Pathfinder
Editor, Senior Moderator
What happened to bird flu? How a major threat to human health faded from view
By HELEN BRANSWELL FEBRUARY 13, 2019
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It?s not just H5N1 that has dissipated. The virus?s nearly-as-scary cousin, H7N9, emerged in China in 2013 and sickened more than 1,500 people in China over five years, killing roughly 40 percent of them.
But after an extraordinary surge of cases ? 766 ? in early 2017, there were a mere three infections recorded in 2018. So far in 2019 there have been none.
Although there are ways to make sense of H7N9?s decline, no one knows precisely why H5N1 has faded from view.
...
Scientists do know the H5N1 viruses have mutated in ways that may be important to their ability to interact with people. Several years ago, these viruses effectively splintered, with some dumping their N1 neuraminidase ? a gene that produces a key protein found on the surface of flu viruses ? and replacing it with another. The process is called reassortment, and, in this case, it resulted in the emergence of a lot of new pairings over a fairly short period of time.
The most common and most dangerous viruses to emerge ? for birds at least ? have been H5N6 and H5N8 viruses. Both are highly pathogenic, meaning they kill domestic poultry.
?The H5N1 virus has not gone away. It?s just changed into different versions of itself,? explained influenza expert Malik Peiris, a professor of virology at the University of Hong Kong.
?We don?t know how the story?s going to end.?
...
https://www.statnews.com/2019/02/13/bird-flu-mutations-outlook/
By HELEN BRANSWELL FEBRUARY 13, 2019
...
It?s not just H5N1 that has dissipated. The virus?s nearly-as-scary cousin, H7N9, emerged in China in 2013 and sickened more than 1,500 people in China over five years, killing roughly 40 percent of them.
But after an extraordinary surge of cases ? 766 ? in early 2017, there were a mere three infections recorded in 2018. So far in 2019 there have been none.
Although there are ways to make sense of H7N9?s decline, no one knows precisely why H5N1 has faded from view.
...
Scientists do know the H5N1 viruses have mutated in ways that may be important to their ability to interact with people. Several years ago, these viruses effectively splintered, with some dumping their N1 neuraminidase ? a gene that produces a key protein found on the surface of flu viruses ? and replacing it with another. The process is called reassortment, and, in this case, it resulted in the emergence of a lot of new pairings over a fairly short period of time.
The most common and most dangerous viruses to emerge ? for birds at least ? have been H5N6 and H5N8 viruses. Both are highly pathogenic, meaning they kill domestic poultry.
?The H5N1 virus has not gone away. It?s just changed into different versions of itself,? explained influenza expert Malik Peiris, a professor of virology at the University of Hong Kong.
?We don?t know how the story?s going to end.?
...
https://www.statnews.com/2019/02/13/bird-flu-mutations-outlook/