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  • 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.
11

Estudo de arboviroses em pacientes positivos para malária da região Amazônica

Santana, Vinícius dos Santos [UNESP] 09 March 2010 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:27:20Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-03-09Bitstream added on 2014-06-13T19:35:17Z : No. of bitstreams: 1 santana_vs_me_sjrp.pdf: 385683 bytes, checksum: ccbda8f1740d544806e6c55fd2801145 (MD5) Bitstreams deleted on 2014-12-01T14:49:48Z: santana_vs_me_sjrp.pdf,Bitstream added on 2014-12-01T14:50:25Z : No. of bitstreams: 1 000610662.pdf: 4780545 bytes, checksum: 6398f15b690bb94e2d25e5daa3b06e45 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A região Amazônica apresenta extensas áreas de floresta e ecossistemas naturais, provendo condições favoráveis para a existência de muitos arbovírus. Mais de 200 arbovírus foram isolados na região Amazônica, e aproximadamente 40 estão associados a doenças humanas. Quatro dos 40 são considerados ser de importância para a saúde pública no Brasil: vírus da Dengue (sorotipos 1 a 4), Oropouche, Mayaro e Febre Amarela. Juntamente com os arbovírus, a malária é uma doença endêmica, e aproximadamente 98% dos casos estão restritos á região da Amazônia Legal. Este trabalho teve como objetivo analisar 111 amostras clínicas de soro de pacientes que residiam em Novo Repartimento (Pará), Porto Velho (Rondônia), Plácido de Castro (Acre) e Oiapoque (Amapá) previamente confirmados para malária. Para tal finalidade, foi utilizada a técnica de Multiplex-Nested-PCR e RT-Nested-PCR para a detecção e identificação dos principais arbovírus brasileiros, pertencentes aos gêneros Flavivirus, Alphavirus e Orthobunyavirus. Duas amostras de pacientes de Novo Repartimento foram positivas para Dengue sorotipo 2, e também, ambos tinham infecção por Plasmodium vivax . Apesar de dados escassos, infecções duplas por dengue e malária deveriam ser comuns em áreas onde ambas as doenças são co-endêmicas em muitas partes do mundo. Na região Amazônica Brasileira, esta situação provavelmente ocorre mais frequentemente que a detectada. Apesar de ambas as doenças causarem sintomas similares, e infecções simultâneas com dois agentes etiológicos podem resultar em uma doença com sintomas sobrepostos, e possivelmente, tanto o espectro clínico da doença e/ou o tratamento pode ser afetado. Neste contexto uma coinfecção por malaria e dengue não poderia ser descartada, e o diagnóstico deveria ser realizado concomitantemente para dengue e malária... / The Amazon region has extensive forested areas and natural ecosystems, providing suitable conditions to the existence of several aboviruses. Over 200 arboviruses were isolated in the Amazon region, and about 40 are associated to human diseases. Four out of 40 are considered to be of public health importance in Brazil: dengue virus (serotypes 1-4), Oropouche, Mayaro and Yellow Fever. Along with aboviruses, malaria is an endemic disease caused by protozoans Plasmodium falciparum, Plasmodium vivax and Plasmodium malariae in Brazil, and about 98% of the cases are restricted to the Legal Amazon region. The aim of this study was to test 99 serum clinical samples from patients living in Novo Repartimento (Pará), Porto Velho (Rondônia), Plácido de Castro (Acre) and 12 plasma samples from patients living in Oiapoque (Amapá), previously confirmed for malaria. For this purpose, we used Multiplex-Nested-PCR and RT-Nested-PCR assays for detection and identification of the major Brazilian arboviruses, belonging to the genus Flavivirus, Alphavirus and Orthobunyavirus. We detected Dengue virus serotype 2 in two serum samples from patients living in Novo Repartimento, and both had active Plasmodium vivax infections. Despite scant data, dual dengue and malaria dual infections should be common in areas where both diseases are co-endemic in many places of the world. In the Amazon region, this situation is likely to occur more frequently than detected. In spite of having similar clinical findings, and simultaneous infections with two etiological agents can result in a disease with overlapped symptoms, possibly either clinical spectrum of the disease or treatment can be affected. In this context, concurrent dengue and malaria could not be ruled out, and diagnosis should be made concomitantly in febrile patients living or returning from areas where both diseases are co-endemic... (Complete abstract click electronic access below)
12

