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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.
Transbound Emerg Dis ; 66(3): 1301-1305, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30740920

RESUMO

European starlings (Sturnus vulgaris), house sparrows (Passer domesticus) and rock pigeons (Columba livia) are all wild birds commonly found in large numbers in and around human dwellings and domestic livestock operations. This study evaluated the susceptibility of these species to three strains of highly pathogenic avian influenza virus (HP AIV) clade 2.3.4.4 isolated in the U.S.. Experimental infection of European starlings and rock pigeons did not result in any overt signs attributable to AIV infection and no virus shedding was detected from the oral and cloacal routes. House sparrows shed by the oral route and exhibited limited mortality. Individuals from all three species seroconverted following infection. These data suggest that none of these birds are a likely potential bridge host for future HP AIV outbreaks but that their seroconversion may be a useful surveillance tool for detection of circulating H5 HP AIV.


Assuntos
Surtos de Doenças/veterinária , Reservatórios de Doenças/veterinária , Vírus da Influenza A Subtipo H5N2/isolamento & purificação , Vírus da Influenza A Subtipo H5N8/isolamento & purificação , Influenza Aviária/epidemiologia , Animais , Animais Selvagens , Aves , Columbidae , Reservatórios de Doenças/virologia , Humanos , Vírus da Influenza A Subtipo H5N2/imunologia , Vírus da Influenza A Subtipo H5N2/patogenicidade , Vírus da Influenza A Subtipo H5N8/imunologia , Vírus da Influenza A Subtipo H5N8/patogenicidade , Vírus da Influenza A Subtipo H5N8/fisiologia , Influenza Aviária/virologia , Soroconversão , Pardais , Estorninhos , Estados Unidos/epidemiologia , Eliminação de Partículas Virais
5.
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
6.
Viruses ; 10(9)2018 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-30205456

RESUMO

In contrast to previous incursions of highly pathogenic avian influenza (HPAIV) H5 viruses, H5N8 clade 2.3.4.4b viruses caused numerous cases of lethal infections in white-tailed sea eagles (Haliaeetus albicilla) affecting mainly young eagles (younger than five years of age) in Germany during winter 2016/2017. Until April 2017, 17 HPAIV H5N8-positive white-tailed sea eagles had been detected (three found alive and 14 carcasses) by real-time RT-PCR and partial nucleotide sequence analyses. Severe neurological clinical signs were noticed which were corroborated by immunohistopathology revealing mild to moderate, oligo- to multifocal necrotizing virus-induced polioencephalitis. Lethal lead (Pb) concentrations, a main factor of mortality in sea eagles in previous years, could be ruled out by atomic absorption spectrometry. HPAIV H5 clade 2.3.4.4b reportedly is the first highly pathogenic influenza virus known to induce fatal disease in European white-tailed see eagles. This virus strain may become a new health threat to a highly protected species across its distribution range in Eurasia. Positive cloacal swabs suggest that eagles can spread the virus with their faeces.


Assuntos
Águias/virologia , Vírus da Influenza A Subtipo H5N8/isolamento & purificação , Vírus da Influenza A Subtipo H5N8/patogenicidade , Influenza Aviária/mortalidade , Influenza Aviária/virologia , Animais , Encefalite/etiologia , Encefalite/patologia , Alemanha/epidemiologia , Imuno-Histoquímica , Influenza Aviária/epidemiologia , Influenza Aviária/patologia , Reação em Cadeia da Polimerase em Tempo Real , Análise de Sequência de DNA
7.
Transbound Emerg Dis ; 65(6): 1823-1827, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30014592

RESUMO

American robins (Turdus migratorius) are commonly associated with farmsteads in the United States and have shown previous evidence of exposure to an H5 avian influenza A virus (IAV) near a poultry production facility affected by a highly pathogenic (HP) H5 virus in Iowa, USA during 2015. We experimentally infected American robins with three clade 2.3.4.4 HP H5 viruses (H5N2 and H5N8). A total of 22/24 American robins shed virus, and all three strains were represented. The highest virus titres shed were 104.3 , 104.3 and 104.8 PFU/ml, associated respectively with viruses isolated from poultry, a captive gyrfalcon (Falco rusticolus), and a Northern pintail (Anas acuta). Of those birds that shed, viral shedding was initiated 1 or 2 days post-infection (DPI) and shedding ceased in all birds by 7 DPI. This study adds an additional synanthropic wildlife species to a growing list of animals that can successfully replicate and shed IAVs.


