Immune escape #adaptive #mutations in the #H7N9 #avian #influenza #hemagglutinin protein increase virus #replication #fitness and decrease #pandemic #potential (J Virol., abstract)

[Source: Journal of Virology, full page: (LINK). Abstract, edited.]

Immune escape adaptive mutations in the H7N9 avian influenza hemagglutinin protein increase virus replication fitness and decrease pandemic potential

Pengxiang Chang, Joshua E. Sealy, Jean-Remy Sadeyen, Sushant Bhat, Deimante Lukosaityte, Yipeng Sun, Munir Iqbal

DOI: 10.1128/JVI.00216-20



H7N9 avian influenza viruses (AIVs) continue to evolve and remain a huge threat to human health and the poultry industry. Previously, serially passaging the H7N9 A/Anhui/1/2013 virus in the presence of homologous ferret antiserum resulted in immune escape viruses containing amino acid substitutions alanine to threonine at residues 125 (A125T), 151 (A151T) and leucine to glutamine at residue 217 (L217Q) in the hemagglutinin (HA) protein. These HA mutations have also been found in the field isolates in 2019. To investigate the potential threat of the serum escape mutant viruses to humans and poultry, the impact of these HA substitutions, either individually or in combination, on receptor binding, pH of fusion, thermal stability and virus replication were investigated. Our results showed the serum escape mutant formed large plaques in Madin-Darby canine kidney (MDCK) cells and grew robustly in vitro and in ovo. They had a lower pH of fusion and increased thermal stability. Of note, the serum escape mutant completely lost the ability to bind to human-like receptor analogues. Further analysis revealed that N-linked glycosylation, as a result of A125T or A151T substitutions in HA, resulted in reduced receptor binding avidity toward both human and avian-like receptor analogues, and the A125T+A151T mutations completely abolished human-like receptor binding. The L217Q mutation enhanced the H7N9 acid and thermal stability while the A151T mutation dramatically decreased H7N9 HA thermal stability. To conclude, H7N9 AIVs that contain A125T+A151T+L217Q mutations in HA protein might pose a reduced pandemic risk but remain a heightened threat for poultry.



Avian influenza H7N9 viruses have been causing disease outbreaks in poultry and humans. We previously determined that propagation of H7N9 virus in the virus-specific antiserum give rise to mutant viruses carrying mutations A125T+A151T+L217Q in their hemagglutinin protein, enabling the virus to overcome vaccine-induced immunity. As predicted, these immune escape mutations were also observed in the field viruses that likely emerged in the immunised or naturally exposed birds. This study demonstrates that the immune escape mutants also (i) gained greater replication ability in cultured cells and in chick embryo as well as (ii) increased acid and thermal stability, but (iii) lost preferences for binding to human-type receptor while maintaining binding for the avian-like receptor. Therefore, they potentially pose reduced pandemic risk. However, the emergent virus variants containing indicated mutations remain a significant risk to the poultry due to antigenic drift and improved fitness for poultry.

Copyright © 2020 Chang et al. This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International license.

Keywords: Avian Influenza; H7N9; Poultry; Evolution.


Full-length #genome #sequences of the first #H9N2 #avian #influenza viruses isolated in the Northeast of #Algeria (Virol J., abstract)

[Source: US National Library of Medicine, full page: (LINK). Abstract, edited.]

Virol J. 2020 Jul 17;17(1):108. doi: 10.1186/s12985-020-01377-z.

Full-length genome sequences of the first H9N2 avian influenza viruses isolated in the Northeast of Algeria

Abdelheq Barberis 1 2, Amine Boudaoud 3, Angelina Gorrill 4, Josianne  Loupias 4, Abdeljelil Ghram 5, Jihene Lachheb 5, Nadir Alloui 3, Mariette F Ducatez 6

Affiliations: 1 Centre de Recherche en Biotechnologie, Nouvelle Ville Ali Mendjeli, El Khroub, Algeria. 2 LESPA, Département vétérinaire, ISVSA, Université de Batna, Batna, Algeria. 3 LESPA, Département vétérinaire, ISVSA, Université de Batna, Batna, Algeria. 4 IHAP, Université de Toulouse, INRAE, ENVT, 23 Chemin des Capelles, 31076, Toulouse cedex, France. 5 Laboratoire d’Epidémiologie et de Microbiologie Vétérinaire, Institut Pasteur de Tunis, Université Tunis El Manar, Tunis, Tunisia. 6 IHAP, Université de Toulouse, INRAE, ENVT, 23 Chemin des Capelles, 31076, Toulouse cedex, France.

