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Journal ArticleDOI

Epidemiology, Evolution, and Pathogenesis of H7N9 Influenza Viruses in Five Epidemic Waves since 2013 in China

TL;DR: The different waves of H7N9 regarding their epidemiology, pathogenesis, evolution, and characteristic features are summarized and compared, and factors behind the recent increase in the number of human cases and sudden outbreaks in chickens are speculated on.
About: This article is published in Trends in Microbiology.The article was published on 2017-09-01. It has received 180 citations till now. The article focuses on the topics: Influenza A virus subtype H5N1.
Citations
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Journal ArticleDOI
01 Jan 2020
TL;DR: In this article, the authors present a risk assessment and management framework tailored to SARS-CoV-2 transmission via wastewater, including new tools for environmental surveillance, ensuring adequate disinfection as a component of overall COVID-19 pandemic containment.
Abstract: The COVID-19 pandemic has severely impacted public health and the worldwide economy Converging evidence from the current pandemic, previous outbreaks and controlled experiments indicates that SARS-CoVs are present in wastewater for several days, leading to potential health risks via waterborne and aerosolized wastewater pathways Conventional wastewater treatment provides only partial removal of SARS-CoVs, thus safe disposal or reuse will depend on the efficacy of final disinfection This underscores the need for a risk assessment and management framework tailored to SARS-CoV-2 transmission via wastewater, including new tools for environmental surveillance, ensuring adequate disinfection as a component of overall COVID-19 pandemic containment Converging evidence indicates that SARS-CoVs are present in wastewater for several days with potential health risks This Review analyses knowledge about such risks as well as the potential spread of SARS-CoVs in waterborne, waterborne–aerosolized and waterborne–foodborne pathways during a pandemic

189 citations

Journal ArticleDOI
13 Sep 2018-Viruses
TL;DR: An introduction on IAVs is provided, highlighting the mechanisms of viral evolution, the host spectrum, and the animal/human interface, and various approaches for the prevention of human IAV infections are provided.
Abstract: Influenza A viruses (IAVs) possess a great zoonotic potential as they are able to infect different avian and mammalian animal hosts, from which they can be transmitted to humans. This is based on the ability of IAV to gradually change their genome by mutation or even reassemble their genome segments during co-infection of the host cell with different IAV strains, resulting in a high genetic diversity. Variants of circulating or newly emerging IAVs continue to trigger global health threats annually for both humans and animals. Here, we provide an introduction on IAVs, highlighting the mechanisms of viral evolution, the host spectrum, and the animal/human interface. Pathogenicity determinants of IAVs in mammals, with special emphasis on newly emerging IAVs with pandemic potential, are discussed. Finally, an overview is provided on various approaches for the prevention of human IAV infections.

154 citations


Cites background from "Epidemiology, Evolution, and Pathog..."

  • ...As indicated, the highest number of human H7N9 infections has been reported during the fifth epidemic wave, with a geographic range expansion within Chinese provinces [128]....

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Journal ArticleDOI
28 Aug 2018-Viruses
TL;DR: Given the global disease burden of an influenza pandemic, continued surveillance and pandemic preparedness efforts against H5 GsGd and Asian lineage H7N9 viruses are warranted.
Abstract: The 1918 H1N1 Spanish Influenza pandemic was the most severe pandemic in modern history. Unlike more recent pandemics, most of the 1918 H1N1 virus' genome was derived directly from an avian influenza virus. Recent avian-origin H5 A/goose/Guangdong/1/1996 (GsGd) and Asian H7N9 viruses have caused several hundred human infections with high mortality rates. While these viruses have not spread beyond infected individuals, if they evolve the ability to transmit efficiently from person-to-person, specifically via the airborne route, they will initiate a pandemic. Therefore, this review examines H5 GsGd and Asian H7N9 viruses that have caused recent zoonotic infections with a focus on viral properties that support airborne transmission. Several GsGd H5 and Asian H7N9 viruses display molecular changes that potentiate transmission and/or exhibit ability for limited transmission between ferrets. However, the hemagglutinin of these viruses is unstable; this likely represents the most significant obstacle to the emergence of a virus capable of efficient airborne transmission. Given the global disease burden of an influenza pandemic, continued surveillance and pandemic preparedness efforts against H5 GsGd and Asian lineage H7N9 viruses are warranted.

111 citations


Cites background from "Epidemiology, Evolution, and Pathog..."

  • ...Sequence analysis of the early isolates and viruses from subsequent epidemic waves found that the majority of isolates carried the HA mutations G186V and Q226L (H3 numbering), which enhance binding to α2,6-SAs [116,118]....

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  • ...Highly pathogenic H7N9 viruses were also isolated from chickens, suggesting the virus originated in these animals [116,117,150,151]....

