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1.
Clin Chem ; 2020 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-32715310

RESUMO

BACKGROUND: With the gradual reopening of economies and resumption of social life, robust surveillance mechanisms should be implemented to control the ongoing COVID-19 pandemic. Unlike RT-qPCR, SARS-CoV-2 whole genome sequencing (cWGS) has the added advantage of identifying cryptic origins of the virus, and the extent of community-based transmissions versus new viral introductions, which can in turn influence public health policy decisions. However, the practical and cost considerations of cWGS should be addressed before it is widely implemented. METHODS: We performed shotgun transcriptome sequencing using RNA extracted from nasopharyngeal swabs of patients with COVID-19, and compared it to targeted SARS-CoV-2 genome amplification and sequencing with respect to virus detection, scalability, and cost-effectiveness. To track virus origin, we used open-source multiple sequence alignment and phylogenetic tools to compare the assembled SARS-CoV-2 genomes to publicly available sequences. RESULTS: We found considerable improvement in whole genome sequencing data quality and viral detection using amplicon-based target enrichment of SARS-CoV-2. With enrichment, more than 99% of the sequencing reads mapped to the viral genome compared to an average of 0.63% without enrichment. Consequently, an increase in genome coverage was obtained using substantially less sequencing data, enabling higher scalability and sizable cost reductions. We also demonstrated how SARS-CoV-2 genome sequences can be used to determine their possible origin through phylogenetic analysis including other viral strains. CONCLUSIONS: SARS-CoV-2 whole genome sequencing is a practical, cost-effective, and powerful approach for population-based surveillance and control of viral transmission in the next phase of the COVID-19 pandemic.

2.
Viruses ; 12(5)2020 05 10.
Artigo em Inglês | MEDLINE | ID: mdl-32397688

RESUMO

The COVID-19 pandemic is due to infection caused by the novel SARS-CoV-2 virus that impacts the lower respiratory tract. The spectrum of symptoms ranges from asymptomatic infections to mild respiratory symptoms to the lethal form of COVID-19 which is associated with severe pneumonia, acute respiratory distress, and fatality. To address this global crisis, up-to-date information on viral genomics and transcriptomics is crucial for understanding the origins and global dispersion of the virus, providing insights into viral pathogenicity, transmission, and epidemiology, and enabling strategies for therapeutic interventions, drug discovery, and vaccine development. Therefore, this review provides a comprehensive overview of COVID-19 epidemiology, genomic etiology, findings from recent transcriptomic map analysis, viral-human protein interactions, molecular diagnostics, and the current status of vaccine and novel therapeutic intervention development. Moreover, we provide an extensive list of resources that will help the scientific community access numerous types of databases related to SARS-CoV-2 OMICs and approaches to therapeutics related to COVID-19 treatment.


Assuntos
Betacoronavirus/fisiologia , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/terapia , Pneumonia Viral/epidemiologia , Pneumonia Viral/terapia , Infecções por Coronavirus/tratamento farmacológico , Infecções por Coronavirus/genética , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/prevenção & controle , Genômica , Humanos , Pandemias , Pneumonia Viral/genética , Pneumonia Viral/imunologia , Vacinas Virais/imunologia
3.
Emerg Infect Dis ; 26(5): 1019-1021, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32097111

RESUMO

We conducted a cross-sectional survey of Crimean-Congo hemorrhagic fever virus (CCHFV) in dromedary camels and attached ticks at 3 locations in the United Arab Emirates. Results revealed a high prevalence of CCHFV-reactive antibodies in camels and viral RNA in ticks and camel serum, suggesting the virus is endemic in this country.