Emergences virales en Afrique de l’ouest, dynamique et modélisation, l’exemple des arboviroses émergentes et ré-émergentes dans l'écosystème de Kédougou, Sénégal / Viral emergence in West Africa, dynamics and modeling, the example of emerging and re-emerging arboviruses in the ecosystem of Kedougou, Senegal

Sow, Abdourahmane 22 December 2017 (has links)
Au Sénégal, la région de Kédougou située au sud-est du pays est considérée comme une zone sentinelle d’endémie pour les arbovirus. Le modèle en est représenté par le virus de la Fièvre jaune (VFJ) qui circule à bas bruit avec des amplifications périodiques tous les 4 à 6 ans. Cependant, peu de données sont à ce jour produites sur les déterminants de la dynamique d'émergence des arboviroses d’importance humaine dans la région. Ainsi, la région de Kédougou a été marquée depuis le début des années 2000 par un développement socio-économique et démographique remarquable qui compte parmi les facteurs anthropiques susceptibles de modifier la diffusion des arboviroses dans la région. Notre travail de recherche a évalué la dynamique des arboviroses émergentes et ré-émergentes dans l’écosystème de Kédougou. Pour ce faire, nous avons mis en place un système de surveillance multidisciplinaire (épidémiologique, entomologique et virologique), réalisé une étude de séroprévalence de l’infection par l’arbovirus Chikungunya (CHIKV) et produit une analyse par modélisations afin d’identifier les facteurs environnementaux et anthropiques liés à la dynamique des émergences arbovirales dans la région. Ce système de surveillance sentinelle a permis la détection d’amplifications du cycle selvatique du CHIKV et VFJ en 2009 et 2011, avec la circulation de ces deux virus chez l’homme (notamment 20 cas de Chikungunya en 2009 et 13 cas confirmés et 10 cas probables de fièvre jaune en 2011). L’adaptation au contexte domestique du moustique vecteur Aedes aegypti, l’urbanisation non contrôlée, la migration massive des populations ainsi que le mouvement des troupeaux de bétails ont été retrouvés comme facteurs pouvant contribuer à l’émergence et à la propagation des arbovirus au Sénégal et dans la région de Kédougou ainsi que dans le reste du Sénégal. Ce modèle d’observatoire multidisciplinaire associé aux outils de modélisation, au système d’information géographique et au développement de l’épidémiologie moléculaire et de la génomique devrait être étendu à d’autres pays de la région d’Afrique de l’Ouest pour renforcer la surveillance et anticiper l’émergence des épidémies en permettant la mise en place de stratégies de prévention et de contrôle pragmatiques et évolutives. / Located in southeastern Senegal, the Kedougou region is considered as an endemic zone for arboviruses with periodic amplifications every 4 to 6 years, as foreseen for the dynamic of the infection by the yellow fever virus (YFV). However, few data are available on the human specific circulation concern for arboviruses in humans in the region. In addition, the Kedougou region has been marked since the early 2000’s by a considerable socio-economic and demographic development that is to be addressed for changing the spreading of arboviruses with human concern in the area. Our research aimed to assess the dynamic of the circulation of emerging and re-emerging arboviruses in the ecosystem of Kedougou, southeastern Senegal, located close to the border of Mali and Guinea. Hence, we have set up a multidisciplinary (epidemiological, entomological and virological) sentinel surveillance system, carried out a CHIKV seroprevalence study and finally carried out modeling studies in to identify environmental determinants related to the emergence of arboviruses in the region. This system has detected an amplification of CHIKV and YFV sylvatic cycle respectively in 2009 and 2011 associated with a human circulation of these viruses with 20 identified cases of Chikungunya in 2009 and 13 confirmed and 10 probable cases of yellow fever in 2011. Concurrently, adaptation to the domestic context of the Aedes aegypti mosquito competent vector, uncontrolled urbanization, massive migration of populations as well as the movement of livestock have been found as potential factors contributing to the emergence and spreading of arboviruses. This multidisciplinary observatory model combined with mathematical modeling tools, geographic information system and the development of molecular epidemiology and genomics should be extended to other West African countries to strengthen the arboviruses surveillance and anticipate the emergence of epidemics through the implementation of prevention and effective control strategies.
13

