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1.
J Vet Sci ; 20(5): e56, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31565899

RESUMO

Korea is located within the East Asian-Australian flyway of wild migratory birds during the fall and winter seasons. Consequently, the likelihood of introduction of numerous subtypes and pathotypes of the Avian influenza (AI) virus to Korea has been thought to be very high. In the current study, we surveyed wild bird feces for the presence of AI virus that had been introduced to Korea between September 2017 and February 2018. To identify and characterize the AI virus, we employed commonly used methods, namely, virus isolation (VI) via egg inoculation, real-time reverse transcription-polymerase chain reaction (rRT-PCR), conventional RT-PCR (cRT-PCR) and a newly developed next generation sequencing (NGS) approach. In this study, 124 out of 11,145 fresh samples of wild migratory birds tested were rRT-PCR positive; only 52.0% of VI positive samples were determined as positive by rRT-PCR from fecal supernatant. Fifty AI virus specimens were isolated from fresh fecal samples and typed. The cRT-PCR subtyping results mostly coincided with the NGS results, although NGS detected the presence of 11 HA genes and four NA genes that were not detected by cRT-PCR. NGS analysis confirmed that 12% of the identified viruses were mixed-subtypes which were not detected by cRT-PCR. Prevention of the occurrence of AI virus requires a workflow for rapid and accurate virus detection and verification. However, conventional methods of detection have some limitations. Therefore, different methods should be combined for optimal surveillance, and further studies are needed in aspect of the introduction and application of new methods such as NGS.


Assuntos
Aves , Monitoramento Epidemiológico/veterinária , Vírus da Influenza A/isolamento & purificação , Influenza Aviária/epidemiologia , Animais , Animais Selvagens , Influenza Aviária/virologia , Vigilância da População/métodos , Prevalência , República da Coreia/epidemiologia
2.
Acta Biochim Pol ; 66(3): 329-336, 2019 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-31531422

RESUMO

The potential emergence of deadly pandemic influenza viruses is unpredictable and most have emerged with no forewarning. The distinct epidemiological and pathological patterns of the Spanish (H1N1), pandemic-2009 (H1N1), and avian influenza (H5N1), known as bird flu, viruses may allow us to develop a 'template' for possible emergence of devastating pandemic strains. Here, we provide a detailed molecular dissection of the structural and nonstructural proteins of this triad of viruses. GenBank data for three representative strains were analyzed to determine the polymorphic amino acids, genetic distances, and isoelectric points, hydrophobicity plot, and protein modeling of various proteins. We propose that the most devastating pandemic strains may have full-length PB1-F2 protein with unique residues, highly cleavable HA, and a basic NS1. Any newly emerging strain should be compared with these three strains, so that resources can be directed appropriately.


Assuntos
Simulação por Computador , Vírus da Influenza A Subtipo H1N1/genética , Virus da Influenza A Subtipo H5N1/genética , Influenza Aviária/virologia , Influenza Humana/virologia , Proteínas Virais/química , Animais , Aves , Transmissão de Doença Infecciosa , Genoma Viral , Humanos , Influenza Pandêmica, 1918-1919 , Vacinas contra Influenza , Influenza Aviária/epidemiologia , Influenza Aviária/prevenção & controle , Influenza Humana/epidemiologia , Influenza Humana/prevenção & controle , Pandemias , Conformação Proteica em alfa-Hélice , Proteínas Virais/genética
3.
BMC Infect Dis ; 19(1): 762, 2019 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-31477028

RESUMO

BACKGROUND: Avian influenza A (H5N6) virus poses a great threat to the human health since it is capable to cross the species barrier and infect humans. Although human infections are believed to largely originate from poultry contaminations, the transmissibility is unclear and only limited information was available on poultry environment contaminations, especially in Fujian Province. METHODS: A total of 4901 environmental samples were collected and tested for Avian Influenza Virus (AIV) from six cities in Fujian Province through the Fujian Influenza Surveillance System from 2013 to 2017. Two patient-related samples were taken from Fujian's first confirmed H5N6 human case and his backyard chicken feces in 2017. Chi-square test or Fisher's exact probability test was used to compare the AIV and the viral subtype positive rates among samples from different Surveillance cities, surveillance sites, sample types, and seasons. Phylogenetic tree analysis and molecular analysis were conducted to track the viral transmission route of the human infection and to map out the evolutions of H5N6 in Fujian. RESULTS: The overall positive rate of the H5 subtype AIVs was 4.24% (208/4903). There were distinctive differences (p < 0.05) in the positive rates in samples from different cities, sample sites, sample types and seasons. The viruses from the patient and his backyard chicken feces shared high homologies (99.9-100%) in all the eight gene segments. Phylogenetic trees also showed that these two H5N6 viruses were closely related to each other, and were classified into the same genetic clade 2.3.4.4 with another six H5N6 isolates from the environmental samples. The patient's H5N6 virus carried genes from H6N6, H5N8 and H5N6 viruses originated from different areas. The R294K or N294S substitution was not detected in the neuraminidase (NA). The S31 N substitution in the matrix2 (M2) gene was detected but only in one strain from the environmental samples. CONCLUSIONS: The H5 subtype of AIVs has started circulating in the poultry environments in Fujian Province. The patient's viral strain originated from the chicken feces in his backyard. Genetic reassortment in H5N6 viruses in Fujian Province was indicated. The H5N6 viruses currently circulating in Fujian Province were still commonly sensitive to Oseltamivir and Zanamivir, but the resistance against Amantadine has emerged.