4.
Malar J ; 19(1): 69, 2020 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-32050970

RESUMO

BACKGROUND: Passerine birds are frequently infected with diverse haemosporidian parasites. While infections are traditionally considered benign in wild birds, recent studies demonstrated mortalities of passerine species due to exo-erythrocytic development of the parasites, which can damage organs in affected hosts. However, exo-erythrocytic development remains insufficiently investigated for most haemosporidian species and thus little is known about the virulence of tissue stages in wild passerine birds. The aim of the present study was to investigate natural haemosporidian infections in deceased Eurasian blackbirds (Turdus merula) and song thrushes (Turdus philomelos) and to determine parasite burden and associated histological effects. METHODS: For molecular analysis, blood and tissue samples from 306 thrushes were screened for Plasmodium, Haemoproteus and Leucocytozoon parasites by nested PCR. For the detection of parasite stages in organ samples, tissue sections were subjected to chromogenic in situ hybridization (CISH) using genus- and species-specific probes targeting the rRNAs of parasites. Exo-erythrocytic parasite burden was semi-quantitatively assessed and histological lesions were evaluated in haematoxylin-eosin-stained sections. RESULTS: By PCR, 179 of 277 Eurasian blackbirds and 15 of 29 song thrushes were positive for haemosporidians. Parasites of all three genera were detected, with Plasmodium matutinum LINN1 and Plasmodium vaughani SYAT05 showing the highest prevalence. CISH revealed significant differences in exo-erythrocytic parasite burden between lineages in Eurasian blackbirds, with P. matutinum LINN1 frequently causing high exo-erythrocytic parasite burdens in various organs that were associated with histological alterations. Song thrushes infected with P. matutinum LINN1 and birds infected with other haemosporidian lineages showed mostly low exo-erythrocytic parasite burdens. Two Eurasian blackbirds infected with Leucocytozoon sp. TUMER01 showed megalomeronts in various organs that were associated with inflammatory reactions and necroses. CONCLUSION: This study suggests that P. matutinum LINN1, a common lineage among native thrushes, regularly causes high exo-erythrocytic parasite burdens in Eurasian blackbirds, which may result in disease and mortalities, indicating its high pathogenic potential. The findings further illustrate that the same parasite lineage may show different levels of virulence in related bird species which should be considered when assessing the pathogenicity of haemosporidian parasite species. Finally, the study provides evidence of virulent Leucocytozoon sp. TUMER01 infections in two Eurasian blackbirds caused by megalomeront formation.

5.
Expert Rev Anti Infect Ther ; 18(2): 145-154, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31914833

RESUMO

Introduction: West Nile virus (WNV) is a mosquito-borne human and animal pathogen with nearly worldwide distribution. In Europe, the virus is endemic with seasonal regional outbreaks that have increased in frequency over the last 10 years. A massive outbreak occurred across southern and central Europe in 2018 with the number of confirmed human cases increasing up to 7.2-fold from the previous year, and expanding to include previously virus-free regions.Areas covered: This review focuses on potential causes that may explain the 2018 European WNV outbreak. We discuss the role genetic, ecological, and environmental aspects may have played in the increased activity during the 2018 transmission season, summarizing the latest epidemiological and virological publications.Expert opinion: Optimal environmental conditions, specifically increased temperature, were most likely responsible for the observed outbreak. Other factors cannot be ruled out due to limited available information, including factors that may influence host/vector abundance and contact. Europe will likely experience even larger-scale outbreaks in the coming years. Increased surveillance efforts should be implemented with a focus on early-warning detection methods, and large-scale host and vector surveys should continue to fill gaps in knowledge.