Caracterización molecular de cepas aisladas de dengue 2 en Perú; 2000-2010

Cruz Malpica, Cristhopher Donat's January 2013 (has links)
El virus Dengue (VDEN) es el responsable de más de 50-100 millones de casos anualmente en el mundo. La infección del dengue es causada por cuatro serotipos (VDEN-1, VDEN-2, VDEN-3 y VDEN-4) y el espectro de la enfermedad varía desde una fiebre indiferenciada, fiebre hemorrágica por dengue (FHD), síndrome de shock por dengue, y muerte. Información epidemiológica liga el desarrollo de FHD con una infección secundaria y además sugiere que ciertas cepas son más virulentas que otras. En 2001, aparecieron los primeros casos de FHD asociados con VDEN-2 en la costa del Perú. En el 2010 ocurrió un brote en Iquitos con casos severos convirtiéndose en el más largo en la historia de la región. Sin embargo estudios orientados en determinar el origen distribución y diversidad genética de cepas peruanas de VDEN-2 durante los diez últimos años no han sido realizados. Para atender este vacío de conocimiento en la epidemiología del VDEN-2 en Perú, extractos de ARN de 30 aislamientos virales en células C6/36 (Aedes albopictus) fueron procesados por RT-PCR. Secuencias del gen de la envoltura (E) fueron determinadas y comparadas con muestras globales de VDEN-2. El análisis filogenético reveló la circulación de dos genotipos en Perú: Americano (hasta el 2000) y Americano/Asiático (2000- 2010). Adicionalmente se identificaron cepas variantes del genotipo Americano/Asiático distribuidos en dos clados principales (1 y 2) que ingresaron al Perú por la costa norte (Ecuador) y por la selva (Brasil o Bolivia). Con el aparente incremento de la virulencia relacionada a cepas Americano/Asiático del clado 2, nuestros resultados soportan la necesidad de un continuo monitoreo de cepas emergentes de nuevos variantes o genotipos de dengue que podrían estar asociados a casos severos de la enfermedad. Palabras claves: Arbovirus, Dengue 2, Americano/Asiático y relación filogenética.
14

Dengue diagnosis in an endemic area of Peru: Clinical characteristics and positive frequencies by RT-PCR and serology for NS1, IgM, and IgG

Palomares-Reyes, Carlos, Silva-Caso, Wilmer, del Valle, Luis J., Aguilar-Luis, Miguel Angel, Weilg, Claudia, Martins-Luna, Johanna, Viñas-Ospino, Adriana, Stimmler, Luciana, Mallqui Espinoza, Naysha, Aquino Ortega, Ronald, Espinoza Espíritu, Walter, Misaico, Erika, del Valle-Mendoza, Juana 04 1900 (has links)
This work was supported by Cienciativa of CONCYTEC Peru, under contract number 164-2016-FONDECYT, and the Programa Nacional de Innovación para la Competitividad y Productividad (Innóvate Perú), under contract number 116-PNICP-PIAP-2015. / Background: Huánuco is a central eastern region of Peru whose geography includes high forest and low jungle, as well as a mountain range that constitutes the inter-Andean valleys. It is considered a region endemic for dengue due to the many favorable conditions that facilitate transmission of the virus. Methods: A total of 268 serum samples from patients in Huánuco, Peru with an acute febrile illness were assessed for the presence of dengue virus (DENV) via RT-PCR and NS1, IgM, and IgG ELISA during December 2015 and March 2016. Results: DENV was detected in 25% of samples via RT-PCR, 19% of samples by NS1 antigen ELISA, and 10.5% of samples by IgM ELISA. DENV IgG was detected in 15.7% of samples by ELISA. The most frequent symptoms associated with fever across all groups were headache, myalgia, and arthralgia, with no significant difference between the four test methods Conclusions: In this study, DENV was identified in up to 25% of the samples using the standard laboratory method. In addition, a correlation was established between the frequency of positive results and the serological tests that determine NS1, IgM, and IgG. There is an increasing need for point-of-care tests to strengthen epidemiological surveillance in Peru. / Revisión por pares / Revisión por pares
15