Assuntos
Vírus da Influenza A/isolamento & purificação , Influenza Aviária/virologia , Influenza Humana/epidemiologia , Influenza Humana/virologia , Infecções por Orthomyxoviridae/virologia , Aves Domésticas/virologia , Animais , Embrião de Galinha , Galinhas/virologia , China/epidemiologia , Patos/virologia , Meio Ambiente , Microbiologia Ambiental , Genes Virais , Abrigo para Animais/normas , Humanos , Vírus da Influenza A/genética , Influenza Aviária/diagnóstico , Influenza Aviária/epidemiologia , Tipagem Molecular , Infecções por Orthomyxoviridae/diagnóstico , Infecções por Orthomyxoviridae/epidemiologia , Infecções por Orthomyxoviridae/transmissão , Filogenia , Doenças das Aves Domésticas/diagnóstico , Doenças das Aves Domésticas/epidemiologia , Doenças das Aves Domésticas/virologia , Fatores de Risco
4.
Vet Microbiol ; 235: 234-242, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31383307

RESUMO

During 2012-2015, six H5N1 avian influenza viruses were isolated from domestic birds and the environment around Qinghai Lake. Phylogenetic analysis of HA genes revealed that A/chicken/Gansu/XG2/2012 (CK/GS/XG2/12) belonged to clade 2.3.2.1a, while A/environment/Qinghai/1/2013 (EN/QH/1/13), A/chicken/Qinghai/QH1/2015 (CK/QH/QH1/15), A/chicken/Qinghai/QH2/2015 (CK/QH/QH2/15), A/chicken/Qinghai/QH3/2015 (CK/QH/QH3/15), and A/goose/Qinghai/QH6/2015 (GS/QH/QH6/15) belonged to clade 2.3.2.1c. Further analysis of the internal genes of the isolates found that the PB2 gene of EN/QH/1/13 had 99.6% nucleotide identity with that of A/tiger/Jiangsu/1/2013 (H5N1), which clustered into an independent branch with PB2 from multiple subtypes. PB2, PB1, and M genes of CK/QH/QH3/15 were from H9N2, suggesting it was a reassortant of H5N1 and H9N2. Animal studies of three selected viruses revealed that CK/GS/XG2/12, EN/QH/1/13, and CK/QH/QH3/15 were highly lethal to chickens, with intravenous pathogenicity indexes (IVPIs) of 2.97, 2.81, and 3.00, respectively, and systemically replicated in chickens. In a mouse study, three selected H5N1 viruses were highly pathogenic to mice and readily replicated in the lungs, nasal turbinates, kidneys, spleens, and brains. Therefore, isolates in this study appear to be novel reassortants that were circulating at the interface of wild and domestic birds around Qinghai Lake and are lethal to chickens and mice. These data suggest that more extensive surveillance should be implemented, and matched vaccines should be chosen for the domestic birds in this area.


Assuntos
Animais Domésticos/virologia , Virus da Influenza A Subtipo H5N1/genética , Influenza Aviária/epidemiologia , Lagos/virologia , Células A549 , Animais , Galinhas/virologia , China/epidemiologia , Cães , Patos/virologia , Evolução Molecular , Feminino , Humanos , Virus da Influenza A Subtipo H5N1/patogenicidade , Vírus da Influenza A Subtipo H9N2/genética , Vírus da Influenza A Subtipo H9N2/patogenicidade , Influenza Aviária/mortalidade , Influenza Aviária/virologia , Células Madin Darby de Rim Canino , Camundongos , Camundongos Endogâmicos BALB C , Filogenia , Vírus Reordenados/genética , Vírus Reordenados/patogenicidade , Replicação Viral
5.
PLoS Comput Biol ; 15(8): e1007189, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31386651