PMID: 32680533 DOI: 10.1186/s12985-020-01377-z




H9N2 avian influenza viruses (AIV) has a worldwide geographic distribution and affects poultry of different types of production. H9N2 AIV was first reported in the Northeast of Algeria in April 2017, following an outbreak associated with high mortality, in broiler flocks. In the present study, we report full-length genome sequences of AIV H9N2, and the detailed phylogeny and molecular genetic analyses.


Ten AIV H9N2 strains, collected in broiler flocks, were amplified in 9-day-old embryonated specific pathogen free (SPF) chicken eggs. Their full-length genomes were successfully sequenced and phylogenetic and molecular characterizations were conducted.


Phylogenetic analysis showed that the isolates were monophyletic, grouped within the G-1 lineage and were very close to Moroccan and Algerian strains identified in 2016 and 2017, respectively. The low pathogenicity of the strains was confirmed by the sequence motif (335RSSR/GLF341) at the hemagglutinin (HA) cleavage site. An exclusive substitution (T197A) that had not been previously reported for H9N2 viruses; but, conserved in some pandemic H1N1 viruses, was observed. When compared to the G1-like H9N2 prototype, the studied strains showed one less glycosylation site in HA, but 2-3 additional ones in the stalk of the neuraminidase (NA). The HA protein harbored the substitution 234 L, suggesting binding preference to human-like receptors. The NA protein harbored S372A and R403W substitutions, previously detected in H9N2 from Asia and the Middle East, and especially in H2N2 and H3N2 strains that caused human pandemics. Different molecular markers associated with virulence and mammalian infections have been detected in the viral internal proteins. The matrix M2 protein possessed the S31N substitution associated with drug resistance. The non-structural 1 (NS1) protein showed the “GSEV” PDZ ligand (PL) C-terminal motif and no 80-84 deletion.


Characterized Algerian AIV isolates showed mutations that suggest increased zoonotic potential. Additional studies in animal models are required to investigate the pathogenicity of these H9N2 AIV strains. Monitoring their evolution in both migratory and domestic birds is crucial to prevent transmission to humans. Implementation of adequate biosecurity measures that limit the introduction and the propagation of AIV H9N2 in Algerian poultry farm is crucial.

Keywords: Algeria; Avian influenza H9N2; Full-length genome sequencing; Molecular characterization; Phylogenetic analysis.

Keywords: H9N2; Avian Influenza; Poultry; Algeria.


#SARS-CoV-2 in fruit #bats, #ferrets, #pigs, and #chickens: an experimental #transmission study (Lancet Microbe, abstract)

[Source: Lancet Microbe, full page: (LINK). Abstract, edited.]

SARS-CoV-2 in fruit bats, ferrets, pigs, and chickens: an experimental transmission study

Kore Schlottau, PhD †, Melanie Rissmann, DVM †, Annika Graaf, DVM †, Jacob Schön, PhD †, Julia Sehl, DVM, Claudia Wylezich, PhD, Dirk Höper, PhD, Prof Thomas C Mettenleiter, PhD, Anne Balkema-Buschmann, DVM †, Prof Timm Harder, DVM †, Christian Grund, DVM †, Donata Hoffmann, DVM †, Angele Breithaupt, DVM †, Prof Martin Beer, DVM

Open Access | Published: July 07, 2020 | DOI:




In December, 2019, a novel zoonotic severe acute respiratory syndrome-related coronavirus emerged in China. The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) became pandemic within weeks and the number of human infections and severe cases is increasing. We aimed to investigate the susceptibilty of potential animal hosts and the risk of anthropozoonotic spill-over infections.


