Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 62
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Arch Virol ; 165(1): 87-96, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31707455

RESUMO

In May 2017, high mortality of chickens and Muscovy ducks due to the H5N8 highly pathogenic avian influenza virus (HPAIV) was reported in the Democratic Republic of Congo (DR Congo). In this study, we assessed the molecular, antigenic, and pathogenic features in poultry of the H5N8 HPAIV from the 2017 Congolese outbreaks. Phylogenetic analysis of the eight viral gene segments revealed that all 12 DR Congo isolates clustered in clade 2.3.4.4B together with other H5N8 HPAIVs isolated in Africa and Eurasia, suggesting a possible common origin of these viruses. Antigenically, a slight difference was observed between the Congolese isolates and a representative virus from group C in the same clade. After intranasal inoculation with a representative DR Congo virus, high pathogenicity was observed in chickens and Muscovy ducks but not in Pekin ducks. Viral replication was higher in chickens than in Muscovy duck and Pekin duck organs; however, neurotropism was pronounced in Muscovy ducks. Our data confirmed the high pathogenicity of the DR Congo virus in chickens and Muscovy ducks, as observed in the field. National awareness and strengthening surveillance in the region are needed to better control HPAIVs.


Assuntos
Antígenos Virais/metabolismo , Vírus da Influenza A Subtipo H5N8/classificação , Vírus da Influenza A Subtipo H5N8/patogenicidade , Influenza Aviária/imunologia , Doenças das Aves Domésticas/virologia , África , Animais , Ásia , Galinhas , República Democrática do Congo , Patos/classificação , Patos/virologia , Europa (Continente) , Sequenciamento de Nucleotídeos em Larga Escala , Vírus da Influenza A Subtipo H5N8/genética , Vírus da Influenza A Subtipo H5N8/isolamento & purificação , Influenza Aviária/virologia , Filogenia , Filogeografia , Doenças das Aves Domésticas/imunologia , Especificidade da Espécie , Replicação Viral
2.
Artigo em Inglês | MEDLINE | ID: mdl-31174704

RESUMO

During 2014-2017 Clade 2.3.4.4 H5N8 highly pathogenic avian influenza viruses (HPAIVs) have spread worldwide. In 2016, an epidemic of HPAIV H5N8 in Iran caused mass deaths among wild birds, and several commercial poultry farms and captive bird holdings were affected and continue to experience problems. Several outbreaks were reported in 2017. One of them is related to Hooded crow (Corvus cornix) in a national park in Esfahan province in 2017. Whole genome sequencing and characterization have been done on the detected H5N8 sample. Based on HA sequencing results, it belongs to 2.3.4.4 clade, and the cleavage site is (PLREKRRKR/G). Phylogenetic analysis of the HA gene showed that the Iran 2017 H5N8 virus clustered within subgroup Russia 2016 2.3.4.4 b of group B in H5 clade 2.3.4.4 HPAIV. On the other hand, the NA gene of the virus is placed in group C of Eurasian lineage. Complete genome characterization of this virus revealed probable reassortment of the virus with East-Asian low-pathogenic influenza viruses. Furthermore, the virus possessed some phenotypic markers related to the increased potential for transmission and pathogenicity to mammals at internal segments. This study is the first full genome characterization H5N8 HPAIV in Iran. The data complete the puzzle of molecular epidemiology of H5N8 HPAIV in Iran and the region. Our study provides evidence for fast and continuing reassortment of H5 clade 2.3.4.4 viruses, that might lead to changes in virus structural and functional characteristics such as the route and method of transmission of the virus and virus infective, pathogenic and zoonotic potential.


