RESUMO
In May 2022, we observed a substantial die-off of wild migratory waterbirds on Maliy Zhemchuzhniy Island in the Caspian Sea, Russia. The deaths were caused by highly pathogenic avian influenza A(H5N1) clade 2.3.4.4.b virus. Continued surveillance of influenza viruses in wild bird populations is needed to predict virus spread over long distances.
Assuntos
Virus da Influenza A Subtipo H5N1 , Vírus da Influenza A , Influenza Aviária , Animais , Virus da Influenza A Subtipo H5N1/genética , Mar Cáspio , Influenza Aviária/epidemiologia , Aves , Federação Russa/epidemiologiaRESUMO
Two variants of highly pathogenic avian influenza A(H5N8) virus were detected in dead poultry in Western Siberia, Russia, during August and September 2020. One variant was represented by viruses of clade 2.3.4.4b and the other by a novel reassortant between clade 2.3.4.4b and Eurasian low pathogenicity avian influenza viruses circulating in wild birds.
Assuntos
Vírus da Influenza A Subtipo H5N8 , Influenza Aviária , Animais , Animais Selvagens , Aves , Surtos de Doenças , Vírus da Influenza A Subtipo H5N8/genética , Influenza Aviária/epidemiologia , Filogenia , Vírus Reordenados/genética , Federação Russa/epidemiologia , Sibéria/epidemiologiaRESUMO
Analyses of HPAI H5 viruses from poultry outbreaks across a wide Eurasian region since July 2020 including the Russian Federation, Republics of Iraq and Kazakhstan, and recent detections in migratory waterfowl in the Netherlands, revealed undetected maintenance of H5N8, likely in galliform poultry since 2017/18 and both H5N5 and H5N1. All viruses belong to A/H5 clade 2.3.4.4b with closely related HA genes. Heterogeneity in Eurasian H5Nx HPAI emerging variants threatens poultry production, food security and veterinary public health.
Assuntos
Surtos de Doenças/veterinária , Vírus da Influenza A/classificação , Vírus da Influenza A/patogenicidade , Influenza Aviária/epidemiologia , Aves Domésticas/virologia , Animais , Virus da Influenza A Subtipo H5N1/classificação , Virus da Influenza A Subtipo H5N1/isolamento & purificação , Virus da Influenza A Subtipo H5N1/patogenicidade , 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/isolamento & purificação , Iraque/epidemiologia , Cazaquistão/epidemiologia , Países Baixos/epidemiologia , Filogenia , Federação Russa/epidemiologia , Sequenciamento Completo do GenomaRESUMO
The emergence of novel avian influenza viruses in migratory birds is of concern because of the potential for virus dissemination during fall migration. We report the identification of novel highly pathogenic avian influenza viruses of subtype H5N8, clade 2.3.4.4, and their reassortment with other avian influenza viruses in waterfowl and shorebirds of Siberia.
Assuntos
Animais Selvagens , Aves/virologia , Vírus da Influenza A Subtipo H5N8/classificação , Vírus da Influenza A Subtipo H5N8/genética , Influenza Aviária/epidemiologia , Influenza Aviária/virologia , Vírus Reordenados , Animais , Surtos de Doenças , Genes Virais , História do Século XXI , Influenza Aviária/história , Filogenia , Vigilância em Saúde Pública , Federação Russa/epidemiologiaRESUMO
An earlier study on commercial chickens and turkeys with a history of respiratory disease established Mycoplasma gallisepticum infection rates on 164 poultry farms of the Russian Federation. Forty-seven (29%) of these poultry farms were M. gallisepticum-positive by polymerase chain reaction but isolation of the mycoplasma was successful only on 10 farms. Five field isolates from different farms were selected for pathogenicity studies in specific pathogen-free chicks. Clinical signs, seroconversion, culture rates, air sac and tracheal lesions and mean tracheal mucosal thickness were all assessed in comparison with the reference strain, S6. Of the five isolates, MG140905 and MG070607 appeared to be slightly more pathogenic than the other three, as indicated by clinical signs, culture-positive rates and lesions, but only isolate MG140905 differed statistically (P < 0.05) from them, thus proving to be the most pathogenic. However, none of the Russian field isolates was as pathogenic as the S6 strain by the parameters measured. Stress or other factors such as concurrent bacterial or viral infections may have served as exacerbating factors for the disease seen in the naturally affected flocks. Sequence analysis of the gapA and mgc2 genes showed that MG140905 clustered with M. gallisepticum R(low) and was more distant from the majority of the Russian isolates.
Assuntos
Galinhas/microbiologia , Infecções por Mycoplasma/veterinária , Mycoplasma gallisepticum/genética , Mycoplasma gallisepticum/patogenicidade , Doenças das Aves Domésticas/microbiologia , Perus/microbiologia , Adesinas Bacterianas/genética , Sacos Aéreos/patologia , Animais , Proteínas de Bactérias/genética , Sequência de Bases , DNA Bacteriano/química , DNA Bacteriano/genética , Dados de Sequência Molecular , Infecções por Mycoplasma/microbiologia , Distribuição Aleatória , Federação Russa , Análise de Sequência de DNA , Organismos Livres de Patógenos Específicos , Traqueia/patologia , VirulênciaRESUMO
In April 2008 an avian influenza outbreak was diagnosed in Primorsky Krai, Russia, during the spring migration of wild birds, and A/Chicken/Primorsky/85/08 H5N1 isolate was recovered. The virus had more than 99% genetic identity with A/Whooper Swan/Hokkaido/1/08 H5N1 and A/Whooper Swan/Hokkaido/2/08 H5N1 viruses that were isolated in April 2008 in Japan. The amino acid sequence of the hemagglutinin cleavage site (PQRERRRKRGLF) and intravenous pathotyping index value (IVPI 2.80) were determined; on this basis the virus was characterized as highly pathogenic. The hemagglutinin gene of the virus was shown to belong to clade 2.3.2 while other genes (PB1, PB2, PA, NP, NA, M, NS) were characteristic of Fujian-like sublineage, recovered in the territory of Russia for the first time.