Estudo das interações entre proteínas de Groundnut ringspot virus (Bunyaviridae: Tospovirus)

Lima, Rayane Nunes 24 February 2014 (has links)
Dissertação (mestrado)—Universidade de Brasília, Instituto de Ciências Biológicas, Programa de Pós-Graduação em Biologia Molecular, 2014. / Submitted by Jaqueline Ferreira de Souza (jaquefs.braz@gmail.com) on 2014-05-27T13:14:11Z No. of bitstreams: 1 2014_RayaneNunesLima_Parcial.pdf: 885295 bytes, checksum: 3a9506e71c4557a00fffa96f5fd2010f (MD5) / Approved for entry into archive by Patrícia Nunes da Silva(patricia@bce.unb.br) on 2014-06-05T13:45:39Z (GMT) No. of bitstreams: 1 2014_RayaneNunesLima_Parcial.pdf: 885295 bytes, checksum: 3a9506e71c4557a00fffa96f5fd2010f (MD5) / Made available in DSpace on 2014-06-05T13:45:39Z (GMT). No. of bitstreams: 1 2014_RayaneNunesLima_Parcial.pdf: 885295 bytes, checksum: 3a9506e71c4557a00fffa96f5fd2010f (MD5) / Groundnut ringspot virus (GRSV) pertence ao gênero Tospovirus, o único da família de arbovírus Bunyaviridae capaz de infectar vegetais, sendo transmitido por tripes (Thysanoptera: Thripidae) de maneira circulativa propagativa. O genoma dos tospovírus é constituído por três segmentos de RNA fita simples denominados RNA S (Small), RNA M (Medium) e RNA L (Large). O RNA L codifica uma RNA polimerase dependente de RNA (RdRp); o RNA S codifica a proteína do nucleocapsídeo (N) e a proteína supressora do silenciamento gênico (NSs); e o RNA M codifica a proteína precursora das glicoproteínas Gn e Gc e a NSm, proteína de movimento viral célula-a-célula. As interações proteicas entre N e NSm são importantes para a disseminação da infecção viral na planta. Para a movimentação viral em plantas infectadas é necessária a oligomerização da proteína NSm, que forma túbulos que penetram os plasmodesmas celulares e promovem a passagem dos ribonucleocapsídeos virais de uma célula a outra. Os ribonucleocapsídeos são formados pela RNA polimerase viral (RdRp) e pelos segmentos de RNA (S, M e L) envolvidos pela nucleoproteína (N), que se oligomeriza para encapsidar todo o RNA viral. O presente trabalho investigou, pela primeira vez, as interações entre a proteína N e NSm de GRSV através da técnica de Fluorescência Bimolecular Complementar, bem como evidenciou a localização subcelular citoplasmática de cada interação. Um modelo tridimensional para a proteína N de GRSV foi construído in silico, por modelagem estrutural por homologia molecular, a partir das estruturas secundária e terciária da proteína N de LACV (La Crosse virus; Orthobunyavirus), e os domínios funcionais para a interação N x N e interação N x RNA foram definidos. A proteína N de GRSV apresenta um braço N-terminal (aa 1-32), um braço C-terminal (aa 224-258) e uma região globular com uma cavidade contendo resíduos de aminoácidos hidrofóbicos e positivos para a interação com o RNA. O alinhamento de sequências de aminoácidos da proteína N de todos os Tospovírus já caracterizados mostrou que os resíduos de aminoácidos preditos como chave para a conformação e interação da proteína N são conservados entre as espécies. Juntas, essas evidências abrem caminho para novos estudos acerca das interações proteicas a fim de elucidar o movimento célula-a-célula do GRSV e de outros Tospovírus. / Groundnut ringspot virus (GRSV) belongs to the genus Tospovirus, the only plant-infecting genus of the family Bunyaviridae, being transmitted by thrips (Thysanoptera: Thripidae) in a circulative propagative manner. The genome of tospoviruses consists of three single stranded RNA segments, termed S RNA (small) M RNA (Medium) and L RNA (Large). The L RNA encodes an RNA dependent RNA polymerase (RdRp). The S RNA encodes the nucleocapsid protein (N) and a gene silencing suppressor protein (NSs). The M RNA encodes the precursor protein of the Gn and Gc glycoproteins and the NSm protein, a viral cell-to-cell movement protein. Protein interactions between N and NSm are important to the viral infection spread in the plant. The NSm oligomerizes to form tubules that penetrate through plasmodesmata allowing the passage of viral ribonucleocapsids promoting cell-to-cell viral movement. The ribonucleocapsids are formed by the viral RNA polymerase (RdRp) and the RNA segments (S, M and L) surrounded by the nucleoprotein (N), which oligomerizes to encapsidate the viral RNA. This study investigated for the first time, homotypic and heterotypic interactions between N and NSm of the GRSV by Bimolecular Fluorescence Complementation (BiFC) in planta and showed the cytoplasmic subcellular localization of each interaction. A three-dimensional model for N GRSV protein was constructed in silico, by molecular homology modeling, from secondary and tertiary protein structures of N LACV (La Crosse virus; Orthobunyavirus) and the functional domains for N x N interaction and N x RNA interaction were defined. N GRSV protein presents an N-terminal arm (aa 1-32), a C- terminal arm (aa 224-258) and a globular region with a groove containing hydrophobic and positive amino acid residues for interaction with RNA. The alignment of amino acid sequences of the N protein of all characterized tospoviruses has shown that the amino acid residues important to protein fold and interaction of the N protein are conserved among all species. Together, this evidence allows further studies about the protein interactions involved to the cell-to-cell movement for GRSV and for other tospoviruses.
16