Assuntos
Corvos/virologia , Genoma Viral , Vírus da Influenza A Subtipo H5N8/genética , Influenza Aviária/epidemiologia , Influenza Aviária/virologia , Animais , Surtos de Doenças , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Vírus da Influenza A Subtipo H5N8/isolamento & purificação , Irã (Geográfico)/epidemiologia , Mutação , Filogenia , RNA Viral/genética , Vírus Reordenados/genética , Vírus Reordenados/isolamento & purificação
3.
Transbound Emerg Dis ; 66(3): 1370-1378, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30874364

RESUMO

In the Netherlands, three commercial poultry farms and two hobby holdings were infected with highly pathogenic avian influenza (HPAI) H5N6 virus in the winter of 2017-2018. This H5N6 virus is a reassortant of HPAI H5N8 clade 2.3.4.4 group B viruses detected in Eurasia in 2016. H5N6 viruses were also detected in several dead wild birds during the winter. However, wild bird mortality was limited compared to the caused by the H5N8 group B virus in 2016-2017. H5N6 virus was not detected in wild birds after March, but in late summer infected wild birds were found again. In this study, the complete genome sequences of poultry and wild bird viruses were determined to study their genetic relationship. Genetic analysis showed that the outbreaks in poultry were not the result of farm-to-farm transmissions, but rather resulted from separate introductions from wild birds. Wild birds infected with viruses related to the first outbreak in poultry were found at short distances from the farm, within a short time frame. However, no wild bird viruses related to outbreaks 2 and 3 were detected. The H5N6 virus isolated in summer shares a common ancestor with the virus detected in outbreak 1. This suggests long-term circulation of H5N6 virus in the local wild bird population. In addition, the pathogenicity of H5N6 virus in ducks was determined, and compared to that of H5N8 viruses detected in 2014 and 2016. A similar high pathogenicity was measured for H5N6 and H5N8 group B viruses, suggesting that biological or ecological factors in the wild bird population may have affected the mortality rates during the H5N6 epidemic. These observations suggest different infection dynamics for the H5N6 and H5N8 group B viruses in the wild bird population.


Assuntos
Surtos de Doenças/veterinária , Epidemias/veterinária , Vírus da Influenza A/genética , Influenza Aviária/epidemiologia , Doenças das Aves Domésticas/epidemiologia , Animais , Animais Selvagens , Aves , Vírus da Influenza A Subtipo H5N8/genética , Vírus da Influenza A Subtipo H5N8/isolamento & purificação , Vírus da Influenza A Subtipo H5N8/patogenicidade , Vírus da Influenza A/isolamento & purificação , Vírus da Influenza A/patogenicidade , Influenza Aviária/virologia , Países Baixos/epidemiologia , Aves Domésticas , Doenças das Aves Domésticas/virologia , Sequenciamento Completo do Genoma/veterinária
4.
Poult Sci ; 98(6): 2371-2379, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-30668795

RESUMO

A total of 50 poultry farms of commercial broilers (N = 39) and commercial layers (N = 11) suffered from respiratory problems and mortality during the period from January 2016 to December 2017 were investigated. Also, samples were collected from quail (N = 4), Bluebird (Sialis, N = 1), and Greenfinch (Chloris chloris, N = 1) for analysis. Respiratory viral pathogens were screened by PCR and positive samples were subjected to virus isolation and genetic identification. Antigenic relatedness of isolated avian influenza (AI) H5 subtype was evaluated using cross-hemagglutination inhibition. Results revealed that the incidence of single virus infections in commercial broilers was 64.1% (25/39), with the highest incidence for ND (33.3%) and H9N2 (20.5%), followed by H5N1 (7.7%) and H5N8 (2.7). Meanwhile, H9N2/ND mixed infection was the most observed case (7.7%). Other mixed infections H5N1/ND, H5N1/H9N2/ND, H5N1/H9N2/ND/IB, H9N2/IB, and H9N2/ILT were also observed (2.6% each). In commercial layers, H5N1 and ILT were the only detected single infections (18.1% each). Mixed H9N2/ND was the most predominant infection in layers (27.3%). Other mixed infections of H9N2/IB, H5N1/H5N8/H9N2, and H9N2/ND/IB were observed in 3 separate farms (9.1% each). The H5N8 virus was detected in one quail farm and 2 out of 3 wild bird's samples. Partial HA gene sequence analysis showed the clustering of the selected AI H5N8 within the 2.3.4.4 clade, while H5N1 clustered with the clade 2.2.1.2. Interestingly, the H5N8 isolated from chickens possessed 6 amino acids substitutions at HA1 compared to those isolated from wild birds with low antigenic relatedness to AI H5N1 clades 2.2.1 or 2.2.1.2. In conclusion, mixed viral infections were observed in both broiler and layer chickens in Egypt. The detected triple H5N1, H9N2, and H5N8 influenza co-infection raises the concern of potential AI epidemic strain emergence. The low genetic and antigenic relatedness between AI H5N1 and H5N8 viruses suggest the need for modification of vaccination strategies of avian influenza in Egypt along with strict biosecurity measures.