RESUMO

Model-based phylodynamic approaches recently employed generalized linear models (GLMs) to uncover potential predictors of viral spread. Very recently some of these models have allowed both the predictors and their coefficients to be time-dependent. However, these studies mainly focused on predictors that are assumed to be constant through time. Here we inferred the phylodynamics of avian influenza A virus H9N2 isolated in 12 Asian countries and regions under both discrete trait analysis (DTA) and structured coalescent (MASCOT) approaches. Using MASCOT we applied a new time-dependent GLM to uncover the underlying factors behind H9N2 spread. We curated a rich set of time-series predictors including annual international live poultry trade and national poultry production figures. This time-dependent phylodynamic prediction model was compared to commonly employed time-independent alternatives. Additionally the time-dependent MASCOT model allowed for the estimation of viral effective sub-population sizes and their changes through time, and these effective population dynamics within each country were predicted by a GLM. International annual poultry trade is a strongly supported predictor of virus migration rates. There was also strong support for geographic proximity as a predictor of migration rate in all GLMs investigated. In time-dependent MASCOT models, national poultry production was also identified as a predictor of virus genetic diversity through time and this signal was obvious in mainland China. Our application of a recently introduced time-dependent GLM predictors integrated rich time-series data in Bayesian phylodynamic prediction. We demonstrated the contribution of poultry trade and geographic proximity (potentially unheralded wild bird movements) to avian influenza spread in Asia. To gain a better understanding of the drivers of H9N2 spread, we suggest increased surveillance of the H9N2 virus in countries that are currently under-sampled as well as in wild bird populations in the most affected countries.


Assuntos
Vírus da Influenza A Subtipo H9N2 , Influenza Aviária/transmissão , Modelos Biológicos , Migração Animal , Animais , Animais Selvagens/virologia , Ásia/epidemiologia , Teorema de Bayes , Aves/virologia , Comércio , Biologia Computacional , Monitoramento Ambiental , Vírus da Influenza A Subtipo H9N2/classificação , Vírus da Influenza A Subtipo H9N2/genética , Influenza Aviária/epidemiologia , Influenza Aviária/virologia , Modelos Lineares , Filogeografia/estatística & dados numéricos , Dinâmica Populacional , Aves Domésticas/virologia , Análise Espaço-Temporal
6.
Virology ; 534: 36-44, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31176062

RESUMO

Bangladesh has reported repeated outbreaks of highly pathogenic avian influenza (HPAI) A(H5) viruses in poultry since 2007. Because of the large number of live poultry markets (LPM) relative to the population density of poultry throughout the country, these markets can serve as sentinel sites for HPAI A(H5) detection. Through active LPM surveillance during June 2016-June 2017, HPAI A(H5N6) viruses along with 14 other subtypes of influenza A viruses were detected. The HPAI A(H5N6) viruses belonged to clade 2.3.4.4 and were likely introduced into Bangladesh around March 2016. Human infections with influenza clade 2.3.4.4 viruses in Bangladesh have not been identified, but the viruses had several molecular markers associated with potential human infection. Vigilant surveillance at the animal-human interface is essential to identify emerging avian influenza viruses with the potential to threaten public and animal health.


Assuntos
Vírus da Influenza A/isolamento & purificação , Influenza Aviária/virologia , Doenças das Aves Domésticas/virologia , Animais , Bangladesh/epidemiologia , Surtos de Doenças , Patos , Evolução Molecular , Gansos/virologia , Vírus da Influenza A/classificação , Vírus da Influenza A/genética , Influenza Aviária/epidemiologia , Filogenia , Doenças das Aves Domésticas/epidemiologia
7.
Emerg Microbes Infect ; 8(1): 823-826, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31164049

RESUMO

The spread of highly pathogenic avian influenza (HPAI) H5N1 virus is associated with wild fowl migration in East Asian-Australasian (EA) and Central Asian (CA) flyways. However, the spread of H5N1 virus between the two flyways is still unclear. Here, the movements of wild waterfowl were obtained from satellite tracking data covering seven bar-headed geese and three great black-headed gulls breeding in the Qinghai Lake area (along the EA flyway), and 20 whooper swans wintering in the Sanmenxia Reservoir area (at the CA flyway). From the 2688 samples that were screened from wild birds at Qinghai Lake after an outbreak of H5N1 in July 2015, four genomes of H5N1 virus were obtained from bar-headed geese. The results of phylogenetic analysis indicated that these H5N1 viruses belonged to clade 2.3.2.1c and their gene fragments were highly homologous with A/whooper swan/Henan/SMX1/2015 (H5N1) virus (ranging from 99.76% to 100.00%) isolated from a dead whooper swan from the Sanmenxia Reservoir area along the EA flyway in January 2015. Furthermore, the coincidental timing of the H5N1 outbreak with spring migration, together with phylogenetic evidence, provided new evidence of the east-to-west spread of HPAI H5N1 between the EA and CA migratory flyways of China.