We intranasally inoculated nine fruit bats (Rousettus aegyptiacus), ferrets (Mustela putorius), pigs (Sus scrofa domesticus), and 17 chickens (Gallus gallus domesticus) with 105 TCID50 of a SARS-CoV-2 isolate per animal. Direct contact animals (n=3) were included 24 h after inoculation to test viral transmission. Animals were monitored for clinical signs and for virus shedding by nucleic acid extraction from nasal washes and rectal swabs (ferrets), oral swabs and pooled faeces samples (fruit bats), nasal and rectal swabs (pigs), or oropharyngeal and cloacal swabs (chickens) on days 2, 4, 8, 12, 16, and 21 after infection by quantitative RT-PCR (RT-qPCR). On days 4, 8, and 12, two inoculated animals (or three in the case of chickens) of each species were euthanised, and all remaining animals, including the contacts, were euthanised at day 21. All animals were subjected to autopsy and various tissues were collected for virus detection by RT-qPCR, histopathology immunohistochemistry, and in situ hybridisation. Presence of SARS-CoV-2 reactive antibodies was tested by indirect immunofluorescence assay and virus neutralisation test in samples collected before inoculation and at autopsy.


Pigs and chickens were not susceptible to SARS-CoV-2. All swabs, organ samples, and contact animals were negative for viral RNA, and none of the pigs or chickens seroconverted. Seven (78%) of nine fruit bats had a transient infection, with virus detectable by RT-qPCR, immunohistochemistry, and in situ hybridisation in the nasal cavity, associated with rhinitis. Viral RNA was also identified in the trachea, lung, and lung-associated lymphatic tissue in two animals euthanised at day 4. One of three contact bats became infected. More efficient virus replication but no clinical signs were observed in ferrets, with transmission to all three direct contact animals. Mild rhinitis was associated with viral antigen detection in the respiratory and olfactory epithelium. Prominent viral RNA loads of 0–104 viral genome copies per mL were detected in the upper respiratory tract of fruit bats and ferrets, and both species developed SARS-CoV-2-reactive antibodies reaching neutralising titres of up to 1/1024 after 21 days.


Pigs and chickens could not be infected intranasally by SARS-CoV-2, whereas fruit bats showed characteristics of a reservoir host. Virus replication in ferrets resembled a subclinical human infection with efficient spread. Ferrets might serve as a useful model for further studies—eg, testing vaccines or antivirals.


German Federal Ministry of Food and Agriculture.

Keywords: SARS-CoV-2; COVID-19; Pigs; Poultry; Bats; Ferrets; Animal models.


#Atypical #Pathogenicity of #Avian #Influenza (#H3N1) Virus Involved in #Outbreak, #Belgium, 2019 (Emerg Infect Dis., abstract)

[Source: US Centers for Disease Control and Prevention (CDC), Emerging Infectious Diseases Journal, full page: (LINK). Abstract, edited.]

Volume 26, Number 8—August 2020 | Dispatch

Atypical Pathogenicity of Avian Influenza (H3N1) Virus Involved in Outbreak, Belgium, 2019

Mieke Steensels  , Philippe Gelaude, Steven Van Borm, Thierry Van Den Berg, Mickaël Cargnel, Virginie Roupie, Fabienne Rauw, and Bénédicte Lambrecht

Author affiliations: Sciensano, Brussels, Belgium (M. Steensels, S. Van Borm, T. Van Den Berg, M. Cargnel, V. Roupie, F. Rauw, B. Lambrecht); Animal Health Vlaanderen, Torhout, Belgium (P. Gelaude)



In 2019, an outbreak of avian influenza (H3N1) virus infection occurred among commercial poultry in Belgium. Full-genome phylogenetic analysis indicated a wild bird origin rather than recent circulation among poultry. Although classified as a nonnotifiable avian influenza virus, it was associated with reproductive tropism and substantial mortality in the field.

Keywords: Avian Influenza; H3N1; Reassortant strain; Poultry; Netherlands.


Genetically and antigenically #divergent #influenza A(#H9N2) viruses exhibit differential #replication and #transmission phenotypes in #mammalian models (J Virol., abstract)

[Source: Journal of Virology, full page: (LINK). Abstract, edited.]