Detection of dengue virus serotype 3 in Cajamarca, Peru: Molecular diagnosis and clinical characteristics

Aguilar-Luis, Miguel, Carrillo-Ng, Hugo, Kym, Sungmin, Silva-Caso, Wilmer, Verne, Eduardo, Del Valle, Luis, Bazn-Mayra, Jorge, Zavaleta-Gavidia, Victor, Cornejo-Pacherres, Daniel, Tarazona-Castro, Yordi, Aquino-Ortega, Ronald, Cornejo-Tapia, Angela, Valle-Mendoza, Juana 01 October 2021 (has links)
Objective: To describe and molecularly characterize an outbreak of dengue virus (DENV) infection in Cajamarca, an Andean region in Peru. Methods: A total of 359 serum samples from patients with acute febrile illness were assessed for the presence of DENV via RT-PCR, ELISA NS1, IgM and IgG in Cajamarca, Peru from January 2017 to June 2017. The evaluation of the different diagnostic tests and their applicability was performed. Results: Dengue virus was detected in 24.7% of samples by RTPCR. Meanwhile, serological analysis detected 30.3% positive cases via ELISA NS1 antigen, 16.7% via ELISA IgG and 9.7% via ELISA IgM. Most of the cases corresponded to DENV-3 (77.5%). The use of RT-PCR performed better in primary infections (P<0.01), while detection of ELISA IgM performed better in secondary infections (P<0.01). The combination of NS1 and IgM performed better than the other assays in detecting primary (92.5%) and secondary infections (96.6%). The most frequent symptoms associated with fever were headaches, myalgias, and arthralgias across all groups. Conclusions: We report an important outbreak of dengue infection caused by DENV-3 in Cajamarca, Peru. Our findings encourage the use of NS1 antigen and IgM co-detection. These findings demonstrate an increasing expansion of DENV-3 in Peru and highlight the importance of molecular diagnosis and serotype characterization among the clinically defined dengue cases to strengthen the Peruvian epidemiological surveillance. / Ministry of Health and Welfare / Revisión por pares
17

INTRACELLULAR RNAS FOUND DURING BUNYAVIRUS INFECTIONS (RECOMBINANT, DNA, VIROLOGY).