Assuntos
Anseriformes/fisiologia , Virus da Influenza A Subtipo H5N1/fisiologia , Influenza Aviária/epidemiologia , Migração Animal , Animais , Animais Selvagens/fisiologia , Animais Selvagens/virologia , Anseriformes/virologia , Ásia/epidemiologia , Austrália/epidemiologia , China/epidemiologia , Virus da Influenza A Subtipo H5N1/classificação , Virus da Influenza A Subtipo H5N1/genética , Virus da Influenza A Subtipo H5N1/isolamento & purificação , Influenza Aviária/transmissão , Influenza Aviária/virologia , Filogenia , Estações do Ano
8.
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
9.
BMC Bioinformatics ; 20(Suppl 8): 288, 2019 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-31182019

RESUMO

BACKGROUND: Avian influenza virus can directly cross species barriers and infect humans with high fatality. As antigen novelty for human host, the public health is being challenged seriously. The pandemic risk of avian influenza viruses should be analyzed and a prediction model should be constructed for virology applications. RESULTS: The 178 signature positions in 11 viral proteins were firstly screened as features by the scores of five amino acid factors and their random forest rankings. The Supporting Vector Machine algorithm achieved well performance. The most important amino acid factor (Factor 5) and the minimal range of signature positions (63 amino acid residues) were also explored. Moreover, human-origin avian influenza viruses with three or four genome segments from human virus had pandemic risk with high probability. CONCLUSION: Using machine learning methods, the present paper scores the amino acid mutations and predicts pandemic risk with well performance. Although long evolution distances between avian and human viruses suggest that avian influenza virus in nature still need time to fix among human host, it should be notable that there are high pandemic risks for H7N9 and H9N2 avian viruses.


Assuntos
Aminoácidos/genética , Aves/virologia , Influenza Aviária/epidemiologia , Influenza Aviária/virologia , Mutação/genética , Pandemias , Algoritmos , Animais , Simulação por Computador , Bases de Dados como Assunto , Genoma Viral , Aprendizado de Máquina , Vírus Reordenados/genética , Fatores de Risco
10.
Microb Pathog ; 135: 103613, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31254602

RESUMO

Avian influenza viruses (AIVs) in wild birds pose a pandemic threat to humans and to the poultry industry. To assess AIV and AIV antibody prevalence in wild birds in China, a systematic review and meta-analysis were conducted. We searched PubMed, Google Scholar, Cochrane Library, Clinical Trial, VIP, CNKI, and WANFANG for published papers related to the prevalence of AIVs and their associated antibodies in wild birds in China from Mar. 10, 2005 to Sept. 20, 2018. Repeat studies, reviews, and other host studies were excluded, as well as those with inconsistent data, incomplete information, or only prevalence data or data from outside of mainland China. In total, data from 28 publications were compiled and analyzed. Based on out meta-analysis, the pooled prevalence of AIVs in wild birds in China was found to be 2.5% (571/23,024), and the pooled prevalence of AIV antibodies was 26.5% (1,210/4,566). The pooled prevalence of AIVs was significantly higher in wild birds from Central China (5.5%, 271/4, 955) compared to all other regions and the pooled prevalence of AIV antibodies was significantly in wild birds from South China (56.8%, 92/162) in comparison to all other regions. The prevalence of both AIVs and AIV antibodies in Anseriformes were higher compared to non-Anseriformes. In addition, the largest number of studies found in this review were on the HA subtypes of AIVs (H5, H7, and H9) and their associated antibodies. In summary, our findings suggest that the prevalence of AIVs and their antibodies in wild birds vary among regions and species of wild bird. Thus, further monitoring of the prevalence of AIVs and their antibodies in wild birds in China is necessary and should be used for guiding powerful and effective regulatory measures that will prevent the spread of AIVs across species.