Genetically and antigenically divergent influenza A(H9N2) viruses exhibit differential replication and transmission phenotypes in mammalian models

Jessica A Belser, Xiangjie Sun, Nicole Brock, Claudia Pappas, Joanna A Pulit-Penaloza, Hui Zeng, Yunho Jang, Joyce Jones, Paul J Carney, Jessie Chang, Nguyen Van Long, Nguyen Thi Diep, Sharmi Thor, Han Di, Genyan Yang, Peter W Cook, Hannah M Creager, Dayan Wang, Jeffrey McFarland, Pham Van Dong, David E. Wentworth, Terrence M Tumpey, John R Barnes, James Stevens, C. Todd Davis, Taronna R Maines

DOI: 10.1128/JVI.00451-20



Low pathogenicity avian influenza A(H9N2) viruses, enzootic in poultry populations in Asia, are associated with fewer confirmed human infections but higher rates of seropositivity compared to A(H5) or A(H7) subtype viruses. Co-circulation of A(H5) and A(H7) viruses leads to the generation of reassortant viruses bearing A(H9N2) internal genes with markers of mammalian adaptation, warranting continued surveillance in both avian and human populations. Here, we describe active surveillance efforts in live poultry markets in Vietnam in 2018 and compare representative viruses to G1 and Y280 lineage viruses that have infected humans. Receptor binding properties, pH thresholds for HA activation, in vitro replication in human respiratory tract cells, and in vivo mammalian pathogenicity and transmissibility were investigated. While A(H9N2) viruses from both poultry and humans exhibited features associated with mammalian adaptation, one human isolate from 2018, A/Anhui-Lujiang/39/2018, exhibited increased capacity for replication and transmission, demonstrating the pandemic potential of A(H9N2) viruses.



A(H9N2) influenza viruses are widespread in poultry in many parts of the world, and for over twenty years, have sporadically jumped species barriers to cause human infection. As these viruses continue to diversify genetically and antigenically, it is critical to closely monitor viruses responsible for human infections, to ascertain if A(H9N2) viruses are acquiring properties that make them better suited to infect and spread among humans. In this study, we describe an active poultry surveillance system established in Vietnam to identify the scope of influenza viruses present in live bird markets and the threat they pose to human health. Assessment of a recent A(H9N2) virus isolated from an individual in China in 2018 is also reported and was found to exhibit properties of adaptation to humans and, importantly, show similarities to strains isolated from the live bird markets of Vietnam.

Copyright © 2020 American Society for Microbiology. All Rights Reserved.

Keywords: Avian Influenza; H9N2; Human; Poultry; China; Vietnam.


#Geographical #Variation in the #Risk of #H7N9 #Human #Infections in #China: Implications for Risk-Based #Surveillance (Sci Rep., abstract)

[Source: US National Library of Medicine, full page: (LINK). Abstract, edited.]

Sci Rep. 2020 Jun 25;10(1):10372. doi: 10.1038/s41598-020-66359-1.

Geographical Variation in the Risk of H7N9 Human Infections in China: Implications for Risk-Based Surveillance

Xiaoyan Zhou 1, Lu Gao 2, Youming Wang 2, Yin Li 2 3, Yi Zhang 2, Chaojian Shen 2, Ailing Liu 2, Qi Yu 4, Wenyi Zhang 5, Alexander Pekin 6, Fusheng Guo 7, Carl Smith 8, Archie C A Clements 9 10, John Edwards 6 2 3, Baoxu Huang 11, Ricardo J Soares Magalhães 6 12

Affiliations collapse: 1 School of Veterinary Science, The University of Queensland, Brisbane, Australia. 2 China Animal Health and Epidemiology Centre, Ministry of Agriculture and Rural Affairs, Qingdao, PR China. 3 School of Veterinary and Biomedical Sciences, Murdoch University, Perth, Australia. 4 Beijing Center for Animal Disease Prevention and Control, Beijing, PR China. 5 Institute of Disease Control and Prevention, Academy of Military Medical Science, Beijing, PR China.  6 School of Veterinary Science, The University of Queensland, Brisbane, Australia. 7 Food and Agriculture Organization of the United Nations (FAO), Bangkok, Thailand. 8 School of Business, The University of Queensland, Brisbane, Australia. 9 Faculty of Health Sciences, Curtin University, Perth, Australia. 10 Telethon Kids Institute, Perth, Australia. 11 China Animal Health and Epidemiology Centre, Ministry of Agriculture and Rural Affairs, Qingdao, PR China. 12 Child Health Research Centre, The University of Queensland, Brisbane, Australia.