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Journal ArticleDOI
TL;DR: The genesis of novel influenza A virus strains by reassortment and evolution in wild and domestic bird populations, as well as the role of wild bird migration in their long-range spread are described.
Abstract: In 1918, a strain of influenza A virus caused a human pandemic resulting in the deaths of 50 million people. A century later, with the advent of sequencing technology and corresponding phylogenetic methods, we know much more about the origins, evolution and epidemiology of influenza epidemics. Here we review the history of avian influenza viruses through the lens of their genetic makeup: from their relationship to human pandemic viruses, starting with the 1918 H1N1 strain, through to the highly pathogenic epidemics in birds and zoonoses up to 2018. We describe the genesis of novel influenza A virus strains by reassortment and evolution in wild and domestic bird populations, as well as the role of wild bird migration in their long-range spread. The emergence of highly pathogenic avian influenza viruses, and the zoonotic incursions of avian H5 and H7 viruses into humans over the last couple of decades are also described. The threat of a new avian influenza virus causing a human pandemic is still present today, although control in domestic avian populations can minimize the risk to human health. This article is part of the theme issue 'Modelling infectious disease outbreaks in humans, animals and plants: approaches and important themes'. This issue is linked with the subsequent theme issue 'Modelling infectious disease outbreaks in humans, animals and plants: epidemic forecasting and control'.

108 citations

Journal ArticleDOI
20 Aug 2019-Immunity
TL;DR: In this article, the authors analyzed the response to H7N9 vaccination in naive adults and found that the recall response to conserved epitopes on H7 HA involved a transient expansion of memory B cells with little observed adaptation.

93 citations

References
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Journal ArticleDOI
TL;DR: Wild aquatic bird populations have long been considered the natural reservoir for influenza A viruses with virus transmission from these birds seeding other avian and mammalian hosts, but recent studies in bats have suggested other reservoir species may also exist.

4,155 citations

Journal ArticleDOI
TL;DR: Novel reassortant H7N9 viruses were associated with severe and fatal respiratory disease in three patients, and all three patients died.
Abstract: Background Infection of poultry with influenza A subtype H7 viruses occurs worldwide, but the introduction of this subtype to humans in Asia has not been observed previously. In March 2013, three urban residents of Shanghai or Anhui, China, presented with rapidly progressing lower respiratory tract infections and were found to be infected with a novel reassortant avian-origin influenza A (H7N9) virus. Methods We obtained and analyzed clinical, epidemiologic, and virologic data from these patients. Respiratory specimens were tested for influenza and other respiratory viruses by means of real-time reverse-transcriptase–polymerase-chain-reaction assays, viral culturing, and sequence analyses. Results A novel reassortant avian-origin influenza A (H7N9) virus was isolated from respiratory specimens obtained from all three patients and was identified as H7N9. Sequencing analyses revealed that all the genes from these three viruses were of avian origin, with six internal genes from avian influenza A (H9N2) virus...

2,113 citations

Journal ArticleDOI
TL;DR: The results suggest transmission of the virus from infected chickens to the child without another intermediate mammalian host acting as a "mixing vessel" illustrates the importance of intensive global influenza surveillance.

1,366 citations

Journal ArticleDOI
TL;DR: The writing committee consisted of the following: John H. Beigel, M.D., National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Md, and Jeremy Farrar, D.Phil., Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam.
Abstract: The writing committee consisted of the following: John H. Beigel, M.D., National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Md.; Jeremy Farrar, D.Phil., Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam; Aye Maung Han, M.B., B.S., Department of Child Health, Institute of Medicine, Yangon, Myanmar; Frederick G. Hayden, M.D. (rapporteur), University of Virginia, Charlottesville; Randy Hyer, M.D., World Health Organization, Geneva; Menno D. de Jong, M.D., Ph.D., Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam; Sorasak Lochindarat, M.D., Queen Sirikit National Institute of Child Health, Bangkok, Thailand; Nguyen Thi Kim Tien, M.D., Ph.D., Pasteur Institute, Ho Chi Minh City, Vietnam; Nguyen Tran Hien, M.D., Ph.D., National Institute of Hygiene and Epidemiology, Hanoi; Tran Tinh Hien, M.D., Ph.D., Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam; Angus Nicoll, M.Sc., Health Protection Agency, London; Sok Touch, M.D., Ministry of Health, Phnom Penh, Cambodia; and Kwok-Yung Yuen, M.D., University of Hong Kong, Hong Kong SAR, China. Address reprint requests to Dr. Hayden at the Department of Internal Medicine, P.O. Box 800473, University of Virginia Health Sciences Center, Charlottesville, VA 22908, or at fgh@virginia.edu.

1,224 citations

Journal ArticleDOI
TL;DR: Cross species poultry-to-person transmission of this new reassortant H7N9 virus is associated with severe pneumonia and multiorgan dysfunction in human beings and monitoring of the viral evolution and further study of disease pathogenesis will improve disease management, epidemic control, and pandemic preparedness.

784 citations

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