Assuntos
Vírus da Influenza A Subtipo H5N2/isolamento & purificação , Vírus da Influenza A Subtipo H5N8/isolamento & purificação , Influenza Aviária/virologia , Aves Canoras/virologia , Eliminação de Partículas Virais , Animais
8.
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
9.
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
11.
Arch Virol ; 163(10): 2675-2685, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29872951

RESUMO

This work aimed to analyze the herd immunity to influenza among a Russian population living in regions with an increased risk of emergence of viruses with pandemic potential, and to isolate and investigate virus strains from severe influenza cases, including fatal cases, during the 2016-2017 epidemic season. In November 2016 - March 2017 highly pathogenic influenza outbreaks were registered in Russia among wild birds and poultry. No cases of human infection were registered. Analysis of 760 sera from people who had contact with infected or perished birds revealed the presence of antibodies to A(H5N1) virus of clade 2.3.2.1c and A(H5N8) virus of clade 2.3.4.4. The 2016-2017 influenza epidemic season in Russia began in weeks 46-47 of 2016 with predominant circulation of influenza A(H3N2) viruses. Strains isolated from severe influenza cases mainly belonged to 3C.2a.2 and 3C.2a.3 genetic groups. Up to the 8th week of 2017 severe influenza cases were often caused by influenza B viruses which belonged to 1A genetic group with antigenic properties similar to B/Brisbane/60/2008. All influenza A and B virus strains isolated in the 2016-2017 epidemic season were sensitive to oseltamivir and zanamivir.


Assuntos
Anticorpos Antivirais/sangue , Vírus da Influenza A Subtipo H3N2/imunologia , Virus da Influenza A Subtipo H5N1/imunologia , Vírus da Influenza A Subtipo H5N8/imunologia , Influenza Aviária/epidemiologia , Influenza Humana/epidemiologia , Doenças das Aves Domésticas/epidemiologia , Animais , Antivirais/uso terapêutico , Aves , Epidemias , Humanos , Imunidade Coletiva/imunologia , Vírus da Influenza A Subtipo H3N2/efeitos dos fármacos , Vírus da Influenza A Subtipo H3N2/isolamento & purificação , Virus da Influenza A Subtipo H5N1/efeitos dos fármacos , Virus da Influenza A Subtipo H5N1/isolamento & purificação , Vírus da Influenza A Subtipo H5N8/efeitos dos fármacos , Vírus da Influenza A Subtipo H5N8/isolamento & purificação , Vírus da Influenza B/efeitos dos fármacos , Vírus da Influenza B/isolamento & purificação , Influenza Humana/imunologia , Influenza Humana/mortalidade , Influenza Humana/virologia , Oseltamivir/uso terapêutico , Aves Domésticas/virologia , Doenças das Aves Domésticas/virologia , Federação Russa/epidemiologia , Zanamivir/uso terapêutico
12.
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
13.
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
14.
Infect Genet Evol ; 62: 275-278, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29705362

RESUMO

A H5N6 highly pathogenic avian influenza virus (HPAIV) was detected in a black-faced spoonbill (Platalea minor) found dead in Taiwan during December 2017. Genome sequencing and phylogenetic analyses suggest the hemagglutinin gene belongs to H5 clade 2.3.4.4 Group B. All genes except neuraminidase gene shared high levels of nucleotide identity with H5N8 HPAIV identified from Europe during 2016-2017. Genetically similar H5N6 HPAIV was also identified from Japan during November 2017. Enhanced surveillance is required in this region.