Spriggs, Melanie Kay January 1984 (has links)
The family Bunyaviridae is the largest known taxonomic group of arboviruses. Four of the five genera possess members which are responsible for serious human and livestock disease. The worldwide distribution of these viruses justify studies which will allow understanding of the replication and transcription cycles within permissive cells. The bunyaviruses have been shown to possess a tripartite single strand RNA genome of negative polarity. Replication is confined to the cytoplasm and the virion envelope is acquired when the genome ribonucleoproteins bud into the golgi. Virus release is presumed to be through exocytosis and ultimately cell lysis. The messenger RNA species of all five genera do not possess a poly-A tail of sufficient length to bind to an oligo(dT) cellulose column. This has made separation of viral transcripts from replicating RNAs difficult. In an effort to achieve this separation, infected cell extracts were centrifuged over 20-40% CsCl gradients which permitted replicating RNA structures to band at a density of 1.32 while cellular and viral mRNAs pellet. Recovery of viral transcripts from the CsCl pelleted RNA required synthesis of a cDNA copy of the virus genome to use as a probe. This was done by an unusual method which employs both genome and antigenomic RNA as templates for reverse transcriptase in a first strand synthesis reaction. Recombinant viral clones were then used in a hybrid selection scheme to recover virus mRNA from pelleted material. After recovery, the messages were visualized on acid urea agarose gels pH 3.5, or used to program an in vitro translation reaction. Using these methods, it was established that each genome segment codes for a single messenger RNA which is most likely capped, and that for at least the mid sized segment, proteins with molecular weights which exceed the coding capacity of the genome are translated from the single message.
18

The ecology and epidemiology of arboviruses in South Africa with reference to their arthropod vectors.

Jupp, Peter Graham January 1992 (has links)
Published work submitted to the Faculty of Medicine, University of the Witwatersrand, Johannesburg, for the degree Doctor of Science in Medicine. / Andrew Chakane 2018
19

Aspectos epidemiológicos da encefalite por arbovirus na região do Vale do Ribeira, São Paulo, Brasil, no período de 1975 a 1978 / Epidemiological aspects of encephalitis caused by arbovirus in the Ribeira Valley region, São Paulo, Brazil, in 1975 and 1978

Iversson, Lygia Busch 18 May 1979 (has links)
Foi realizado um estudo epidemiológico da epidemia de encefalite por arbovírus na região do Vale do Ribeira, São Paulo, Brasil, durante o período de março de 1975 a julho de 1978. A epidemia, iniciada em 1975, atingiu o pico em 1976. A partir de 1978 a moléstia se manteve em níveis baixos sob presumível endemicidade. A letalidade nos anos epidêmicos de 1976 e 1977 variou em sentido inverso ao da morbidade, que apresentou picos nas épocas de maior temperatura e pluviosidade. Ao que parece, a epidemia teria se deslocado em onda em direção leste-oeste e leste-sudoeste tendo atingido a região litorânea vizinha. A cadeia montanhosa situada ao norte e noroeste teria atuado como barreira à propagação da moléstia. Considerou-se a hipótese que o agente etiológico, arbovírus Rocio, só recentemente deva ter começado a infectar a população humana, tendo sido veiculado ao homem a partir de reservatórios silvestres, aves e pequenos mamíferos, por culicídeos silvestres. Discutiram-se também prováveis formas de transmissão domiciliar da arbovirose ocorrida em número bem menor de casos. Verificou-se que os grupos populacionais que apresentaram as formas mais graves da doença foram os das idades extremas e os de piores condições de vida. Considerou-se que a perspectiva epidemiológica desta arbovirose é que ela persista na região, uma vez que existem condições ótimas para o desenvolvimento dO agente etiológico, de reservatórios e de vetores biológicos, além do contínuo afluxo de população suscetível, constituída por migrantes ou por turistas. / An epidemiological study of the encephalitis epidemic by arbovirus was carried out in Ribeira River Valley, State of São Paulo, Brazil, from March 1975 to July 1978. The epidemic began in 1975 and reached its peak in 1976. From 1978 onwards the disease maintained low levels in a presurnable endemicity. The lethality of the disease in the epidemic years of 1976 and 1977 varied in the opposite direction of its morbility, which presented peaks when the temperature and pluvial levels were higher. It seems that the epidemic swept from east to west and from east to southwest in a wave towards the neighbouring coastland region. The mountain chain situated towards the north and northwest acted as a barrier to the spreading of the disease. The hypothesis that the etiological agent, arbovirus Rocio, must have infected the human population recently, having been veiculated to man from forest reservoirs, birds and small mammals, by wild mosquitoes, was considered. Probable forms of domiciliar transmission of the arbovirosis which ocurred in a significantly smaller number of cases were also discussed. It was verified that the population groups which presented the worst forms of the disease were those at extreme ages and those under worst living conditions. It was considered that the epidemiological perspective of the arbovirosis is that it ought to persist in the area, as it presents excellent conditions for the development of the etiological agent, reservoirs and biological vectors, besides continuously receiving susceptible people, migrants or tourists.
20

