Tuesday, April 12, 2022

New Avian Flu Virus: Eurasian H5N1 - How Much Should Americans Be Concerned?

 

                                        Micrograph of H5 N1 (Avian influenza) virus

The latest Avian flu outbreak  - affecting farms and flocks form Maine to Wyoming- is nothing to ignore, but how much should Americans be concerned?.  For perspective, the last outbreak in 2014-15  saw nearly 50 million birds perish from the disease which was blamed for $3 billion in losses. It devastated the agricultural industry and was regarded as the most destructive outbreak in history.   

The virus is highly contagious - rivaling the BA.2 Covid in humans- but much more lethal.  It can prey on chickens, turkeys and wild birds - such as ducks and geese- which can carry it long distances.  It spreads via nasal secretions, saliva and fecal droppings, which experts say makes it difficult to contain. A few of the primary early symptoms include diminished consumption of food and water and a drop in egg production. 

Currently, the most significant effect for humans is the drop in egg production and the resulting inflation. Given that nearly 14 m egg-laying birds have either died from the virus or had to be slaughtered, the wholesale price for large, Midwest -shell eggs is now nearly three times as much as last year.  The cost of a dozen surpassed $3 barely two weeks ago and likely to be even more expensive just before Easter. At our local Safeway we're coughing up $3.69 for a dozen 'Jumbo' eggs, so I am more and more limiting to one egg at a time.

 The virus responsible: Eurasian H5 N1, is closely related to an Asian strain that's infected hundreds of people since 2003 with a fatality rate near 60 %. Most of the victims worked with infected poultry, or came into contact with infected workers.   The presence of the virus in the States is not unexpected given outbreaks have previously been reported in Europe, the Middle East.  

At least one specialist quoted in a recent NY Times piece observed that  "it's not impossible for humans to get the virus, but it's been pretty rare.".  But that should not breed complacency. 

Almost exactly 9 years ago a report appeared in The Milwaukee Journal -Sentinel concerning emergence of a new avian flu strain. Word, for word, it reported:


"Genetic analysis of the H5 N1 avian flu virus responsible for at least nine human deaths in China portrays a virus evolving to adapt to human cells, raising concern about its potential to spark a new global flu pandemic."

The collaborative study, conducted by a group led by Masato Tashiro of the Influenza Virus Research Center, National Institute of Infectious Diseases, and Yoshihiro Kawaoka of the University of Wisconsin-Madison and the University of Tokyo, appears in the current edition of the journal Eurosurveillance. The group examined the genetic sequences of H7N9 isolates from four of the pathogen's human victims as well as samples derived from birds and the environs of a Shanghai market.

"The human isolates, but not the avian and environmental ones, have a protein mutation that allows for efficient growth in human cells and that also allows them to grow at a temperature that corresponds to the upper respiratory tract of humans, which is lower than you find in birds," Kawaoka, a leading expert on avian influenza, said at that time in a news release from UW-Madison.

My take, given the H5N1 would (from cases analyzed thus far) incept a "cytokine storm" in humans - similar to what the H1N1 Spanish Flu did, is that at least 500 million would perish, and possibly as many as 1 billion.  That means that although a human H5 N1 pandemic may be unlikely we can't let our guard down - especially as a new Covid variant BA. 2 is also ramping up.  

Reinforcing my take, Dr. Andrew Bowman, quoted in the same NY Times piece, has raised concerns over the geographic spread in the new outbreak.  In  his words: "I think we're certainly seeing more geographic spread than what we saw with the 2014-15 outbreak."   Let's bear inn mind as Laurie Garrett has pointed out ('The Coming Plague')  a wider geographic spread generally is a harbinger for increased virus mutation, i.e. among millions more  birds.  We had better keep our vigilance, and our N95 masks ready - as these viruses may not be done with us yet!


See Also:

https://www.cdc.gov/flu/avianflu/avian-in-humans.htm

And:

by William Rivers Pitt | April 12, 2022 - 6:13am | permalink

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