Emergence of #waterfowl-originated #gene cassettes in HPAI #H7N9 viruses caused severe #human #infection in #Fujian, #China (Influenza Other Respir Viruses, abstract)

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

Influenza Other Respir Viruses. 2019 Jun 11. doi: 10.1111/irv.12657. [Epub ahead of print]

Emergence of waterfowl-originated gene cassettes in HPAI H7N9 viruses caused severe human infection in Fujian, China.

Yang L1, Xie J2,3, Zhang Y1, Zhu W1, Li X1, Wei H1, Li Z1, Zhao L2, Bo H1, Liu J1, Dong J1, Chen T1, Shu Y1,4, Weng Y2,3, Wang D1.

Author information: 1 National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China. 2 Fujian center for disease control and prevention, Fuzhou, China. 3 Fujian provincial key laboratory of zoonosis research, Fuzhou, China. 4 School of Public Health Shenzhen, Sun Yat-sen University, Guangdong, China.




Highly pathogenic avian influenza (HPAI) A(H7N9) virus emerged and caused human infections during the 2016-2017 epidemic wave of influenza A(H7N9) viruses in China. We report a human infection with HPAI H7N9 virus and six environmental isolates in Fujian Province, China.


Environmental surveillance was conducted in live poultry markets and poultry farms in Fujian, China. Clinical and epidemiologic data and samples were collected. Real-time RT-PCRs were conducted for each sample, and H7-positive samples were isolated using embryonated chicken eggs. Full genomes of the isolates were obtained by next-generation sequencing. Phylogenetic analysis and antigenic analysis were conducted.


A 59-year-old man who raised about 1000 ducks was identified as HPAI H7N9 infection. Six HPAI H7 viruses were isolated from environmental samples, including five H7N9 viruses and one H7N6 virus. Phylogenetic results showed the human and environmental viruses are highly genetically diverse and containing significantly different gene constellation from that of other HPAI H7N9 previously reported. The internal genes derived from H7N9/H9N2, H5N6, and the Eurasian wild-bird gene pool, indicating waterfowl-originated genotypes, have emerged in HPAI H7N9/N6 viruses and caused human infection.


The new genotypes raise the concern that these HPAI H7 viruses might transmit back into migratory birds and spread to other countries as the HPAI H5Nx viruses. Considering their capability of causing severe infections in both human and poultry, the HPAI H7 viruses in this study pose a risk to public health and the poultry industry and highlight the importance of sustained surveillance of these viruses.

© 2019 The Authors. Influenza and Other Respiratory Viruses Published by John Wiley & Sons Ltd.

KEYWORDS: H7N9 virus; avian influenza; genetic diversity; infection

PMID: 31187583 DOI: 10.1111/irv.12657

Keywords: Avian Influenza; H5N6; H7N6; H7N9; H9N2; Reassortant Strain; Wild birds; Human; Fujian; China.


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Giuseppe Michieli

I am an Italian blogger, active since 2005 with main focus on emerging infectious diseases such as avian influenza, SARS, antibiotics resistance, and many other global Health issues. Other fields of interest are: climate change, global warming, geological and biological sciences. My activity consists mainly in collection and analysis of news, public services updates, confronting sources and making decision about what are the 'signals' of an impending crisis (an outbreak, for example). When a signal is detected, I follow traces during the entire course of an event. I started in 2005 my blog ''A TIME'S MEMORY'', now with more than 40,000 posts and 3 millions of web interactions. Subsequently I added an Italian Language blog, then discontinued because of very low traffic and interest. I contributed for seven years to a public forum (FluTrackers.com) in the midst of the Ebola epidemic in West Africa in 2014, I left the site to continue alone my data tracking job.