PMID: 32587266 DOI: 10.1038/s41598-020-66359-1



The influenza A (H7N9) subtype remains a public health problem in China affecting individuals in contact with live poultry, particularly at live bird markets. Despite enhanced surveillance and biosecurity at LBMs H7N9 viruses are now more widespread in China. This study aims to quantify the temporal relationship between poultry surveillance results and the onset of human H7N9 infections during 2013-2017 and to estimate risk factors associated with geographical risk of H7N9 human infections in counties in Southeast China. Our results suggest that poultry surveillance data can potentially be used as early warning indicators for human H7N9 notifications. Furthermore, we found that human H7N9 incidence at county-level was significantly associated with the presence of wholesale LBMs, the density of retail LBMs, the presence of poultry virological positives, poultry movements from high-risk areas, as well as chicken population density and human population density. The results of this study can influence the current AI H7N9 control program by supporting the integration of poultry surveillance data with human H7N9 notifications as an early warning of the timing and areas at risk for human infection. The findings also highlight areas in China where monitoring of poultry movement and poultry infections could be prioritized.

Keywords: Avian Influenza; H7N9; Human; Poultry; China.


#Biosecurity #Risk #Factors for Highly Pathogenic #Avian #Influenza (#H5N8) Virus Infection in #Duck #Farms, #France (Transbound Emerg Dis., abstract)

[Source: US National Library of Medicine, full page: (LINK). Abstract, edited.]

Transbound Emerg Dis. 2020 Jun 11. doi: 10.1111/tbed.13672. Online ahead of print.

Biosecurity Risk Factors for Highly Pathogenic Avian Influenza (H5N8) Virus Infection in Duck Farms, France

C Guinat 1, A Comin 2, G Kratzer 3, B Durand 4, L Delesalle 1, M Delpont 1, J L Guérin 1, M C Paul 1

Affiliations: 1 IHAP, Université de Toulouse, INRA, ENVT, Toulouse, France. 2 Department of Disease Control and Epidemiology, National Veterinary Institute, Uppsala, Sweden. 3 Department of Mathematics, University of Zurich, Zurich, Switzerland. 4 Agence Nationale de Sécurité Sanitaire de l’Alimentation, Maisons-Alfort, France.

PMID: 32526101 DOI: 10.1111/tbed.13672



Highly Pathogenic Avian Influenza (HPAI) subtype H5N8 outbreaks occurred in poultry farms in France in 2016-17, resulting in significant economic losses and disruption to the poultry industry. Current evidence on associations between actual on-farm biosecurity risk factors and H5N8 occurrence is limited. Therefore, a retrospective matched case-control study was undertaken to investigate the inter-relationships between on-farm biosecurity practices and H5N8 infection status to provide new insights regarding promising targets for intervention. Data were collected on 133 case and 133 control duck farms (i.e. the most affected species) located in one area of the country that was mostly affected by the disease. Data were analysed using Additive Bayesian Networks which offer a rich modelling framework by graphically illustrating the dependencies between variables. Factors indirectly and directly positively associated with farm infection were inadequate management of vehicle movements (odds ratio [OR] 9.3, 95% credible interval [CI] 4.0-22.8) and inadequate delimitation of farm and units (OR 3.0, 95% CI 1.6-5.8), respectively. Inadequate disposal of dead birds was instead negatively associated to the outcome (OR 0.1, 95% CI 0.0-0.3). The findings highlight that reinforcing farm access control systems and reducing the number of visitors are key biosecurity measures to control farm vulnerability to H5N8 infection and could help setting priorities in biosecurity practices to prevent outbreaks re-occurrence.

Keywords: additive Bayesian networks; biosecurity risk factors; disease control; graphical modeling; highly pathogenic avian influenza.

This article is protected by copyright. All rights reserved.

Keywords: Avian Influenza; H5N8; Poultry; France.