Assuntos
Doenças das Aves/epidemiologia , Coinfecção/veterinária , Influenza Aviária/epidemiologia , Doenças das Aves Domésticas/epidemiologia , Animais , Animais Selvagens , Doenças das Aves/virologia , Galinhas , Coinfecção/epidemiologia , Coinfecção/virologia , Coturnix , Egito/epidemiologia , Tentilhões , Incidência , Virus da Influenza A Subtipo H5N1/genética , Virus da Influenza A Subtipo H5N1/imunologia , Virus da Influenza A Subtipo H5N1/fisiologia , Vírus da Influenza A Subtipo H5N8/genética , Vírus da Influenza A Subtipo H5N8/imunologia , Vírus da Influenza A Subtipo H5N8/fisiologia , Influenza Aviária/virologia , Doenças das Aves Domésticas/virologia , Prevalência , Aves Canoras
6.
Sci Rep ; 8(1): 18037, 2018 12 21.
Artigo em Inglês | MEDLINE | ID: mdl-30575785

RESUMO

Between October 2016 and December 2017, several European Countries had been involved in a massive Highly Pathogenic Avian Influenza (HPAI) epidemic sustained by H5N8 subtype virus. Starting on December 2016, also Italy was affected by H5N8 HPAI virus, with cases occurring in two epidemic waves: the first between December 2016 and May 2017, and the second in July-December 2017. Eighty-three outbreaks were recorded in poultry, 67 of which (80.72%) occurring in the second wave. A total of 14 cases were reported in wild birds. Epidemiological information and genetic analyses were conjointly used to get insight on the spread dynamics. Analyses indicated multiple introductions from wild birds to the poultry sector in the first epidemic wave, and noteworthy lateral spread from October 2017 in a limited geographical area with high poultry densities. Turkeys, layers and backyards were the mainly affected types of poultry production. Two genetic sub-groups were detected in the second wave in non-overlapping geographical areas, leading to speculate on the involvement of different wild bird populations. The integration of epidemiological data and genetic analyses allowed to unravel the transmission dynamics of H5N8 virus in Italy, and could be exploited to timely support in implementing tailored control measures.


Assuntos
Aves/virologia , Vírus da Influenza A Subtipo H5N8/genética , Influenza Aviária/transmissão , Influenza Aviária/virologia , Aves Domésticas/virologia , Animais , Animais Selvagens/virologia , Busca de Comunicante/veterinária , Surtos de Doenças/veterinária , Epidemias , Testes Genéticos/veterinária , Genótipo , Vírus da Influenza A Subtipo H5N8/classificação , Influenza Aviária/epidemiologia , Itália/epidemiologia , Filogenia , Doenças das Aves Domésticas/epidemiologia , Doenças das Aves Domésticas/transmissão , Doenças das Aves Domésticas/virologia , Integração de Sistemas , Virulência/genética
7.
Vet Microbiol ; 227: 127-132, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30473343