Assuntos
Animais Selvagens/virologia , Anticorpos/sangue , Aves/virologia , Vírus da Influenza A , Influenza Aviária/epidemiologia , Influenza Aviária/imunologia , Animais , China/epidemiologia , Bases de Dados Factuais , Pandemias , Prevalência
11.
BMC Infect Dis ; 19(1): 458, 2019 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-31117981

RESUMO

BACKGROUND: Since 2008, avian influenza surveillance in poultry-related environments has been conducted annually in China. Samples have been collected from environments including live poultry markets, wild bird habitats, slaughterhouses, and poultry farms. Multiple subtypes of avian influenza virus have been identified based on environmental surveillance, and an H1N8 virus was isolated from the drinking water of a live poultry market. METHODS: Virus isolation was performed by inoculating influenza A-positive specimens into embryonated chicken eggs. Next-generation sequencing was used for whole-genome sequencing. A solid-phase binding assay was performed to test the virus receptor binding specificity. Trypsin dependence plaque formation assays and intravenous pathogenicity index tests were used to evaluate virus pathogenicity in vitro and in vivo, respectively. Different cell lines were chosen for comparison of virus replication capacity. RESULTS: According to the phylogenetic trees, the whole gene segments of the virus named A/Environment/Fujian/85144/2014(H1N8) were of Eurasian lineage. The HA, NA, PB1, and M genes showed the highest homology with those of H1N8 or H1N2 subtype viruses isolated from local domestic ducks, while the PB2, PA, NP and NS genes showed high similarity with the genes of H7N9 viruses detected in 2017 and 2018 in the same province. This virus presented an avian receptor binding preference. The plaque formation assay showed that it was a trypsin-dependent virus. The intravenous pathogenicity index (IVPI) in chickens was 0.02. The growth kinetics of the A/Environment/Fujian/85144/2014(H1N8) virus in different cell lines were similar to those of a human-origin virus, A/Brisbane/59/2007(H1N1), but lower than those of the control avian-origin and swine-origin viruses. CONCLUSIONS: The H1N8 virus was identified in avian influenza-related environments in China for the first time and may have served as a gene carrier involved in the evolution of the H7N9 virus in poultry. This work further emphasizes the importance of avian influenza virus surveillance, especially in live poultry markets (LPMs). Active surveillance of avian influenza in LPMs is a major pillar supporting avian influenza control and response.


Assuntos
Vírus da Influenza A/genética , Vírus da Influenza A/patogenicidade , Influenza Aviária/virologia , Doenças das Aves Domésticas/virologia , Animais , Linhagem Celular , Embrião de Galinha , Galinhas , China , Patos , Humanos , Vírus da Influenza A Subtipo H1N1/genética , Subtipo H7N9 do Vírus da Influenza A/genética , Subtipo H7N9 do Vírus da Influenza A/isolamento & purificação , Vírus da Influenza A/isolamento & purificação , Influenza Aviária/epidemiologia , Filogenia , Aves Domésticas/virologia , Tripsina/genética , Tripsina/metabolismo , Sequenciamento Completo do Genoma
12.
Transbound Emerg Dis ; 66(5): 1958-1970, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31077545

RESUMO

Emperor geese (Anser canagicus) are endemic to coastal areas within Beringia and have previously been found to have antibodies to or to be infected with influenza A viruses (IAVs) in Alaska. In this study, we use virological, serological and tracking data to further elucidate the role of emperor geese in the ecology of IAVs in Beringia during the non-breeding period. Specifically, we assess evidence for: (a) active IAV infection during spring staging, autumn staging and wintering periods; (b) infection with novel Eurasian-origin or interhemispheric reassortant viruses; (c) contemporary movement of geese between East Asia and North America; (d) previous exposure to viruses of 14 haemagglutinin subtypes, including Eurasian lineage highly pathogenic (HP) H5 IAVs; and (e) subtype-specific antibody seroconversion and seroreversion. Emperor geese were found to shed IAVs, including interhemispheric reassortant viruses, throughout the non-breeding period; migrate between Alaska and the Russian Far East prior to and following remigial moult; have antibodies reactive to a diversity of IAVs including, in a few instances, Eurasian lineage HP H5 IAVs; and exhibit relatively broad and stable patterns of population immunity among breeding females. Results of this study suggest that emperor geese may play an important role in the maintenance and dispersal of IAVs within Beringia during the non-breeding period and provide information that may be used to further optimize surveillance activities focused on the early detection of Eurasian-origin IAVs in North America.


