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. iroychow@umd.edu. 2 VA-MD Regional College of Veterinary Medicine, University of Maryland, College Park, MD 20742, USA. yeddulas@umd.edu. 3 VA-MD Regional College of Veterinary Medicine, University of Maryland, College Park, MD 20742, USA. shinkim@umd.edu.



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, https://doi.org/10.1093/infdis/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, https://doi.org/10.1093/infdis/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: https://doi.org/10.1016/j.chom.2018.08.006



  • 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. florian.krammer@mssm.edu.



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.


Differentiated #human #airway #organoids to assess #infectivity of emerging #influenza virus (Proc Natl Acad Sci USA, abstract)

[Source: Proceedings of the National Academy of Sciences of the United States of America, full page: (LINK). Abstract, edited.]

Differentiated human airway organoids to assess infectivity of emerging influenza virus

Jie Zhou, Cun Li, Norman Sachs, Man Chun Chiu, Bosco Ho-Yin Wong, Hin Chu, Vincent Kwok-Man Poon, Dong Wang, Xiaoyu Zhao, Lei Wen, Wenjun Song, Shuofeng Yuan, Kenneth Kak-Yuen Wong, Jasper Fuk-Woo Chan, Kelvin Kai-Wang To, Honglin Chen, Hans Clevers, and Kwok-Yung Yuen

PNAS June 11, 2018. 201806308; published ahead of print June 11, 2018. DOI: https://doi.org/10.1073/pnas.1806308115

Contributed by Hans Clevers, May 15, 2018 (sent for review April 13, 2018; reviewed by Pei-Jer Chen and Bernard Roizman)



Influenza virus infection represents a major threat to public health worldwide. There is no biologically relevant, reproducible, and readily available in vitro model for predicting the infectivity of influenza viruses in humans. Based on the long-term expanding 3D human airway organoids, we developed proximal differentiation and further established a 2D monolayer culture of airway organoids. The resultant 3D and 2D proximal differentiated airway organoids can morphologically and functionally simulate human airway epithelium and as a proof of concept can discriminate human-infective influenza viruses from poorly human-infective viruses. Thus, the proximal differentiated airway organoids can be utilized to predict the infectivity of influenza viruses and, more broadly, provide a universal platform for studying the biology and pathology of the human airway.



Novel reassortant avian influenza H7N9 virus and pandemic 2009 H1N1 (H1N1pdm) virus cause human infections, while avian H7N2 and swine H1N1 virus mainly infect birds and pigs, respectively. There is no robust in vitro model for assessing the infectivity of emerging viruses in humans. Based on a recently established method, we generated long-term expanding 3D human airway organoids which accommodate four types of airway epithelial cells: ciliated, goblet, club, and basal cells. We report differentiation conditions which increase ciliated cell numbers to a nearly physiological level with synchronously beating cilia readily discernible in every organoid. In addition, the differentiation conditions induce elevated levels of serine proteases, which are essential for productive infection of human influenza viruses and low-pathogenic avian influenza viruses. We also established improved 2D monolayer culture conditions for the differentiated airway organoids. To demonstrate the ability of differentiated airway organoids to identify human-infective virus, 3D and 2D differentiated airway organoids are applied to evaluate two pairs of viruses with known distinct infectivity in humans, H7N9/Ah versus H7N2 and H1N1pdm versus an H1N1 strain isolated from swine (H1N1sw). The human-infective H7N9/Ah virus replicated more robustly than the poorly human-infective H7N2 virus; the highly human-infective H1N1pdm virus replicated to a higher titer than the counterpart H1N1sw. Collectively, we developed differentiated human airway organoids which can morphologically and functionally simulate human airway epithelium. These differentiated airway organoids can be applied for rapid assessment of the infectivity of emerging respiratory viruses to human.

Keywords: Avian Influenza; Swine Influenza; Influenza A; Organoids; H1N1; H1N1pdm09; H7N9; H7N2.