Health leaders lay out their concerns about the new H7N9 bird flu

[Shiloh]

Source: http://www.ctvnews.ca/health/health-leaders-lay-out-their-concerns-about-the-new-bird-flu-1.1223628


Health leaders lay out their concerns about the new bird flu
Helen Branswell, The Canadian Press
Published Thursday, April 4, 2013 7:13AM EDT

TORONTO -- Three sick people. That's all it took to make scientists who study influenza edge-of-seat nervous this week over a rapidly evolving public health situation in China.

Though the case count is now up to nine infections and three deaths, those first three sick people and the genetic sequences of the flu viruses that infected them were enough to make the hairs on the backs of knowledgeable necks stand on end.

Four years to the month after H1N1 swine flu marched into the global consciousness, a new avian virus, an H7N9, came out of nowhere to demand attention.

While it's too soon to say if these are the first halting steps of a new pandemic virus, at this point flu experts would not bet against H7N9...

 

[NS1]

Re: Health leaders lay out their concerns about the new H7N9 bird flu

We are grateful to the samplers, the depositing labs and the GISAID consortium for making the small batch of evaluation material available on 2013-03-31 during this zoonotic epidemic emergence of H7N9 that has the very unfortunate combination of a High Case Fatality Rate and Low clinical intervention effectiveness [GISAID Citations].

The H7N9 human cases show clinically and experimentally-confirmed Gain of Function traits on a minimum of 3 gene segments:

• Hemagglutinin 226L
• Neuraminidase aa69-73 stalk deletion (15 base)
• Polymerase Basic 2 627K

The H7N9 sequences are related at the polymorphism level to widely circulating human virus patterns including pH1N1, sH3N2 and to fatal human H5N1. Each component of the H7N9 human cases carries sub-segment genetics that have seen mammalian adaptation, including the external proteins, Hemagglutinin and Neuraminidase.

An up-to-date and comprehensive follow-up evaluation for each HA polymorphism found on the 3 human H7N9 sequences was provided Wednesday, 2013-04-03, demonstrating the Cross Serotype Homology details. The preliminary H7N9 Novelty Evaluation and Relationship Potential to pH1N1 with detailed Hemagglutinin amino-level polymorphism surfacing was made available for preview on 2013-03-31, formalised at midnight and is now being versioned.

Genetic specifics concerning animal origins and human / mammal adaption are under analysis. The full text of those intermediate reports are currently in pre-publication viewing status and are available at the following links. These compilations will be updated as labs release new sequences.

• GeneWurx Human Emergent H7N9 Cross Serotype Homology (External Genes)
• GeneWurx Human Emergent H7N9 Rare and Novel Hemagglutinin Antigens (External Genes)
• GeneWurx Human Emergent H7N9 ReAssortment Assessment (Internal Genes)

Additional sequences from early emergence fatal and recovered cases are critical to understanding the immune dynamics required for establishing a bulkhead toward the protection of public health.