Regional #Transmission and #Reassortment of Highly Pathogenic #Avian #Influenza (HPAI) Viruses in #Bulgarian #Poultry 2017/18 (Viruses, abstract)

[Source: US National Library of Medicine, full page: (LINK). Abstract, edited.]

Viruses. 2020 Jun 1;12(6):E605. doi: 10.3390/v12060605.

Regional Transmission and Reassortment of Highly Pathogenic Avian Influenza (HPAI) Viruses in Bulgarian Poultry 2017/18

Divya Venkatesh 1, Adam Brouwer 2, Gabriela Goujgoulova 3, Richard Ellis 4, James Seekings 2 5, Ian H Brown 2, Nicola S Lewis 1 2

Affiliations: 1 Department of Pathobiology and Population Sciences, Royal Veterinary College, Hatfield, Hertfordshire AL9 7TA, UK. 2 OIE/FAO/ International Reference Laboratory for avian influenza, swine influenza and Newcastle Disease, Animal and Plant Health Agency (APHA), Weybridge, Addlestone, Surrey KT15 3NB, UK. 3 National Diagnostic Research Veterinary Medical Institute, 1231 Sofia, Bulgaria. 4 Surveillance and Laboratory Services Department, Animal and Plant Health Agency (APHA), Weybridge, Addlestone, Surrey KT15 3NB, UK. 5 Virology Department, Animal and Plant Health Agency (APHA), Weybridge, Addlestone, Surrey KT15 3NB, UK.

PMID: 32492965 DOI: 10.3390/v12060605



Between 2017 and 2018, several farms across Bulgaria reported outbreaks of H5 highly-pathogenic avian influenza (HPAI) viruses. In this study we used genomic and traditional epidemiological analyses to trace the origin and subsequent spread of these outbreaks within Bulgaria. Both methods indicate two separate incursions, one restricted to the northeastern region of Dobrich, and another largely restricted to Central and Eastern Bulgaria including places such as Plovdiv, Sliven and Stara Zagora, as well as one virus from the Western region of Vidin. Both outbreaks likely originate from different European virus ancestors circulating in 2017. The viruses were likely introduced by wild birds or poultry trade links in 2017 and have continued to circulate, but due to lack of contemporaneous sampling and sequences from wild bird viruses in Bulgaria, the precise route and timing of introduction cannot be determined. Analysis of whole genomes indicates a complete lack of reassortment in all segments but the matrix protein gene (MP), which presents as multiple smaller clusters associated with different European viruses. Ancestral reconstruction of host states of the hemagglutinin (HA) gene of viruses involved in the outbreaks suggests that transmission is driven by domestic ducks into galliform poultry. Thus, according to present evidence, we suggest the surveillance of domestic ducks as they are an epidemiologically relevant species for subclinical infection. Monitoring the spread due to movement between farms within regions and links to poultry production systems in European countries can help to predict and prevent future outbreaks. The lineage which caused the largest recorded poultry epidemic in Europe continues to circulate, and the risk of further transmission by wild birds during migration remains.

Keywords: Avian Influenza; H5; Reassortant strain; Poultry; Wild Birds; Bulgaria.


#Epidemiological Characteristics of a Case Infected With #Avian #Influenza A (#H5N6) Virus Associated With #Exposure to #Aerosol (Zhonghua Liu Xing Bing Xue Za Zhi, abstract)

[Source: US National Library of Medicine, full page: (LINK). Abstract, edited.]

Zhonghua Liu Xing Bing Xue Za Zhi. 2020 Mar 10;41(3):358-362. doi: 10.3760/cma.j.issn.0254-6450.2020.03.015.

[Epidemiological Characteristics of a Case Infected With Avian Influenza A (H5N6) Virus Associated With Exposure to Aerosol]

[Article in Chinese]

Y H Liu 1, J Y Lu 1, W H Liu 1, Y Ma 1, L Cao 1, K B Li 1, T G Li 1, Z B Zhang 1, Z C Yang 1

Affiliation: 1 Guangzhou Municipal Center for Disease Control and Prevention, Guangzhou 510440, China.

PMID: 32294835 DOI: 10.3760/cma.j.issn.0254-6450.2020.03.015


Abstract  in English , Chinese


To investigate the epidemiological and clinical characteristics of a case infected with avian influenza A (H5N6) virus associated with exposure to aerosol and provide evidence for the prevention and control of human infection with avian influenza virus.