6.
Transbound Emerg Dis ; 67(1): 298-307, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31505099

RESUMO

Usutu virus (USUV), a mosquito-borne flavivirus closely related to West Nile virus, emerged in Austria in 2001, when it caused a considerable mass-mortality of Eurasian blackbirds. Cases in birds increased until 2003 and quickly declined thereafter, presumably due to developing herd immunity. Since 2006, no further cases were recorded, until two blackbirds were tested positive in 2016. In Hungary, USUV first appeared in 2005 and has caused only sporadic infections since then. Initially, the only genetic USUV lineage found across both countries was Europe 1. This changed in 2015/2016, when Europe 2 emerged, which has since then become the prevalent lineage. Due to dispersal of these strains and introduction of new genetic lineages, USUV infections are now widespread across Europe. In 2009, the first cases of USUV-related encephalitis were described in humans, and the virus has been frequently detected in blood donations since 2016. To monitor USUV infections among the Austrian wild bird population in 2017/2018, 86 samples were investigated by RT-PCR. In 67 of them, USUV nucleic acid was detected (17 in 2017, 50 in 2018). The majority of succumbed birds were blackbirds, found in Vienna and Lower Austria. However, the virus also spread westwards to Upper Austria and southwards to Styria and Carinthia. In Hungary, 253 wild birds were examined, but only six of them were infected with USUV (five in 2017, one in 2018). Thus, in contrast to the considerable increase in USUV-associated bird mortality in Austria, the number of infections in Hungary declined after a peak in 2016. Except for one case of USUV lineage Africa 3 in Austria in 2017, Europe 2 remains the most prevalent genetic lineage in both countries. Since USUV transmission largely depends on temperature, which affects vector populations, climate change may cause more frequent USUV outbreaks in the future.

7.
Transbound Emerg Dis ; 67(3): 1189-1197, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31840920

RESUMO

We report details of the first seven equine cases of confirmed West Nile neuroinvasive disease in Austria. The cases presented during summer and autumn of 2016 (n = 2), 2017 (n = 3) and 2018 (n = 2). All horses showed gait abnormalities and 6 of 7 horses exhibited fasciculations and/or tremors, and we provide video recordings of these. Three horses also showed cranial nerve involvement. Following rapid improvement, three horses were discharged. Four horses were euthanized due to the severity of clinical signs and subjected to neuropathological examination. West Nile virus (WNV) lineage 2 nucleic acid was detected in 5 of 7 horses, and WNV-specific neutralizing antibodies in all 7 horses. In addition, serologic evidence of WNV infection was found in two out of fourteen in-contact horses. Horses may be considered a sentinel species for human WNV infections, integrating human and veterinary medicine and thus contributing to the one health concept.

8.
Viruses ; 11(11)2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31683893

RESUMO

Prevalence studies have demonstrated a global distribution of equine hepacivirus (EqHV), a member of the family Flaviviridae. However, apart from a single case of vertical transmission, natural routes of EqHV transmission remain elusive. Many known flaviviruses are horizontally transmitted between hematophagous arthropods and vertebrate hosts. This study represents the first investigation of potential EqHV transmission by mosquitoes. More than 5000 mosquitoes were collected across Austria and analyzed for EqHV ribonucleic acid (RNA) by reverse transcription quantitative polymerase chain reaction (RT-qPCR). Concurrently, 386 serum samples from horses in eastern Austria were analyzed for EqHV-specific antibodies by luciferase immunoprecipitation system (LIPS) and for EqHV RNA by RT-qPCR. Additionally, liver-specific biochemistry parameters were compared between EqHV RNA-positive horses and EqHV RNA-negative horses. Phylogenetic analysis was conducted in comparison to previously published sequences from various origins. No EqHV RNA was detected in mosquito pools. Serum samples yielded an EqHV antibody prevalence of 45.9% (177/386) and RNA prevalence of 4.15% (16/386). EqHV RNA-positive horses had significantly higher glutamate dehydrogenase (GLDH) levels (p = 0.013) than control horses. Phylogenetic analysis showed high similarity between nucleotide sequences of EqHV in Austrian horses and EqHV circulating in other regions. Despite frequently detected evidence of EqHV infection in Austrian horses, no viral RNA was found in mosquitoes. It is therefore unlikely that mosquitoes are vectors of this flavivirus.

9.
Microorganisms ; 7(10)2019 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-31614950

RESUMO

Lednice virus (LEDV) has been detected in Culex modestus mosquitoes in several European countries within the last six decades. In this study, phylogenetic analyses of the complete genome segments confirm that LEDV belongs to the Turlock orthobunyavirus (Orthobunyavirus, Peribunyaviridae) species and is closely related to Umbre, Turlock, and Kedah viruses.