RESUMO

Reported mass mortalities in wild pigeons and doves during the 2017/2018 Clade 2.3.4.4 HPAI H5N8 outbreaks in South Africa necessitated an investigation of healthy racing pigeons for their susceptibility and ability to transmit a Clade 2.3.4.4 sub-group B virus of South African origin. Pigeons challenged with medium (104.5 EID50) and high doses (106 EID50) but not a low dose (103 EID50) of virus, shed virus in low levels of <103 EID50/ml from the oropharynx and cloaca for up to eight days, with peak shedding around 4 days post challenge. Challenged pigeons were able to transmit the virus to contact pigeons, but not contact chickens. Neither pigeons nor chickens presented clinical disease, and only two pigeons in the group that received the high challenge dose developed influenza A-virus specific antibodies. The levels of virus shed by the racing pigeons were well below the published bird infectious dose 50 values for most poultry, especially chickens, therefore the risk that racing pigeons could act as propagators and disseminators through excretion of Clade 2.3.4.4 HPAI H5N8 strains remains negligible.


Assuntos
Doenças das Aves/virologia , Columbidae/virologia , Surtos de Doenças/veterinária , Vírus da Influenza A Subtipo H5N8/patogenicidade , Influenza Aviária/virologia , Doenças das Aves Domésticas/virologia , Animais , Anticorpos Antivirais , Doenças das Aves/mortalidade , Doenças das Aves/transmissão , Galinhas , Surtos de Doenças/estatística & dados numéricos , Vírus da Influenza A Subtipo H5N8/classificação , Vírus da Influenza A Subtipo H5N8/genética , Vírus da Influenza A Subtipo H5N8/isolamento & purificação , Influenza Aviária/mortalidade , Influenza Aviária/transmissão , Doenças das Aves Domésticas/mortalidade , Doenças das Aves Domésticas/patologia , África do Sul , Eliminação de Partículas Virais
8.
Infect Genet Evol ; 66: 269-271, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30342095

RESUMO

In early January 2017, outbreaks of H5N8 highly pathogenic avian influenza (HPAI) were reported for the first time in wild and domestic birds along the shores and on some islands of Lake Victoria, in central-southern Uganda. Our whole-genome phylogenetic analyses revealed that the H5N8 viruses recovered from the outbreak in Uganda belonged to genetic clade 2.3.4.4 group-B and clustered with viruses collected in 2017 in the Democratic Republic of the Congo and in West Africa. Our results suggested that infected migratory wild birds might have played a crucial role in the introduction of HPAI H5N8 into this region.


Assuntos
Animais Selvagens , Aves , Vírus da Influenza A Subtipo H5N8/genética , Influenza Aviária/epidemiologia , Influenza Aviária/virologia , Animais , Animais Selvagens/virologia , Aves/virologia , Surtos de Doenças , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Vírus da Influenza A Subtipo H5N8/classificação , Vírus da Influenza A Subtipo H5N8/patogenicidade , Filogenia , Uganda/epidemiologia
9.
Euro Surveill ; 23(26)2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29970219

RESUMO

IntroductionFrance is one of Europe's foremost poultry producers and the world's fifth largest producer of poultry meat. In November 2016, highly pathogenic avian influenza (HPAI) virus subtype H5N8 emerged in poultry in the country. As of 23 March 2017, a total of 484 confirmed outbreaks were reported, with consequences on animal health and socio-economic impacts for producers. Methods: We examined the spatio-temporal distribution of outbreaks that occurred in France between November 2016 and March 2017, using the space-time K-function and space-time permutation model of the scan statistic test. Results: Most outbreaks affected duck flocks in south-west France. A significant space-time interaction of outbreaks was present at the beginning of the epidemic within a window of 8 km and 13 days. This interaction disappeared towards the epidemic end. Five spatio-temporal outbreak clusters were identified in the main poultry producing areas, moving sequentially from east to west. The average spread rate of the epidemic front wave was estimated to be 5.5 km/week. It increased from February 2017 and was negatively associated with the duck holding density. Conclusion: HPAI-H5N8 infections varied over time and space in France. Intense transmission events occurred at the early stages of the epidemic, followed by long-range jumps in the disease spread towards its end. Findings support strict control strategies in poultry production as well as the maintenance of high biosecurity standards for poultry holdings. Factors and mechanisms driving HPAI spread need to be further investigated.


