Novel #reassortant #H7N2 originating from the #H7N9 highly pathogenic #avian #influenza viruses in #China, 2019 (J Infect., abstract)

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

J Infect. 2019 Aug 29. pii: S0163-4453(19)30256-7. doi: 10.1016/j.jinf.2019.08.016. [Epub ahead of print]

Novel reassortant H7N2 originating from the H7N9 highly pathogenic avian influenza viruses in China, 2019.

Qiu Y1, Sun R2, Hou G2, Yu X2, Li Y2, Li J2, Zhang Q1, Zou F1, Liu H2, Jiang W3.

Author information: 1 Guangdong Key Laboratory of Animal Conservation and Resource Utilization, Guangdong Public Laboratory of Wild Animal Conservation and Utilization, Guangdong Institute of Applied Biological Resources, Guangzhou, China. 2 China Animal Health and Epidemiology Center, Qingdao, China. 3 China Animal Health and Epidemiology Center, Qingdao, China. Electronic address:



In March 2013, the first human case of zoonotic H7N9 avian influenza virus (AIV) infection was reported in China. This virus has been circulating in domestic poultry in China while mutating to highly pathogenic AIV (HPAIV) since 2017, which caused human infections and poultry outbreaks. In 2019, a novel reassortant H7N2 HPAIV, A/chicken/China/SJZ1/2019(SJZ1), was isolated from H7-Re2-vaccinated layers. We analyzed the genetic, pathogenic, and antigenic characteristics of SJZ1. Analysis of the entire SJZ1 genomic sequence revealed that it comprised at least two different sources; the PB2, PB1, PA, HA (H7), M, and NS segments of SJZ1 were directly derived from H7N9 AIVs, whereas the NA (N2) and NP segments of SJZ1 were derived from H9N2 AIVs. Experimental infection revealed that SJZ1 was highly pathogenic in chickens but not in ducks. SJZ1 was shed from and replicated in chickens and ducks. Hemagglutination-inhibition assay and challenge test indicated that SJZ1 exhibited rapid antigenic drift and distinct antigenicity relative to the H7-Re2 vaccine strain, which provides poor protection for SJZ1. Our study reports the emergence of a new reassortant of H7N2 AIV with novel viral characteristics and warns of the challenge we still face to control the zoonotic H7N9 AIVs and their reassortants.

Copyright © 2019. Published by Elsevier Ltd.

KEYWORDS: Antigenic drift; Chickens; Ducks; H7N2; H7N9; Pathogenicity

PMID: 31473272 DOI: 10.1016/j.jinf.2019.08.016

Keywords: Avian Influenza; H7N9; H7N2; H9N2; Reassortant Strain; Poultry; Vaccines; China.


Will #China’s #H7N9 #Control #Strategy Continue to Be Effective? (Open Forum Infect Dis., abstract)

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

Open Forum Infect Dis. 2019 May 31;6(6):ofz258. doi: 10.1093/ofid/ofz258. eCollection 2019 Jun.

Will China’s H7N9 Control Strategy Continue to Be Effective?

Wang GL1, Gray GC2,3,4, Chen JM5, Ma MJ1.

Author information: 1 State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, P. R. China. 2 Division of Infectious Diseases, School of Medicine, Global Health Institute, Duke University, Durham, North Carolina. 3 Global Health Research Center, Duke-Kunshan University, Kunshan, P. R. China. 4 Program in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore. 5 China Animal Health and Epidemiology Center, Ministry of Agriculture, Qingdao, P. R. China.



Since the first outbreak of avian influenza A(H7N9) virus in China in early 2013, several interventions to control the transmission of H7N9 virus from poultry to humans have been implemented. Temporarily closing live poultry markets reduced the risk of human infection to an extent, but it did not prevent the spread of the H7N9 virus among poultry, and this spread eventually led to more human cases. Nevertheless, the mass vaccination of poultry after September 2017 has been highly effective in preventing the H7N9 virus infection in both poultry and humans. In light of the emergence of highly pathogenic H7N9 and H7N2 viruses in unimmunized ducks, vaccination among poultry, especially for ducks, should be accompanied with continued surveillance of H7N9 variants and other avian influenza A viruses that could signal a heightened pandemic risk.

KEYWORDS: H7N9 viruses; avian influenza viruses; interventions; vaccination

PMID: 31263734 PMCID: PMC6592408 DOI: 10.1093/ofid/ofz258

Keywords: Avian Influenza; H7N9; H7N2; Reassortant Strain; Poultry; China; Vaccines.


#Pathogenicity and #Transmissibility of North #American #H7 Low Pathogenic #Avian #Influenza Viruses in #Chickens and Turkeys (Viruses, abstract)

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

Viruses. 2019 Feb 16;11(2). pii: E163. doi: 10.3390/v11020163.