10.
Emerg Infect Dis ; 25(6): 1050-1057, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31107223

RESUMO

West Nile virus (WNV) and Usutu virus (USUV) circulate in several European Union (EU) countries. The risk of transfusion-transmitted West Nile virus (TT-WNV) has been recognized, and preventive blood safety measures have been implemented. We summarized the applied interventions in the EU countries and assessed the safety of the blood supply by compiling data on WNV positivity among blood donors and on reported TT-WNV cases. The paucity of reported TT-WNV infections and the screening results suggest that blood safety interventions are effective. However, limited circulation of WNV in the EU and presumed underrecognition or underreporting of TT-WNV cases contribute to the present situation. Because of cross-reactivity between genetically related flaviviruses in the automated nucleic acid test systems, USUV-positive blood donations are found during routine WNV screening. The clinical relevance of USUV infection in humans and the risk of USUV to blood safety are unknown.


Assuntos
Doadores de Sangue , Segurança do Sangue , União Europeia , Infecções por Flavivirus/epidemiologia , Flavivirus , Febre do Nilo Ocidental/epidemiologia , Vírus do Nilo Ocidental , Transfusão de Sangue , Doenças Transmissíveis Emergentes/epidemiologia , Europa (Continente)/epidemiologia , Infecções por Flavivirus/prevenção & controle , Infecções por Flavivirus/transmissão , Infecções por Flavivirus/virologia , Humanos , Incidência , Vigilância em Saúde Pública , Febre do Nilo Ocidental/prevenção & controle , Febre do Nilo Ocidental/transmissão , Febre do Nilo Ocidental/virologia
12.
Transbound Emerg Dis ; 66(4): 1701-1708, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30985075

RESUMO

Tick-borne encephalitis virus (TBEV) and West Nile virus (WNV) are important arthropod-borne zoonotic flaviviruses. Due to the emergence of WNV in TBEV-endemic regions co-circulation of both viruses is increasing. Flaviviruses are structurally highly similar, which leads to cross-reacting antibodies upon infection. Currently available serological assays for TBEV and WNV infections are therefore compromised by false-positive results, especially in IgG measurements. In order to discriminate both infections novel diagnostic methods are needed. We describe an ELISA to measure IgG antibodies specific for TBEV and WNV, applicable to human and horse sera. Mutant envelope proteins were generated, that lack conserved parts of the fusion loop domain, a predominant target for cross-reacting antibodies. These were incubated with equine and human sera with known TBEV, WNV or other flavivirus infections. For WNV IgG, specificities and sensitivities were 100% and 87.9%, respectively, for horse sera, and 94.4% and 92.5%, respectively, for human sera. TBEV IgG was detected with specificities and sensitivities of 95% and 96.7%, respectively, in horses, and 98.9% and 100%, respectively, in humans. Specificities increased to 100% by comparing individual samples on both antigens. The antigens could form the basis for serological TBEV- and WNV-assays with improved specificities.


Assuntos
Vírus da Encefalite Transmitidos por Carrapatos/isolamento & purificação , Encefalite Transmitida por Carrapatos/diagnóstico , Encefalite Transmitida por Carrapatos/veterinária , Doenças dos Cavalos/diagnóstico , Febre do Nilo Ocidental/diagnóstico , Febre do Nilo Ocidental/veterinária , Vírus do Nilo Ocidental/isolamento & purificação , Animais , Anticorpos Antivirais/análise , Cavalos , Humanos , Imunoglobulina G/análise
13.
Parasit Vectors ; 12(1): 153, 2019 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-30944019