Epidemiological investigation was conducted to identify the history of exposure, infection route, and disease progression. Real-time fluorescent quantitative RT-PCR was used to test the samples collected from the case, close contacts, environment and poultry market.


The case had no history of exposure to live poultry and poultry market. But before the onset the case had a history of exposure to the live poultry placed in a car with doors and windows closed. The samples collected from the case’s lower respiratory tract and the remaining frozen chicken meat were all influenza A (H5N6) virus positive.


The source of infection was the live poultry, and the infection route might be the exposure to aerosol in a car with doors and windows closed, where the poultry were temporarily stored. It is necessary to promote centralized poultry slaughtering, cold chain distribution and fresh poultry sale, as well as strengthen health education and establish the concept of consuming fresh poultry.

Keywords: Aerosol; Epidemiological investigation; Influenza A (H5N6).

Keywords: Avian Influenza; H5N6; Human; Poultry; China.


Detection of Low Pathogenic #Avian #Influenza Virus Subtype #H10N7 in #Poultry and #Environmental #Water Samples During a Clinical #Outbreak in Commercial Free-Range #Layers, #Netherlands 2017 (Front Vet Sci., abstract)

[Source: US National Library of Medicine, full page: (LINK). Abstract, edited.]

Front Vet Sci. 2020 May 5;7:237. doi: 10.3389/fvets.2020.00237. eCollection 2020.

Detection of Low Pathogenic Avian Influenza Virus Subtype H10N7 in Poultry and Environmental Water Samples During a Clinical Outbreak in Commercial Free-Range Layers, Netherlands 2017

Evelien A Germeraad 1, Armin R W Elbers 2, Naomi D de Bruijn 3, Rene Heutink 1, Wendy van Voorst 1 3, Renate Hakze-van der Honing 1, Saskia A Bergervoet 1, Marc Y Engelsma 1, Wim H M van der Poel 1, Nancy Beerens 1

Affiliations: 1 Wageningen Bioveterinary Research, Department of Virology, Lelystad, Netherlands. 2 Wageningen Bioveterinary Research, Department of Bacteriology and Epidemiology, Lelystad, Netherlands. 3 Poultry Department, GD-Animal Health, Deventer, Netherlands.

PMID: 32478107 PMCID: PMC7232570 DOI: 10.3389/fvets.2020.00237 Free PMC article



Wild birds are the natural reservoir of the avian influenza virus (AIV) and may transmit AIV to poultry via direct contact or indirectly through the environment. In the Netherlands, a clinically suspected free-range layer flock was reported to the veterinary authorities by the farmer. Increased mortality, a decreased feed intake, and a drop in egg production were observed. Subsequently, an infection with low pathogenic avian influenza virus was detected. This study describes the diagnostic procedures used for detection and subtyping of the virus. In addition to routine diagnostics, the potential of two different environmental diagnostic methods was investigated for detecting AIV in surface water. AIV was first detected using rRT-PCR and isolated from tracheal and cloacal swabs collected from the hens. The virus was subtyped as H10N7. Antibodies against the virus were detected in 28 of the 31 sera tested. An intravenous pathogenicity index (IVPI) experiment was performed, but no clinical signs (IVPI = 0) were observed. Post-mortem examination and histology confirmed the AIV infection. Multiple water samples were collected longitudinally from the free-range area and waterway near the farm. Both environmental diagnostic methods allowed the detection of the H10N7 virus, demonstrating the potential of these methods in detection of AIV. The described methods could be a useful additional procedure for AIV surveillance in water-rich areas with large concentrations of wild birds or in areas around poultry farms. In addition, these methods could be used as a tool to test if the environment or free-range area is virus-free again, at the end of an AIV epidemic.

Keywords: LPAIV; environmental sampling; outbreak; poultry; water.

Copyright © 2020 Germeraad, Elbers, de Bruijn, Heutink, van Voorst, Hakze-van der Honing, Bergervoet, Engelsma, van der Poel and Beerens.

Keywords: Avian Influenza; H10N7; Poultry; Wild Birds; Netherlands.