mBio. H7N9 Avian Influenza A Virus and the Perpetual Challenge of Potential Human Pandemicity

[Giuseppe]

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


H7N9 Avian Influenza A Virus and the Perpetual Challenge of Potential Human Pandemicity

David M. Morens a, Jeffery K. Taubenberger b, Anthony S. Fauci a

Author Affiliations: Office of the Director a, Viral Pathogenesis and Evolution Section,b Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA

Address correspondence to David M. Morens, dmorens@niaid.nih.gov. Editor Arturo Casadevall, Albert Einstein College of Medicine


ABSTRACT

The ongoing H7N9 influenza epizootic in China once again presents us questions about the origin of pandemics and how to recognize them in early stages of development. Over the past ~135 years, H7 influenza viruses have neither caused pandemics nor been recognized as having undergone human adaptation. Yet several unusual properties of these viruses, including their poultry epizootic potential, mammalian adaptation, and atypical clinical syndromes in rarely infected humans, suggest that they may be different from other avian influenza viruses, thus questioning any assurance that the likelihood of human adaptation is low. At the same time, the H7N9 epizootic provides an opportunity to learn more about the mammalian/human adaptational capabilities of avian influenza viruses and challenges us to integrate virologic and public health research and surveillance at the animal-human interface.


FOOTNOTES

Citation Morens DM, Taubenberger JK, Fauci AS. 2013. H7N9 Avian Influenza A Virus and the Perpetual Challenge of Potential Human Pandemicity. mBio 4(4):e00445-13. doi:10.1128/mBio.00445-13.

Published 9 July 2013

Copyright ? 2013 Morens et al.

This is an open-access article distributed under the terms of the Creative Commons Attribution-Noncommercial-ShareAlike 3.0 Unported license, which permits unrestricted noncommercial use, distribution, and reproduction in any medium, provided the original author and source are credited.


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[Pathfinder]

Re: mBio. H7N9 Avian Influenza A Virus and the Perpetual Challenge of Potential Human Pandemicity

Public release date: 9-Jul-2013

Contact: Jim Sliwa
jsliwa@asmusa.org
202-942-9297
American Society for Microbiology

H7N9 influenza: History of similar viruses gives cause for concern

The H7N9 avian flu strain that emerged in China earlier this year has subsided for now, but it would be a mistake to be reassured by this apparent lull in infections. The virus has several highly unusual traits that paint a disquieting picture of a pathogen that may yet lead to a pandemic, according to lead scientists from the National Institute of Allergy and Infectious Diseases. David Morens, Jeffery Taubenberger, and Anthony Fauci, in a paper published in mBio?, the online open-access journal of the American Society for Microbiology, describe the history of H7 viruses in animal and human disease and point out that H7 influenza has a tendency to become established in bird, horse, and swine populations and may spillover repeatedly into humans.

"The evidence as a whole is complex and the implications of past outbreaks for predicting the future course of the current H7N9 epizootic [an epidemic among animals] are uncertain," write the authors. ...

...H7N9 also shares many characteristics with another influenza strain that continues to spillover into humans: highly pathogenic avian influenza H5N1. Among other commonalities, both viruses have a clinical picture that includes bilateral pneumonia, acute respiratory distress syndrome, and multi-organ failure, and it appears they are both currently unable to easily infect most humans but cause severe disease in individuals with uncharacterized genetic susceptibilities.
...
The authors point out that many H7 viruses have adapted to infect mammals, including horses and pigs, which raises the possibility that H7N9 could adapt in a similar fashion. The possibility that H7N9 might infect pigs is particularly troubling, as swine are considered a "mixing vessel" for viruses - a breeding ground for novel viral reassortants like the 2009 H1N1 pandemic influenza strain commonly known as "swine flu".

The sum of these observations is this: we do not know what H7N9 will do next. Although avian influenza viruses have not caused widespread human transmission in 94 years of surveillance, there have been numerous instances of avian influenza spillover and H7N9 "might arguably be more likely than other avian viruses to become human-adapted," write the authors.
...

http://www.eurekalert.org/pub_releases/2013-07/asfm-hih070313.php

[Giuseppe]

Re: mBio. H7N9 Avian Influenza A Virus and the Perpetual Challenge of Potential Human Pandemicity

Hitting the deck, we have NOT any evidence of an ongoing H7N9 poultry epizootic in China, since there are not public data available, except few OIE reports about very few samples positive for the virus.

In a scenario like this, every prediction is hazardous.

If we aim to protect global public health, we must have public data shared timely and honestly.

This is true also for MERS-CoV and other emerging threats.

It is not wise from all stakeholders to conceal information and critical data on these issues.

Then we may call for Emergency international mettings (as seen since 2003 H5N1 panzootics) that are useful only to quell some civil unrests dangers for discredited regimes.

GM

[NS1]

Re: mBio. H7N9 Avian Influenza A Virus and the Perpetual Challenge of Potential Human Pandemicity

Hitting the deck, we have NOT any evidence of an ongoing H7N9 poultry epizootic in China, since there are not public data available, except few OIE reports about very few samples positive for the virus.

In a scenario like this, every prediction is hazardous.

If we aim to protect global public health, we must have public data shared timely and honestly.