RESUMO

BACKGROUND: In the last 50 years, the United Arab Emirates (UAE) has experienced rapid population growth and urbanization. Urbanization is known to influence biodiversity, and there appears to be a link between the emergence of arboviruses and urban growth. Very little is known about the UAE mosquito species richness and dominant vectors. We performed a mosquito survey comparing peri-urban sites in Dubai and Al Ain to a protected, natural site in Fujairah emirate. We measured mosquito biodiversity and species composition, and screened mosquito pools for common arboviruses to measure arbovirus activity in the region. RESULTS: We report ten species of mosquitoes from the UAE, with highest species diversity in the natural site, a protected wadi near the eastern coast. The predominant mosquito was Culex perexiguus, and was associated with peri-urban habitats. The site with lowest mosquito species diversity but relatively high species richness was the peri-urban site of Al Ain Zoo, where we identified Bagaza virus and Barkedji virus, two flaviviruses, in pools of Cx. perexiguus. CONCLUSIONS: Decreased mosquito biodiversity was associated with increased levels of urbanization. The predominance of two species at peri-urban sites was related to the availability of their larval habitats. Arboviruses were associated with the presence of a single predominant mosquito species, Cx. perexiguus.


Assuntos
Arbovirus/isolamento & purificação , Culicidae , Animais , Arbovirus/classificação , Biodiversidade , Culicidae/classificação , Culicidae/virologia , Feminino , Masculino , Mosquitos Vetores/virologia , Emirados Árabes Unidos , Urbanização
14.
Parasit Vectors ; 12(1): 46, 2019 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-30665453

RESUMO

BACKGROUND: The emergence of Usutu virus (USUV) in Europe was first reported in Austria, 2001, and the virus has since spread to many European countries. Initial outbreaks are marked by a mass die-off of European blackbirds (Turdus merula) and other bird species. During outbreaks, the virus has been detected in pools of Culex pipiens mosquitoes, and these mosquitoes are probably the most important enzootic vectors. Beginning in 2017, a second wave of blackbird deaths associated with USUV was observed in eastern Austria; the affected areas expanded to the Austrian federal states of Styria in the south and to Upper Austria in the west in 2018. We sampled the potential vector population at selected sites of bird deaths in 2018 in order to identify infected mosquitoes. RESULTS: We detected USUV RNA in 16 out of 19 pools of Cx. pipiens/Cx. torrentium mosquitoes at sites of USUV-linked blackbird mortality in Linz and Graz, Austria. A disseminated virus infection was detected in individuals from selected pools, suggesting that Cx. pipiens form pipiens was the principal vector. In addition to a high rate of infected Cx. pipiens collected from Graz, a disseminated virus infection was detected in a pool of Aedes japonicus japonicus. CONCLUSIONS: We show herein that naturally-infected mosquitoes at foci of USUV activity are primarily Cx. pipiens form pipiens. In addition, we report the first natural infection of Ae. j. japonicus with USUV, suggesting that it may be involved in the epizootic transmission of USUV in Europe. Ae. j. japonicus is an invasive mosquito whose range is expanding in Europe.


Assuntos
Aedes/virologia , Culex/virologia , Infecções por Flavivirus/transmissão , Flavivirus/fisiologia , Mosquitos Vetores/virologia , Animais , Monitoramento Epidemiológico , Feminino , Infecções por Flavivirus/epidemiologia , Infecções por Flavivirus/virologia , Humanos , Espécies Introduzidas
15.
Arch Virol ; 164(4): 1233-1244, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30663023

RESUMO

In October 2018, the order Mononegavirales was amended by the establishment of three new families and three new genera, abolishment of two genera, and creation of 28 novel species. This article presents the updated taxonomy of the order Mononegavirales as now accepted by the International Committee on Taxonomy of Viruses (ICTV).