Detecció d'arbovirus en vectors a Espanya

Aranda Pallero, Carlos 30 June 2010 (has links)
Entre els anys 2001 i 2005 es van capturar i analitzar 72.895 femelles de mosquits (Diptera: Culicidae) i 6.871 de flebòtoms (Diptera: Psychodidae) en les estacions d'abundància amb l'objectiu de detectar la presència de genoma d'arbovirus en diferents àrees d'Espanya, en especial en zones humides. L'estudi forma part d'un de més general que tracta de la transmissió d'arbovirus en quatre dels aiguamolls més importants d'Espanya que es troben a Girona, Barcelona, Tarragona i Huelva.Els insectes es van recollir amb esquer humà, amb trampes de CO2 i amb trampes CDC i es van agrupar en pools segons la data de captura, la localitat i l'espècie. Pel que fa als flebòtoms, les mostres es van obtenir a partir del 2002 a Barcelona i Huelva i es van identificar com a subfamília.Els culícids es van agrupar en 4.723 pools i pertanyien a 20 espècies dels gèneres Anopheles, Aedes, Ochlerotatus, Culex, Culiseta, Coquillettidia i Uranotaenia i els flebòtoms es van agrupar en 236 pools com a tals.Mentre es duia a terme l'estudi, es va detectar el mosquit invasor -Aedes (Stegomyia) albopictus (Skuse)- per primera vegada a Espanya, concretament a Sant Cugat del Vallès, durant l'estiu del 2004. Mitjançant inspeccions immediatament posteriors es va comprovar l'existència d'importants poblacions a la zona, i se'n va confirmar l'establiment. Aquesta és la primera notificació de l'espècie esmentada a la península Ibèrica. Es van analitzar totes les femelles capturades posteriorment a l'àrea d'estudi.L'espècie de culícid més abundant va ser Ochlerotatus caspius (40,9 %), seguida de Culex pipiens (32,3 %), Culex theileri (10,9 %), Anopheles atroparvus (6,6 %), i Culex modestus (4,6 %).Es van analitzar homogenats dels vectors per detectar directament ARN d'arbovirus dels gèneres Alphavirus, Flavivirus i Phlebovirus. No s'ha trobat ARN d'arbovirus patògens coneguts. En el cas dels mosquits, 111 pools van ser positius a Flavivirus, l'únic gènere detectat en aquest grup taxonòmic. Les seqüències de Flavivirus identificades són diferents de qualsevol Flavivirus de mosquit conegut i majoritàriament properes al virus Kamiti River (KRV) o al virus cell fusing agent (CFA), excepte en dos pools d'Andalusia que es troben properes al grup de virus transmesos per artròpodes. Per a totes les zones i espècies, es va calcular l'estimació del màxim de versemblança de la taxa d'infecció o the maximum likelihood estimation infection rate (MLE). Ae. albopictus tingué la MLE més alta, de 47,14, seguida per Aedes vexans amb 43,67 en el conjunt de l'àrea d'estudi. Per sota d'aquestes espècies hi havia Culiseta annulata, amb 36,00. Les espècies més abundants, Oc. caspius i Cx. pipiens, va obtenir valors MLE baixos (0,94 i 0,38 respectivament) en el conjunt de tota l'àrea.En el cas dels flebòtoms, 10 pools (9 dels quals de Barcelona) van donar positiu a Flavivirus semblants a Culex Flavivirus (CxFV). És la primera vegada que es troba genoma d'aquest gènere en flebòtoms de fora de l'Àfrica. En 8 pools de Barcelona es va trobar un Phlebovirus similar al complex Nàpols i al virus Massilia.Cal assenyalar que en el cas d'alguns mosquits, en especial en mostres dels gèneres Aedes i Ochlerotatus, el genoma detectat probablement eren seqüències d'ADN integrades en el genoma dels mosquits. Aquest fet l'han observat recentment altres autors.El 2006, seguint amb la campanya de detecció d'arbovirus, es va trobar, entre 436 pools dels aiguamolls de Catalunya i 9 espècies de mosquit, un de positiu a un Flavivirus identificat com a virus Usutu (USUV) en un pool de 3 Cx. pipiens obtingut a Viladecans (Barcelona). Les dades d'homologia van