Assuntos
Doenças das Aves/epidemiologia , Gansos , Vírus da Influenza A/fisiologia , Influenza Aviária/epidemiologia , Alaska/epidemiologia , Animais , Animais Selvagens , Doenças das Aves/virologia , Feminino , Vírus da Influenza A/classificação , Influenza Aviária/virologia , Prevalência , Federação Russa/epidemiologia , Estações do Ano
13.
Acta Trop ; 196: 93-101, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31063711

RESUMO

The purpose of this case study is to examine how environmental disruption and agricultural practices act synergistically to create a perfect storm for the spread of avian influenza. Actors in this case study include the vast permafrost landscape of the Qinghai-Tibet Plateau; a wild goose that migrates over the Himalayas; the highest altitude railway in the world that traverses the plateau into Tibet; and an avian virus (H5N1). Commencing in 2001, tens of thousands of railway workers travelled to remote regions of the plateau to work on the railway. In order to feed and shelter these workers, the Chinese government established captive-bred goose farms as a source of high protein food. Beginning in 2005 and continuing in subsequent years, Qinghai Lake was the scene for the unprecedented appearance of avian influenza among migratory geese. This was a key moment in the global spread of H5N1 to poultry on three continents. Remote sensing technology suggested an ecological pathway for the transfer of avian viruses among chickens, captive-bred geese, and wild geese. Within a region experiencing rapid climate change, Qinghai Lake is warming even faster than the global average. This may relate to the persistent outbreaks of avian flu strains from Qinghai during the past twelve years. Globally, exponential increases in bird flu outbreaks are not merely a matter of chance mutations in flu viruses but also a result of antecedent social and environmental factors. The Qinghai case study provides real-world examples that bring these factors into sharp focus.


Assuntos
Galinhas/virologia , Gansos/virologia , Virus da Influenza A Subtipo H5N1 , Influenza Aviária/epidemiologia , Animais , Surtos de Doenças/veterinária , Influenza Aviária/virologia , Filogenia , Tibet/epidemiologia
14.
Virology ; 533: 1-11, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31071540

RESUMO

An H5N6 highly pathogenic avian influenza virus (HPAIV) outbreak occurred in poultry in Japan during January 2018, and H5N6 HPAIVs killed several wild birds in 3 prefectures during Winter 2017-2018. Time-measured phylogenetic analyses demonstrated that the Hemagglutinin (HA) and internal genes of these isolates were genetically similar to clade 2.3.4.4.B H5N8 HPAIVs in Europe during Winter 2016-2017, and Neuraminidase (NA) genes of the poultry and wild bird isolates were gained through distinct reassortments with AIVs that were estimated to have circulated possibly in Siberia during Summer 2017 and Summer 2016, respectively. Lethal infectious dose to chickens was similar between the poultry and wild-bird isolates. H5N6 HPAIVs during Winter 2017-2018 in Japan had higher 50% chicken lethal doses and lower transmission efficiency than the H5Nx HPAIVs that caused previous outbreaks in Japan, thus explaining in part why cases during the 2017-2018 outbreak were sporadic.


Assuntos
Animais Selvagens/virologia , Aves/virologia , Vírus da Influenza A/isolamento & purificação , Influenza Aviária/virologia , Doenças das Aves Domésticas/virologia , Adesinas de Escherichia coli/genética , Animais , Galinhas , Vírus da Influenza A/classificação , Vírus da Influenza A/genética , Influenza Aviária/epidemiologia , Influenza Aviária/transmissão , Japão/epidemiologia , Filogenia
15.
PLoS One ; 14(5): e0216984, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31125350

RESUMO

In the re-emergence of Highly Pathogenic Avian Influenza (HPAI), live bird markets have been identified to play a critical role. In this repeated cross-sectional study, we combined surveillance data collected monthly on Jakarta's live bird markets over a five-year period, with risk factors related to the structure and management of live bird markets, the trading and slaughtering of birds at these markets, and environmental and demographic conditions in the areas where the markets were located. Over the study period 36.7% (95% CI: 35.1, 38.3) of samples (N = 1315) tested HPAI H5 virus positive. Using General Estimation Equation approaches to account for repeated observations over time, we explored the association between HPAI H5 virus prevalence and potential risk factors. Markets where only live birds and carcasses were sold, but no slaughtering was conducted at or at the vicinity of the markets, had a significantly reduced chance of being positive for H5 virus (OR = 0.2, 95% CI 0.1-0.5). Also, markets, that used display tables for poultry carcasses made from wood, had reduced odds of being H5 virus positive (OR = 0.7, 95% CI 0.5-1.0), while having at least one duck sample included in the pool of samples collected at the market increased the chance of being H5 virus positive (OR = 5.7, 95% CI 3.6-9.2). Markets where parent stock was traded, were more at risk of being H5 virus positive compared to markets where broilers were traded. Finally, the human population density in the district, the average distance between markets and origins of poultry sold at markets and the total rainfall per month were all positively associated with higher H5 virus prevalence. In summary, our results highlight that a combination of factors related to trading and marketing processes and environmental pressures need to be considered to reduce H5 virus infection risk for customers at urban live bird markets. In particular, the relocation of slaughter areas to well-managed separate locations should be considered.