. . .

2013-04-14
H7N9 Human Isolates on Deposit at GISAID [Post#68]

Potential Passerine Involvement
as Emergent H7N9
Reservoir

Current emergent H7N9 Hemagglutinin genetic evidence suggests that a wider species list of Passerines should be sampled and sequenced for Influenza A H5 and H7 serotypes in Shanghai, Guizhou, Hong Kong, Japan & Korea, including the following list in order of descending importance:

• Pica pica and other Pica genus species
• Cissa chinensis and other Cissa genus species
• Garrulus lidthi
• Hirundo rustica
• Delichon urbicum

One or more of these Passerine species may presently carry genetics related to the HA emergence.

Detailed surveillance of these species in three areas of Guangdong province may prove beneficial:

• Shenzhen
• Guangzhou
• Huadong

If our public health leaders believe that emergent H7N9 has potential for continued human infection, then additional surveillance is required for the protection of public health.

The quoted Request for Research Information on Passerines was made publicly on 2013-04-14 as part of a series that proposed very targeted and detailed locales, serotypes and species in an effort to reduce collection cost, in-lab sequence extraction burden and time-to-publication.

Related Reading

• GeneWurx Cross Serotype Homology Analysis, Open-Access, Full-Text version
• Human Emergent H7N9 from Zhejiang Province
• Environment Emergent H7N9 from Zhejiang
• Fatal H5N1 Homology to Emergent H7N9 from Shanghai in March
• Mammalian Adaptation of Emergent H7N9 Neuraminidase in Jiangsu
• TamiFlu Resistance via NA 292K in Taiwan and Shanghai
• Zhejiang Fatal H7N9 with Divergent NA, PB2 701N and Aberrant PA
• Novel PB2, Divergent PB1 & Novel PA from First Fujian Case
• China - H7N9 Human Isolates on Deposit at GISAID, Comprehensive Genetics Discussion

[NS1]

Re: mBio. H7N9 Avian Influenza A Virus and the Perpetual Challenge of Potential Human Pandemicity

Notable Absence

Ongoing 2013
H7N3 Outbreak
throughout
Mexico

Hitting the deck, we have NOT any evidence of an ongoing H7N9 poultry epizootic in China, since there are not public data available, except few OIE reports about very few samples positive for the virus.

GM

Citation

Morens DM, Taubenberger JK, Fauci AS. 2013. H7N9 Avian Influenza A Virus and the Perpetual Challenge of Potential Human Pandemicity. mBio 4(4):e00445-13. doi:10.1128/mBio.00445-13.

Over recent decades, both HPAI and low-pathogenicity avian influenza (LPAI) H7 viruses have caused numerous explosive poultry outbreaks, notably massive 1999 H7N1 HPAI and 2003 H7N3 LPAI outbreaks in Italy (12, 13), a 2003 H7N7 HPAI outbreak in the Netherlands (14, 15), 2004 and 2007 HPAI H7N3 outbreaks in Western Canada (16), a 2012 HPAI H7N3 outbreak in Mexico (17), and ongoing enzootic circulation of H7N2 viruses in bird markets in New York (18).

A curiousity is evident due to absence.

Following Giuseppe Michieli's thought process and mention of the OIE reports, we recalled the 2013 HPAI outbreaks of H7N3 Avian Influenza on commerical farms throughout the US border nation of Mexico. The authors of this paper temporally cataloged H7 outbreaks around the world starting several decades in the past and ending with one current and ongoing H7N2 enzootic in New York. The start of the current ongoing Mexican H7N3 series of outbreaks is penultimately mentioned in the progressive list as a 2012 event as if the matter only occurred in the past and was effectively closed in 2012?

A review of the OIE reports made by the Mexican SENASICA and reported secondarily by the American CIDRAP demonstrates essential information concerning the H7N3 serotype, a reservoir that has been previously implicated in formation of the emergent H7N9 Hemagglutinin antigens. No less than 61 outbreaks of H7N3 Avian Influenza are documented in 9 OIE reports throughout most of Mexico from January to June 2013.

The SENASICA report of 2013-06-12 to OIE indicates that "The event is continuing."

Vaccinated flocks with asymptomatic HPAI carriers are found among the 2013 outbreaks in Mexico using serology-based surveillance. Some concern comes into play when a superspread situation is occuring and the carriers do not exhibit symptoms or define themselves clinically as infected. Concern rises when the discussion of event progression is truncated.

This type of information may be found in the future to be of considerable importance for Mexican and American citizens.

Related Reading

• GeneWurx Cross Serotype Homology Analysis, Open-Access, Full-Text version
• Human Emergent H7N9 from Zhejiang Province
• Environment Emergent H7N9 from Zhejiang
• Fatal H5N1 Homology to Emergent H7N9 from Shanghai in March
• Mammalian Adaptation of Emergent H7N9 Neuraminidase in Jiangsu
• TamiFlu Resistance via NA 292K in Taiwan and Shanghai
• Zhejiang Fatal H7N9 with Divergent NA, PB2 701N and Aberrant PA
• Novel PB2, Divergent PB1 & Novel PA from First Fujian Case
• China - H7N9 Human Isolates on Deposit at GISAID, Comprehensive Genetics Discussion