Pathogenicity and Transmissibility of North American H7 Low Pathogenic Avian Influenza Viruses in Chickens and Turkeys.

Roy Chowdhury I1, Yeddula SGR2, Kim SH3.

Author information: 1 VA-MD Regional College of Veterinary Medicine, University of Maryland, College Park, MD 20742, USA. 2 VA-MD Regional College of Veterinary Medicine, University of Maryland, College Park, MD 20742, USA. 3 VA-MD Regional College of Veterinary Medicine, University of Maryland, College Park, MD 20742, USA.



Low pathogenic avian influenza (LPAI) viruses can silently circulate in poultry and wild aquatic birds and potentially mutate into highly pathogenic avian influenza (HPAI) viruses. In the U.S., recent emergence and spread of H7N8 and H7N9 HPAI viruses not only caused devastating losses to domestic poultry but also underscored the capability of LPAI viruses to mutate into HPAI viruses. Therefore, in this study, we evaluated pathogenicity and transmissibility of H7N8 and H7N9 LPAI viruses (the progenitors of HPAI viruses) in chickens and turkeys. We also included H7N2 isolated from an outbreak of LPAI in commercial chickens. H7 viruses replicated more efficiently in the respiratory tract than in the gastrointestinal tract, suggesting that their replication is restricted to the upper respiratory tract. Specifically, H7N2 replicated most efficiently in two-week-old chickens and turkeys. In contrast, H7N8 replicated least efficiently in those birds. Further, replication of H7N2 and H7N9 was restricted in the upper respiratory tract of four-week-old specific-pathogen-free (SPF) and broiler chickens. Despite their restricted replication, the two viruses efficiently transmitted from infected to naïve birds by direct contact, leading to seroconversion of contacted chickens. Our findings suggest the importance of continuous monitoring and surveillance of LPAI viruses in the fields.

KEYWORDS: H7; chickens; low pathogenic avian influenza virus; replication; transmissibility

PMID: 30781528 DOI: 10.3390/v11020163 Free full text

Keywords: Avian Influenza; H7N2; H7N8; H7N9; Poultry; USA.


The #Cat’s #Meow: Using Novel #Serological Approaches to Identify Cat-to- #Human #Influenza A(#H7N2) Transmission (J Infect Dis., summary)

[Source: Journal of Infectious Diseases, full page: (LINK). Summary, edited.]

The Cat’s Meow: Using Novel Serological Approaches to Identify Cat-to-Human Influenza A(H7N2) Transmission

Seema Jain, Erin L Murray

The Journal of Infectious Diseases, jiy596,

Published: 03 November 2018

(See the major Article by Poirot et al on pages XX-XX)

“What greater gift than the love of a cat?”—Charles Dickens, Great Expectations

Avian influenza viruses have rarely been detected in cats and, until 2016, no cat had ever been documented to have an influenza A(H7N2) virus infection or to transmit the virus to a human. In December 2016, the New York City Department of Health and Mental Hygiene (NYC DOHMH) was alerted about a cat admitted to a Manhattan animal shelter on 12 November 2016 that subsequently died and was confirmed positive for influenza A(H7N2) virus, a low-pathogenic avian influenza virus [1, 2].


Keywords: Avian Influenza; H7N2; Cats; Human; USA; NYC.


Detection of #Avian #Influenza A(#H7N2) Virus #Infection Among #Animal #Shelter #Workers Using a Novel Serological Approach— #NYC, 2016–2017 (J Infect Dis., abstract)

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


Detection of Avian Influenza A(H7N2) Virus Infection Among Animal Shelter Workers Using a Novel Serological Approach—New York City, 2016–2017

Eugenie Poirot, Min Z Levine, Kate Russell, Rebekah J Stewart, Justine M Pompey, Sophia Chiu, Alicia M Fry, Liaini Gross, Fiona P Havers, Zhu-Nan Li, Feng Liu, Aldo Crossa, Christopher T Lee, Vanessa Boshuizen, Jennifer L Rakeman, Sally Slavinski, Scott Harper, L Hannah Gould

The Journal of Infectious Diseases, jiy595,

Published: 05 November 2018




In 2016, an influenza A(H7N2) virus outbreak occurred in cats in New York City’s municipal animal shelters. One human infection was initially detected.


We conducted a serological survey using a novel approach to rule out cross-reactive antibodies to other seasonal influenza viruses to determine whether additional A(H7N2) human infections had occurred and to assess exposure risk.


Of 121 shelter workers, one had serological evidence of A(H7N2) infection, corresponding to a seroprevalence of 0.8% (95% confidence interval, .02%–4.5%). Five persons exhibited low positive titers to A(H7N2) virus, indicating possible infection; however, we could not exclude cross-reactive antibody responses to seasonal influenza viruses. The remaining 115 persons were seronegative. The seropositive person reported multiple direct cat exposures without using personal protective equipment and mild illness with subjective fever, runny nose, and sore throat.