Assuntos
Surtos de Doenças/veterinária , Patos/virologia , Vírus da Influenza A Subtipo H5N8/patogenicidade , Influenza Aviária/epidemiologia , Doenças das Aves Domésticas/virologia , Animais , França , Vírus da Influenza A Subtipo H5N8/genética , Vírus da Influenza A Subtipo H5N8/isolamento & purificação , Influenza Aviária/virologia , Aves Domésticas/virologia , Doenças das Aves Domésticas/epidemiologia , Análise Espaço-Temporal
10.
Transbound Emerg Dis ; 65(6): 1664-1670, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29920971

RESUMO

Sixty-five poultry outbreaks and sixty-eight events in wild birds were reported during the highly pathogenic H5N8/H5N5 avian influenza epidemic in Poland in 2016-2017. The analysis of all gene segment sequences of selected strains revealed cocirculation of at least four different genome configurations (genotypes) generated through reassortment of clade 2.3.4.4 H5N8 viruses detected in Russia and China in mid-2016. The geographical and temporal distribution of three H5N8 genotypes indicates separate introductions. Additionally, an H5N5 virus with a different gene configuration was detected in wild birds. The compilation of the results with those from studies on the virus' diversity in Germany, Italy and the Netherlands revealed that Europe was affected by at least eight different H5N8/H5N5 reassortants. Analysis of the HA gene sequence of a larger subset of samples showed its diversification corresponding to the genotype classification. The close relationship between poultry and wild bird strains from the same locations observed in several cases points to wild birds as the primary source of the outbreaks in poultry.


Assuntos
Animais Selvagens/virologia , Surtos de Doenças/veterinária , Vírus da Influenza A Subtipo H5N8/genética , Influenza Aviária/virologia , Doenças das Aves Domésticas/virologia , Animais , Galinhas , Patos , Genótipo , Vírus da Influenza A Subtipo H5N8/isolamento & purificação , Vírus da Influenza A Subtipo H5N8/patogenicidade , Influenza Aviária/epidemiologia , Biologia Molecular , Filogenia , Polônia/epidemiologia , Doenças das Aves Domésticas/epidemiologia , Perus
12.
Infect Genet Evol ; 63: 144-150, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29852294

RESUMO

Highly pathogenic avian influenza viruses (HPAIV) A(H5N8) of group B (Gochang1-like) have emerged in the Tyva Republic of eastern Russia in May 2016. Since November 2016, HPAIV A(H5N8) has spread throughout the European part of Russia. Thirty-one outbreaks were reported in domestic, wild and zoo birds in 2017. The present study aimed to perform a comparative analysis of new HPAIV A(H5N8) strains. Phylogenetic analysis revealed four genetically distinct subgroups in HPAIV A(H5N8) from the 2016-2017 season. Russian strains consisted of three subgroups with differences between isolates from Tyva, Siberia (Chany Lake), and the European part of Russia. Strains from the European part of Russia showed the beginnings of divergent evolution. Slight differences of the Voronezh strains were suggested by sensitivity to antiviral compounds. Testing for host-specific mutations in sequenced strains revealed the absence of mutations associated with possible increased tropism/virulence in mammalian species, including humans. Only one residue of polymerase basic-1, 13P, is discussed, because the L13P mutation increased complementary RNA synthesis in mammalian cells. We concluded that the evolution of HPAIV A(H5N8) is continuous. Surveillance in Russia revealed new cases of HPAIV A(H5N8) and led to the elaboration of prevention strategies, which should be implemented.


Assuntos
Vírus da Influenza A Subtipo H5N8/genética , Vírus da Influenza A Subtipo H5N8/patogenicidade , Influenza Aviária/virologia , Animais , Antivirais/farmacologia , Aves , Cães , Farmacorresistência Viral , Evolução Molecular , Influenza Aviária/epidemiologia , Células Madin Darby de Rim Canino , Mutação , Federação Russa/epidemiologia
13.
Emerg Infect Dis ; 24(7): 1371-1374, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29912707

RESUMO

In 2017, highly pathogenic avian influenza A(H5N8) virus was detected in poultry in the Democratic Republic of the Congo. Whole-genome phylogeny showed the virus clustered with H5N8 clade 2.3.4.4B strains from birds in central and southern Asia. Emergence of this virus in central Africa represents a threat for animal health and food security.