mostrar que la soca espanyola pertanyia a l'USUV però que era més propera a mostres africanes d'USUV que a les obtingudes a Europa central. / With the aim of assessing the presence of arbovirus genome in vectors in different areas, especially wetlands, in Spain, a total of 72,895 female mosquitoes (Diptera: Culicidae) and 6,871 sandflies (Diptera: Psychodidade) were trapped during their season of abundance, and analyzed between the years 2001 and 2005. The study formed part of general arbovirus transmission research in four of the most important wetlands in Spain in the provinces of Girona, Barcelona, Tarragona, and Huelva.Insects were collected using human bait, CO2 traps, or light traps, and they were pooled according to date of collection, location, and species. In the case of sandflies, the period of study started in 2002 in Barcelona and Huelva and species were not identified. Mosquitoes were sorted into 4,723 pools belonging to 20 Culicidae species from the Anopheles, Aedes, Ochlerotatus, Culex, Culiseta, Coquillettidia, and Uranotaenia genera. Sandflies were sorted into 236 pools as a whole.During the study, the invasive mosquito Aedes (Stegomyia) albopictus (Skuse) was detected for the first time in Spain, in Sant Cugat del Vallès during August 2004. Dense populations of adults and larvae were found in subsequent surveys, confirming the establishment of this species in this area. This is the first report of the establishment of Ae. albopictus in the Iberian Peninsula. All captured females in the studied area belonging to this species were analyzed.The most abundant species was Ochlerotatus caspius (40.9 %), followed by Culex pipiens (32.3 %), Culex theileri (10.9 %), Anopheles atroparvus (6.6 %), and Culex modestus (4.6 %).Arboviral RNA was directly detected from vector homogenates for the genera Alphavirus, Flavivirus, and Phlebovirus. No arboviral RNA from known pathogenic arboviruses was found. In the case of mosquitoes, 111 pools tested positive for unknown mosquito Flavivirus, the only genus detected in this taxonomic group. The Flavivirus sequences identified were different from all known Flavivirus mosquito viruses, but very close to Kamiti River virus (KRV) or cell fusing agent virus (CFA) with the exception of two pools from Andalusia, close to the group of arthropod borne viruses. The maximum likelihood estimation infection rate (MLE) was calculated for all regions and species. Ae. albopictus had the highest MLE at 47.14, followed by Aedes vexans with 43.67 over the entire area. These species were followed by Culiseta annulata, with 36.00. The most common species, Oc. caspius and Cx. pipiens, had low MLE values -0.94 and 0.38, respectively- over the area as a whole.In the case of sandflies, 10 pools (9 in Barcelona) tested positive for a Flavivirus similar to Culex Flavivirus (CxFV) being this, the first time that Flavivirus genome is detected in sand flies outside Africa. Phlebovirus viruses similar to Naples complex and Massilia were found in 8 sandflies pools, all from Barcelona area.In some samples of mosquitoes, especially in genera Aedes and Ochlerotatus, detected genome was probably DNA sequences integrated in the mosquito genome as has been observed recently by other authors.In 2006, surveillance monitoring samples carried out in Catalonia detected, in 436 pools belonging to 9 mosquito species, a positive for Flavivirus identified as Usutu virus (USUV) in a pool of 3 Cx. pipiens obtained from the town of Viladecans, Barcelona. The homology data showed that the Spanish strain belongs to USUV species and is more related to the African USUV isolates than to central European isolates.

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