Assuntos
Mononegavirais/classificação , Mononegavirais/genética , Mononegavirais/isolamento & purificação , Filogenia , Virologia/organização & administração
16.
Artigo em Inglês | MEDLINE | ID: mdl-30599276

RESUMO

Peptidomic analysis of norepinephrine-stimulated skin secretions from the Greek stream frog Rana graeca Boulenger, 1891 led to the identification and structural characterization of a range of host-defense peptides. These comprised brevinin-1GRa, brevinin-1GRb and an N-terminally extended form of brevinin-1GRb, ranatuerin-2GR together with its oxidized form and (11-28) fragment, temporin-GRa, temporin-GRb and its non-amidated form, and a melittin-related peptide, MRP-GR and its (1-18) fragment. The most abundant peptide, MRP-GR significantly (P < 0.001) stimulated insulin release from BRIN-BD11 clonal ß-cells at concentrations ≥0.1 nM. Rana graeca (formerly Rana graeca graeca) and the morphologically similar Italian stream frog Rana italica Dubois, 1987 (formerly Rana graeca italica) were originally regarded as sub-species. However, the primary structures of the host defense peptides from both frogs support the claim based upon comparisons of the nucleotide sequences of S1 satellite DNA that R. graeca and R. italica are separate species. Cladistic analyses based upon the primary structures of the brevinin-1 and ranatuerin-2 peptides from Eurasian frogs indicate a close phylogenetic relationship between R. graeca and Rana latastei whereas R. italica is most closely related to Rana dalmatina.


Assuntos
Proteínas de Anfíbios/metabolismo , Peptídeos/metabolismo , Filogenia , Ranidae/classificação , Pele/metabolismo , Sequência de Aminoácidos , Proteínas de Anfíbios/química , Animais , Linhagem Celular , Cromatografia Líquida de Alta Pressão , Cromatografia de Fase Reversa , Insulina/metabolismo , Peptídeos/química , Ranidae/metabolismo , Ratos , Especificidade da Espécie , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
17.
Syst Biol ; 68(5): 828-839, 2019 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-30597118

RESUMO

The International Committee on Taxonomy of Viruses (ICTV) is tasked with classifying viruses into taxa (phyla to species) and devising taxon names. Virus names and virus name abbreviations are currently not within the ICTV's official remit and are not regulated by an official entity. Many scientists, medical/veterinary professionals, and regulatory agencies do not address evolutionary questions nor are they concerned with the hierarchical organization of the viral world, and therefore, have limited use for ICTV-devised taxa. Instead, these professionals look to the ICTV as an expert point source that provides the most current taxonomic affiliations of viruses of interests to facilitate document writing. These needs are currently unmet as an ICTV-supported, easily searchable database that includes all published virus names and abbreviations linked to their taxa is not available. In addition, in stark contrast to other biological taxonomic frameworks, virus taxonomy currently permits individual species to have several members. Consequently, confusion emerges among those who are not aware of the difference between taxa and viruses, and because certain well-known viruses cannot be located in ICTV publications or be linked to their species. In addition, the number of duplicate names and abbreviations has increased dramatically in the literature. To solve this conundrum, the ICTV could mandate listing all viruses of established species and all reported unclassified viruses in forthcoming online ICTV Reports and create a searchable webpage using this information. The International Union of Microbiology Societies could also consider changing the mandate of the ICTV to include the nomenclature of all viruses in addition to taxon considerations. With such a mandate expansion, official virus names and virus name abbreviations could be catalogued and virus nomenclature could be standardized. As a result, the ICTV would become an even more useful resource for all stakeholders in virology.


Assuntos
Classificação/métodos , Virologia/métodos , Vírus/classificação , Cooperação Internacional , Virologia/normas , Virologia/tendências
18.
Euro Surveill ; 23(43)2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30376913

RESUMO

Between 28 June and 17 September 2018, 27 cases of human West Nile virus infections were recorded in Austria; four cases of West Nile neuroinvasive disease, 11 cases of West Nile fever, six infections detected by blood donation screening and six imported cases. In addition, 18 cases of human Usutu virus infections (all blood donors) were recorded. This is the highest number of annual infections recorded in Austria since the introduction of both viruses.