Assuntos
Vírus da Influenza A Subtipo H5N8 , Influenza Aviária/epidemiologia , Influenza Aviária/virologia , Animais , Galinhas , República Democrática do Congo/epidemiologia , Patos , Geografia , História do Século XXI , Humanos , Vírus da Influenza A Subtipo H5N8/classificação , Vírus da Influenza A Subtipo H5N8/genética , Vírus da Influenza A Subtipo H5N8/patogenicidade , Influenza Humana/epidemiologia , Influenza Humana/história , Influenza Humana/virologia , Uganda/epidemiologia
15.
Emerg Microbes Infect ; 7(1): 67, 2018 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-29670093

RESUMO

Highly pathogenic avian influenza (HPAI) is essentially a poultry disease. Wild birds have traditionally not been involved in its spread, but the epidemiology of HPAI has changed in recent years. After its emergence in southeastern Asia in 1996, H5 HPAI virus of the Goose/Guangdong lineage has evolved into several sub-lineages, some of which have spread over thousands of kilometers via long-distance migration of wild waterbirds. In order to determine whether the virus is adapting to wild waterbirds, we experimentally inoculated the HPAI H5N8 virus clade 2.3.4.4 group A from 2014 into four key waterbird species-Eurasian wigeon (Anas penelope), common teal (Anas crecca), mallard (Anas platyrhynchos), and common pochard (Aythya ferina)-and compared virus excretion and disease severity with historical data of the HPAI H5N1 virus infection from 2005 in the same four species. Our results showed that excretion was highest in Eurasian wigeons for the 2014 virus, whereas excretion was highest in common pochards and mallards for the 2005 virus. The 2014 virus infection was subclinical in all four waterbird species, while the 2005 virus caused clinical disease and pathological changes in over 50% of the common pochards. In chickens, the 2014 virus infection caused systemic disease and high mortality, similar to the 2005 virus. In conclusion, the evidence was strongest for Eurasian wigeons as long-distance vectors for HPAI H5N8 virus from 2014. The implications of the switch in species-specific virus excretion and decreased disease severity may be that the HPAI H5 virus more easily spreads in the wild-waterbird population.


Assuntos
Animais Selvagens/virologia , Patos/virologia , Vírus da Influenza A Subtipo H5N8/isolamento & purificação , Vírus da Influenza A Subtipo H5N8/patogenicidade , Influenza Aviária/patologia , Eliminação de Partículas Virais , Migração Animal , Animais , Cloaca/virologia , Surtos de Doenças/veterinária , Monitoramento Epidemiológico , Vírus da Influenza A Subtipo H5N8/genética , Influenza Aviária/epidemiologia , Influenza Aviária/virologia , Filogenia
16.
Avian Pathol ; 47(4): 400-409, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29701481

RESUMO

In 2016, the highly pathogenic avian influenza (HPAI) H5N8 virus was detected in wild birds for the first time in Egypt. In the present study, we identified the HPAI virus H5N8 of clade 2.3.4.4 from domestic waterfowl in Egypt, suggesting its transmission to the domestic poultry from the migratory birds. Based on partial haemagglutinin gene sequence, this virus has a close genetic relationship with subtype H5N8 viruses circulating in Asia and Europe. Pathologically, H5N8 virus in hybrid duck induced nervous signs accompanied by encephalomalacia, haemorrhages, nonsuppurative encephalitis and nonsuppurative vasculitis. The granular layer of cerebellum showed multifocal areas of hydropic degeneration and the Purkinje cell neurons were necrotized or lost. Additionally, the lung, kidney and spleen were congested, and necrotizing pancreatitis was also observed. The co-circulation of both HPAI H5N1 and H5N8 subtypes with the low pathogenic avian influenza H9N2 subtype complicate the control of avian influenza in Egypt with the possibility of emergence of new reassortant viruses. Therefore, continuous monitoring with implementation of strict control measures is required. Research highlights HPAI H5N8 virus clade 2.3.4.4 was detected in domestic ducks and geese in Egypt in 2017. Phylogenetically, the virus was closely related to HPAI H5N8 viruses identified in Asia and Europe Nonsuppurative encephalitis was widely observed in HPAI H5N8 virus-infected ducks. Degeneration of the cerebellar granular layer was found in most of the brain tissues examined.