We identified a second case of A(H7N2) infection from this outbreak, providing further evidence of cat-to-human transmission of A(H7N2) virus.

influenza, H7N2, outbreak, zoonotic, serology, human infection

Issue Section: Major Article

Keywords: Avian Influenza; H7N2; Cats; Human; USA; NYC.


Rapid #Evolution of #H7N9 Highly Pathogenic [#Influenza] Viruses that Emerged in #China in 2017 (Cell Host Microbe, abstract)

[Source: Cell Host & Microbe, full page: (LINK). Abstract, edited.]

Rapid Evolution of H7N9 Highly Pathogenic Viruses that Emerged in China in 2017

Jianzhong Shi 2, Guohua Deng 2, Shujie Ma 2, Li Jiang, Chengjun Li, Hualan Chen 3

Published: September 27, 2018 / DOI:



  • In 2017 across China, H7N9 HPAI viruses evolved into different genotypes
  • H7N9 and H7N2 HPAI reassortants are well adapted and lethal in ducks
  • An H5/H7 vaccine induced solid protection against H7 viruses in poultry



H7N9 low pathogenic influenza viruses emerged in China in 2013 and mutated to highly pathogenic strains in 2017, resulting in human infections and disease in chickens. To control spread, a bivalent H5/H7 inactivated vaccine was introduced in poultry in September 2017. To monitor virus evolution and vaccine efficacy, we collected 53,884 poultry samples across China from February 2017 to January 2018. We isolated 252 H7N9 low pathogenic viruses, 69 H7N9 highly pathogenic viruses, and one H7N2 highly pathogenic virus, of which two low pathogenic and 14 highly pathogenic strains were collected after vaccine introduction. Genetic analysis of highly pathogenic strains revealed nine genotypes, one of which is predominant and widespread and contains strains exhibiting high virulence in mice. Additionally, some H7N9 and H7N2 viruses carrying duck virus genes are lethal in ducks. Thus, although vaccination reduced H7N9 infections, the increased virulence and expanded host range to ducks pose new challenges.

Keywords: H7N9 highly pathogenic influenza viruses – evolution – virulence – vaccine – mice – ducks – chickens

Keywords: H7N9; Avian Influenza; H7N2; Poultry; Wild Birds; Human; China; Reassortant Strain.


Cross-reactive mouse #mAbs raised against the #hemagglutinin of A/Shanghai/1/2013 (#H7N9) protect against novel H7 virus isolates in the mouse model (Emerg Microbes Infect., abstract)

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

Emerg Microbes Infect. 2018 Jun 20;7(1):110. doi: 10.1038/s41426-018-0115-0.

Cross-reactive mouse monoclonal antibodies raised against the hemagglutinin of A/Shanghai/1/2013 (H7N9) protect against novel H7 virus isolates in the mouse model.

Stadlbauer D1,2, Amanat F1, Strohmeier S1, Nachbagauer R1, Krammer F3.

Author information: 1 Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY, USA. 2 Department of Biotechnology, University of Natural Resources and Life Sciences, Vienna, Austria. 3 Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY, USA.



Influenza viruses remain a major global public health risk. In addition to seasonal influenza viruses, epizootic influenza A H7 subtype viruses of both the Asian and North American lineage are of concern due to their pandemic potential. In China, the simultaneous occurrence of H7N9 zoonotic episodes and seasonal influenza virus epidemics could potentially lead to novel reassortant viruses with the ability to efficiently spread among humans. Recently, the H7N9 virus has evolved into two new lineages, the Pearl River Delta and the Yangtze River Delta clade. This development has also resulted in viruses with a polybasic cleavage site in the hemagglutinin that are highly pathogenic in avian species and have caused human infections. In addition, an outbreak of a highly pathogenic H7N8 strain was reported in the US state of Indiana in 2016. Furthermore, an H7N2 feline virus strain caused an outbreak in cats in an animal shelter in New York City in 2016, resulting in one human zoonotic event. In this study, mouse monoclonal antibodies previously raised against the hemagglutinin of the A/Shanghai/1/2013 (H7N9) virus were tested for their (cross-) reactivity to these novel H7 viruses. Moreover, the functionality of these antibodies was assessed in vitro in hemagglutination inhibition and microneutralization assays. The therapeutic and prophylactic efficacy of the broadly reactive antibodies against novel H7 viruses was determined in vivo in mouse passive transfer-viral challenge experiments. Our results provide data about the conservation of critical H7 epitopes and could inform the selection of pre-pandemic H7 vaccine strains.

PMID: 29925896 DOI: 10.1038/s41426-018-0115-0

Keywords: Avian Influenza; H7N9; H7N8; H7N2; Reassortant Strain; Monoclonal Antibodies; Animal Models.