Assuntos
Notificação de Doenças , Infecções por Flavivirus/diagnóstico , Flavivirus/isolamento & purificação , Febre do Nilo Ocidental/diagnóstico , Vírus do Nilo Ocidental/isolamento & purificação , Áustria/epidemiologia , Infecções por Flavivirus/epidemiologia , Humanos , Febre do Nilo Ocidental/epidemiologia
19.
Vet Microbiol ; 222: 39-45, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30080671

RESUMO

West Nile virus (WNV; genus Flavivirus; family Flaviviridae) is the aetiological agent of an emerging, mosquito-borne disease with great impact on human and animal health. Over the past 15 years, WNV has been responsible for large epidemics mainly in North America but also in Europe, where lineage 1 and more recently lineage 2 strains have caused an upsurge in the number of outbreaks with increased human infection and higher virulence for certain wild bird species. This study aimed to compare the course of infection of the lineage 1 WNV strains Israel/98 and Italy/08 and the lineage 2 strain Austria/08 in the red-legged partridge (Alectoris rufa), a gallinaceous bird indigenous to the Iberian Peninsula and widely distributed in Southern and Western Europe. After experimental inoculation, clinical and analytic parameters (viraemia, viral load, antibodies) were examined over a period of 15 days. All inoculated birds became viremic and showed clinical disease, with a morbidity rate of 100% and mortality rates between 22.2 and 55.5% depending on the virus strain. The red-legged partridge demonstrated to be a competent host for transmission of the three investigated WNV isolates with the highest competence index observed for the Italian strain. Likewise, this strain was the most pathogenic causing the highest viral loads in blood, organs, feathers and oral and cloacal secretions. These experimental results indicate that the red-legged partridge is highly susceptible to the infection with lineage 1 and 2 WNV strains and that this species may act as an amplifying host for both WNV lineages.


Assuntos
Doenças das Aves/epidemiologia , Interações Hospedeiro-Patógeno , Codorniz/virologia , Febre do Nilo Ocidental/veterinária , Vírus do Nilo Ocidental/isolamento & purificação , Animais , Anticorpos Antivirais , Áustria/epidemiologia , Doenças das Aves/mortalidade , Doenças das Aves/transmissão , Doenças das Aves/virologia , Europa (Continente)/epidemiologia , Humanos , Israel/epidemiologia , Itália/epidemiologia , Carga Viral , Viremia , Febre do Nilo Ocidental/epidemiologia , Febre do Nilo Ocidental/mortalidade , Febre do Nilo Ocidental/virologia , Vírus do Nilo Ocidental/patogenicidade
20.
Parasit Vectors ; 11(1): 456, 2018 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-30081963

RESUMO

BACKGROUND: Uranotaenia unguiculata Edwards, 1913 is a species of mosquito (Diptera: Culicidae) native to central Europe. Recently a novel lineage of the West Nile virus (WNV-lineage 4c) was identified in pools of adult female Ur. unguiculata. To increase the body of knowledge about this species, various trapping methods were evaluated to determine the most efficient method for capturing adult female Ur. unguiculata. RESULTS: Sound traps collected equivalent numbers of female Ur. unguiculata as low-hanging light-baited downdraft traps. Hosts were identified as Pelophylax lessonae and P. ridibunda (Anura: Ranidae) species group frogs from the blood found in engorged females. In addition to confirming infection by WNV-lin. 4c, a potentially integrated flavivirus sequence was detected in male mosquitoes. A novel Alphamesonivirus 1 (Nidovirales: Mesoniviridae) was found to be widespread in the Ur. unguiculata population and is herein described. CONCLUSIONS: Efficient collection methods for Ur. unguiculata for arbovirus surveillance reflect mosquito questing behavior. Uranotaenia unguiculata targets frog species which call from the water, and it is likely that the novel WNV-lin. 4c is maintained in a frog-mosquito transmission cycle. The improved trapping methods listed here will assist future studies of the vector status of Ur. unguiculata for WNV and other arboviruses.


Assuntos
Anfíbios , Culicidae/fisiologia , Comportamento Alimentar , Som , Vírus/classificação , Animais , Culicidae/virologia , Feminino , Masculino , Fenômenos Fisiológicos Virais
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