Assuntos
Aves/virologia , Genoma Viral , Vírus da Influenza A Subtipo H5N8/isolamento & purificação , Influenza Aviária/virologia , Vírus Reordenados/genética , Animais , Evolução Biológica , Influenza Aviária/epidemiologia , Filogenia , Taiwan
16.
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
17.
Transbound Emerg Dis ; 65(5): 1217-1226, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29536643

RESUMO

Circulation of highly pathogenic avian influenza (HPAI) viruses poses a continuous threat to animal and public health. After the 2005-2006 H5N1 and the 2014-2015 H5N8 epidemics, another H5N8 is currently affecting Europe. Up to August 2017, 1,112 outbreaks in domestic and 955 in wild birds in 30 European countries have been reported, the largest epidemic by a HPAI virus in the continent. Here, the main epidemiological findings are described. While some similarities with previous HPAI virus epidemics were observed, for example in the pattern of emergence, significant differences were also patent, in particular the size and extent of the epidemic. Even though no human infections have been reported to date, the fact that A/H5N8 has affected so far 1,112 domestic holdings, increases the risk of exposure of humans and therefore represents a concern. Understanding the epidemiology of HPAI viruses is essential for the planning future surveillance and control activities.


Assuntos
Doenças Transmissíveis Emergentes/veterinária , Surtos de Doenças/veterinária , Vírus da Influenza A Subtipo H5N8/patogenicidade , Influenza Aviária/epidemiologia , Animais , Animais Selvagens/virologia , Doenças Transmissíveis Emergentes/epidemiologia , Doenças Transmissíveis Emergentes/virologia , Europa (Continente)/epidemiologia , Humanos , Vírus da Influenza A Subtipo H5N8/isolamento & purificação , Influenza Aviária/virologia , Aves Domésticas/virologia , Saúde Pública
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.
Biochem Biophys Res Commun ; 498(4): 758-763, 2018 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-29524417

RESUMO

The H5 subtype of highly pathogenic avian influenza (H5 HPAI) viruses is a threat to both animal and human public health and has the potential to cause a serious future pandemic in humans. Thus, specific and rapid detection of H5 HPAI viruses is required for infection control in humans. To develop a simple and rapid diagnostic system to detect H5 HPAI viruses with high specificity and sensitivity, we attempted to prepare monoclonal antibodies (mAbs) that specifically recognize linear epitopes in hemagglutinin (HA) of H5 subtype viruses. Nine mAb clones were obtained from mice immunized with a synthetic partial peptide of H5 HA molecules conserved among various H5 HPAI viruses. The antigen-capture enzyme-linked immunosorbent assay using the most suitable combination of these mAbs, which bound specifically to lysed H5 HA under an optimized detergent condition, was specific for H5 viruses and could broadly detect H5 viruses in multiple different clades. Taken together, these peptide mAbs, which recognize linear epitopes in a highly conserved region of H5 HA, may be useful for specific and highly sensitive detection of H5 HPAI viruses and can help in the rapid diagnosis of human, avian, and animal H5 virus infections.


Assuntos
Anticorpos Monoclonais/química , Ensaio de Imunoadsorção Enzimática/métodos , Glicoproteínas de Hemaglutininação de Vírus da Influenza/análise , Virus da Influenza A Subtipo H5N1/isolamento & purificação , Vírus da Influenza A Subtipo H5N2/isolamento & purificação , Vírus da Influenza A Subtipo H5N8/isolamento & purificação , Infecções por Orthomyxoviridae/virologia , Animais , Anticorpos Monoclonais/imunologia , Glicoproteínas de Hemaglutininação de Vírus da Influenza/imunologia , Humanos , Virus da Influenza A Subtipo H5N1/imunologia , Vírus da Influenza A Subtipo H5N2/imunologia , Vírus da Influenza A Subtipo H5N8/imunologia , Influenza Humana/diagnóstico , Influenza Humana/imunologia , Influenza Humana/virologia , Camundongos Endogâmicos BALB C , Infecções por Orthomyxoviridae/diagnóstico , Infecções por Orthomyxoviridae/imunologia
20.
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
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