Assuntos
Virus da Influenza A Subtipo H5N1/patogenicidade , Influenza Aviária/epidemiologia , Doenças das Aves Domésticas/epidemiologia , Animais , Galinhas/virologia , Patos/virologia , Monitoramento Ambiental , Humanos , Indonésia/epidemiologia , Vírus da Influenza A , Influenza Aviária/transmissão , Influenza Aviária/virologia , Aves Domésticas/virologia , Doenças das Aves Domésticas/transmissão , Doenças das Aves Domésticas/virologia , Fatores de Risco
16.
BMC Vet Res ; 15(1): 147, 2019 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-31088548

RESUMO

BACKGROUND: Avian influenza (AI) is an infectious viral disease that affects several species and has zoonotic potential. Due to its associated health and economic repercussions, minimizing AI outbreaks is important. However, most control measures are generic and mostly target pathways important for the conventional poultry farms producing chickens, turkeys, and eggs and may not target other pathways that may be specific to the upland game bird sector. The goal of this study is to provide evidence to support the development of novel strategies for sector-specific AI control by comparing and contrasting practices and potential pathways for spread in upland game bird farms with those for conventional poultry farms in the United States. Farm practices and processes, seasonality of activities, geographic location and inter-farm distance were analyzed across the sectors. All the identified differences were framed and discussed in the context of their associated pathways for virus introduction into the farm and subsequent between-farm spread. RESULTS: Differences stemming from production systems and seasonality, inter-farm distance and farm densities were evident and these could influence both fomite-mediated and local-area spread risks. Upland game bird farms operate under a single, independent owner rather than being contracted with or owned by a company with other farms as is the case with conventional poultry. The seasonal marketing of upland game birds, largely driven by hunting seasons, implies that movements are seasonal and customer-vendor dynamics vary between industry groups. Farm location analysis revealed that, on average, an upland game bird premises was 15.42 km away from the nearest neighboring premises with birds compared to 3.74 km for turkey premises. Compared to turkey premises, the average poultry farm density in a radius of 10 km of an upland game bird premises was less than a half, and turkey premises were 3.8 times (43.5% compared with 11.5%) more likely to fall within a control area during the 2015 Minnesota outbreak. CONCLUSIONS: We conclude that the existing differences in the seasonality of production, isolated geographic location and epidemiological seclusion of farms influence AI spread dynamics and therefore disease control measures should be informed by these and other factors to achieve success.


Assuntos
Criação de Animais Domésticos/métodos , Galliformes , Vírus da Influenza A , Influenza Aviária/epidemiologia , Animais , Surtos de Doenças , Geografia , Influenza Aviária/prevenção & controle , Influenza Aviária/transmissão , Estações do Ano , Estados Unidos
18.
Emerg Microbes Infect ; 8(1): 650-661, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31014196

RESUMO

Since November 2008, we have conducted active avian influenza surveillance in Bangladesh. Clades 2.2.2, 2.3.4.2, and 2.3.2.1a of highly pathogenic avian influenza H5N1 viruses have all been identified in Bangladeshi live poultry markets (LPMs), although, since the end of 2014, H5N1 viruses have been exclusively from clade 2.3.2.1a. In June 2015, a new reassortant H5N1 virus (H5N1-R1) from clade 2.3.2.1a was identified, containing haemagglutinin, neuraminidase, and matrix genes of H5N1 viruses circulating in Bangladesh since 2011, plus five other genes of Eurasian-lineage low pathogenic avian influenza A (LPAI) viruses. Here we report the status of circulating avian influenza A viruses in Bangladeshi LPMs from March 2016 to January 2018. Until April 2017, H5N1 viruses exclusively belonged to H5N1-R1 clade 2.3.2.1a. However, in May 2017, we identified another reassortant H5N1 (H5N1-R2), also of clade 2.3.2.1a, wherein the PA gene segment of H5N1-R1 was replaced by that of another Eurasian-lineage LPAI virus related to A/duck/Bangladesh/30828/2016 (H3N8), detected in Bangladeshi LPM in September 2016. Currently, both reassortant H5N1-R1 and H5N1-R2 co-circulate in Bangladeshi LPMs. Furthermore, some LPAI viruses isolated from LPMs during 2016-2017 were closely related to those from ducks in free-range farms and wild birds in Tanguar haor, a wetland region of Bangladesh where ducks have frequent contact with migratory birds. These data support a hypothesis where Tanguar haor-like ecosystems provide a mechanism for movement of LPAI viruses to LPMs where reassortment with poultry viruses occurs adding to the diversity of viruses at this human-animal interface.