Assuntos
Patos/virologia , Gansos/virologia , Vírus da Influenza A Subtipo H5N8/isolamento & purificação , Influenza Aviária/virologia , Doenças das Aves Domésticas/virologia , Animais , Egito/epidemiologia , Vírus da Influenza A Subtipo H5N8/genética , Vírus da Influenza A Subtipo H5N8/imunologia , Vírus da Influenza A Subtipo H5N8/patogenicidade , Influenza Aviária/epidemiologia , Influenza Aviária/patologia , Filogenia , Doenças das Aves Domésticas/epidemiologia , Doenças das Aves Domésticas/patologia
17.
Arch Virol ; 163(8): 2219-2224, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29623433

RESUMO

Here, we present a comprehensive analysis of the H5N8/H5N5 highly pathogenic avian influenza (HPAI) virus strains detected in the Czech Republic during an outbreak in 2017. Network analysis of the H5 Hemagglutinin (HA) from 99% of the outbreak localities suggested that the diversity of the Czech H5N8/H5N5 viruses was influenced by two basic forces: local microevolution and independent incursions. The geographical occurrence of the central node H5 HA sequences revealed three eco-regions, which apparently played an important role in the origin and further spread of the local H5N8/HPAI variants across the country. A plausible explanation for the observed pattern of diversity is also provided.


Assuntos
Evolução Molecular , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Vírus da Influenza A Subtipo H5N8/genética , Vírus da Influenza A/genética , Influenza Aviária/virologia , Animais , Aves/classificação , Aves/virologia , República Tcheca/epidemiologia , Surtos de Doenças , Variação Genética , Vírus da Influenza A Subtipo H5N8/classificação , Vírus da Influenza A Subtipo H5N8/isolamento & purificação , Vírus da Influenza A Subtipo H5N8/patogenicidade , Vírus da Influenza A/classificação , Vírus da Influenza A/isolamento & purificação , Vírus da Influenza A/patogenicidade , Influenza Aviária/epidemiologia , Filogenia , Virulência
18.
Emerg Microbes Infect ; 7(1): 29, 2018 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-29535296

RESUMO

Highly pathogenic avian influenza (HPAI) A(H5N6) and A(H5N8) virus infections resulted in the culling of more than 37 million poultry in the Republic of Korea during the 2016/17 winter season. Here we characterize two representative viruses, A/Environment/Korea/W541/2016 [Em/W541(H5N6)] and A/Common Teal/Korea/W555/2017 [CT/W555(H5N8)], and evaluate their zoonotic potential in various animal models. Both Em/W541(H5N6) and CT /W555(H5N8) are novel reassortants derived from various gene pools of wild bird viruses present in migratory waterfowl arising from eastern China. Despite strong preferential binding to avian virus-type receptors, the viruses were able to grow in human respiratory tract tissues. Em/W541(H5N6) was found to be highly pathogenic in both chickens and ducks, while CT/W555(H5N8) caused lethal infections in chickens but did not induce remarkable clinical illness in ducks. In mice, both viruses appeared to be moderately pathogenic and displayed limited tissue tropism relative to HPAI H5N1 viruses. Em/W541(H5N6) replicated to moderate levels in the upper respiratory tract of ferrets and was detected in the lungs, brain, spleen, liver, and colon. Unexpectedly, two of three ferrets in direct contact with Em/W541(H5N6)-infected animals shed virus and seroconverted at 14 dpi. CT/W555(H5N8) was less pathogenic than the H5N6 virus in ferrets and no transmission was detected. Given the co-circulation of different, phenotypically distinct, subtypes of HPAI H5Nx viruses for the first time in South Korea, detailed virologic investigations are imperative given the capacity of these viruses to evolve and cause human infections.


