and dispersion. In this study, we aim to determine the relative importance of different bird species in WNV transmission in southern Quebec. We focused on the East Atlantic migration corridor of different avian species (according to the Avibase database). Bird species were then sorted and selected according to : 1) rates of avian mortality from WNV reported in local surveillance data from the Canadian Wildlife Health Cooperative; 2) seroprevalence and reservoir competence for WNV in North America (from the literature); 3) local bird density estimates (from ebird data), and 4) data from a blood meal analysis study on Culex pipiens/Cx.restuans mosquitoes captured between 2008 and 2013 in Montreal region. The analysis generated a list of 67 bird species potentially involved in the circulation of WNV in our study area and hypotheses were generated regarding the relative contribution to WNV amplificationThis study will improve our understanding of the factors that may impact WNV circulation in southern Québec and will be useful to future modelling studies of enzootic WNV transmission.

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