Assuntos
Evolução Molecular , Virus da Influenza A Subtipo H5N1/classificação , Virus da Influenza A Subtipo H5N1/genética , Influenza Aviária/virologia , Aves Domésticas , Vírus Reordenados/classificação , Vírus Reordenados/genética , Animais , Bangladesh/epidemiologia , Variação Genética , Genótipo , Virus da Influenza A Subtipo H5N1/isolamento & purificação , Influenza Aviária/epidemiologia , Epidemiologia Molecular , Vírus Reordenados/isolamento & purificação
19.
Prev Vet Med ; 167: 25-31, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-31027717

RESUMO

The implementation of biosecurity measures among farmers is the first line of defense against highly pathogenic avian influenza (HPAI) on poultry farms. Yet much less is known about the association between HPAI outbreak information sources, farmers' risk perception and their adoption of biosecurity behaviors (BBs). To bridge this gap, a survey (n = 426) was conducted to measure the relationship between these factors among poultry farmers in the Chinese provinces of Jiangsu and Anhui. The data reveal that farmers use multiple information sources to obtain information about HPAI outbreaks. Multivariate regression shows that HPAI outbreak information disseminated through business networks is associated with reported adoption of BBs, while farm size and ease of access to a veterinary clinic are associated with both higher risk perception and increased BBs. Moreover, increased BBs are associated with farmers who maintain stable production and sales contractual relationships with poultry product processing and marketing enterprises. The findings of this research will allow authorities to more effectively disseminate HPAI information to poultry farmers through business networks.


Assuntos
Criação de Animais Domésticos , Controle de Doenças Transmissíveis/métodos , Surtos de Doenças/veterinária , Influenza Aviária/prevenção & controle , Aves Domésticas , Adulto , Animais , China/epidemiologia , Coleta de Dados , Surtos de Doenças/prevenção & controle , Feminino , Humanos , Influenza Aviária/epidemiologia , Masculino , Pessoa de Meia-Idade , Percepção , Fatores de Risco
20.
Artigo em Inglês | MEDLINE | ID: mdl-30961818

RESUMO

This study aimed to investigate the prevalence of influenza A viruses in birds and humans residing in the same localities of Sharkia Province, Egypt and the risk factors' assessment in poultry farms. A total of 100 birds comprised of 50 chickens, 25 ducks and 25 wild egrets were sampled. Swab samples were collected from 65 people (50 poultry farm workers and 15 hospitalized patients). All samples were screened for the presence of influenza A viruses using isolation and molecular assays. Avian influenza viruses were only detected in chicken samples (18%) and molecularly confirmed as subtype H5. The infection rate was higher in broilers (40%) than layers (8.6%). Influenza A (H1) pdm09 virus was detected in a single human case (1.54%). All the isolated AI H5 viruses were clustered into clade (2.2.1.2) and shared a high similarity rate at nucleotides and amino acid levels. In addition, they had a multi-basic amino acid motif (ـــPQGEKRRKKR/GLFـــ) at the H5 gene cleavage site that exhibited point mutations. Chicken breed, movement of workers from one flock to another, lack of utensils' disinfection and the introduction of new birds to the farm were significant risk factors associated with highly pathogenic AI H5 virus infection in poultry farms (p ≤ 0.05). Other factors showed no significant association. The HPAI H5 viruses are still endemic in Egypt with continuous mutation. Co-circulation of these viruses in birds and pdm09 viruses in humans raises alarm for the emergence of reassortant viruses that are capable of potentiating pandemics.


Assuntos
Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Virus da Influenza A Subtipo H5N1/isolamento & purificação , Influenza Aviária/epidemiologia , Influenza Humana/epidemiologia , Doenças das Aves Domésticas/epidemiologia , Sequência de Aminoácidos/genética , Animais , Galinhas/virologia , Patos/virologia , Egito/epidemiologia , Fazendas , Feminino , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Humanos , Vírus da Influenza A Subtipo H1N1/genética , Virus da Influenza A Subtipo H5N1/genética , Influenza Aviária/virologia , Influenza Humana/virologia , Masculino , Aves Domésticas/virologia , Doenças das Aves Domésticas/virologia , Prevalência , Fatores de Risco
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