Assuntos
Vírus da Influenza A Subtipo H5N8/patogenicidade , Vírus da Influenza A/patogenicidade , Influenza Aviária/virologia , Migração Animal , Animais , Animais Selvagens/virologia , Galinhas , China , Patos , Furões , Vírus da Influenza A Subtipo H5N8/genética , Vírus da Influenza A Subtipo H5N8/isolamento & purificação , Vírus da Influenza A Subtipo H5N8/fisiologia , Vírus da Influenza A/genética , Vírus da Influenza A/isolamento & purificação , Vírus da Influenza A/fisiologia , Influenza Aviária/epidemiologia , Influenza Aviária/patologia , Influenza Aviária/fisiopatologia , Doenças das Aves Domésticas/epidemiologia , Doenças das Aves Domésticas/patologia , Doenças das Aves Domésticas/fisiopatologia , Doenças das Aves Domésticas/virologia , Vírus Reordenados/classificação , Vírus Reordenados/genética , Vírus Reordenados/isolamento & purificação , Vírus Reordenados/patogenicidade , República da Coreia/epidemiologia , Estações do Ano , Virulência , Replicação Viral
19.
Euro Surveill ; 23(7)2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29463346

RESUMO

We investigated influenza A(H5N6) viruses from migratory birds in Chungnam and Gyeonggi Provinces, South Korea following a reported die-off of poultry in nearby provinces in November 2017. Genetic analysis and virulence studies in chickens and ducks identified our isolate from December 2017 as a novel highly pathogenic avian influenza virus. It resulted from reassortment between the highly virulent H5N8 strain from Korea with the N6 gene from a low-pathogenic H3N6 virus from the Netherlands.


Assuntos
Galinhas/virologia , Patos/virologia , Vírus da Influenza A Subtipo H5N8/genética , Vírus da Influenza A Subtipo H5N8/patogenicidade , Vírus da Influenza A/patogenicidade , Influenza Aviária/virologia , Vírus Reordenados , Virulência , Migração Animal , Animais , Surtos de Doenças/veterinária , Humanos , Vírus da Influenza A Subtipo H5N8/classificação , Vírus da Influenza A Subtipo H5N8/isolamento & purificação , Vírus da Influenza A/genética , Vírus da Influenza A/isolamento & purificação , Influenza Aviária/epidemiologia , Influenza Aviária/patologia , Países Baixos , Filogenia , Doenças das Aves Domésticas/epidemiologia , Doenças das Aves Domésticas/patologia , Doenças das Aves Domésticas/virologia , Vírus Reordenados/classificação , Vírus Reordenados/genética , Vírus Reordenados/isolamento & purificação , Vírus Reordenados/patogenicidade , República da Coreia/epidemiologia , Estações do Ano , Replicação Viral
20.
Emerg Infect Dis ; 24(5)2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29470165

RESUMO

After high mortality rates among commercial poultry were reported in Egypt in 2017, we genetically characterized 4 distinct influenza A(H5N8) viruses isolated from poultry. Full-genome analysis indicated separate introductions of H5N8 clade 2.3.4.4 reassortants from Europe and Asia into Egypt, which poses a serious threat for poultry and humans.


Assuntos
Vírus da Influenza A Subtipo H5N8/genética , Influenza Aviária/virologia , Doenças das Aves Domésticas/virologia , Aves Domésticas , Sequência de Aminoácidos , Animais , Biomarcadores , Egito/epidemiologia , Hemaglutininas/química , Hemaglutininas/genética , Hemaglutininas/metabolismo , Vírus da Influenza A Subtipo H5N8/patogenicidade , Influenza Aviária/epidemiologia , Filogenia , Doenças das Aves Domésticas/epidemiologia , Virulência
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA