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A new-to-humans flu virus killed a 73-year-old woman from the Jiangxi province in China, on Dec. 6.
At the time, the doctors knew it was a H10N8 bird flu virus that killed her. But, they've just published new findings about it — it has picked up some new genes from the H9N2 flu virus. And these genes could make it more dangerous to humans.
"A second case of H10N8 was identified in Jiangxi Province on Jan. 26," study author Mingbin Liu said in the news release. "This is of great concern because it reveals that the H10N8 virus has continued to circulate and may cause more human infections in the future."
They published their results in the journal The Lancet on Feb. 5.
The death was the third in 2013 from a new strain of bird flu virus that had never infected people. The others were the new H7N9 virus and and H6N1 virus.
A mysterious death
The woman in question had recently visited a live poultry market, which is probably where she got the virus. She had been admitted to the hospital on Nov. 30 with severe pneumonia.
A second patient was reported in January, but she is in stable condition in the hospital, according to the WHO. Luckily, none of the people either patient had been in contact with were sickened, suggesting the virus can't spread easily between people yet.
When they sequenced the virus from the first patient, they found that it had several genes from a different kind of flu virus, H9N2. These genes are very similar to those in the human-infecting versions of H5N1 and H7N9, according to the Center for Infectious Disease Research and Policy, at the University of Minnesota.
The virus also has a genetic mutation that was previously linked with increased virulence in mammals, the researchers said.
An increase in new bird flu viruses being detected in humans could be a result of the Chinese government's increased surveillance for avian flu infections after the arrival of H7N9, according to the Center for Infectious Disease Research And Policy at the University of Minnesota. That means authorities are more likely to test for and report infections with these viruses.
We probably missed these infections before, only realizing a new virus had jumped to humans when it reached a larger scale. Science journalist Alan Dove wrote on Twitter back when the case first broke: "People have probably been dying of sporadic bird flu spillovers for eons, but we only noticed the ones that became pandemics."
Though it might result in some scare-tactics from the media, watching and monitoring these small outbreaks isn't necessarily a bad thing. We can now watch these infections before they kill hundreds of people, and track if they are getting worse.
A tale of three bird flus
In addition to H10N8, the bird flu strain H6N1 also infected a human for the first time in 2013. That patient made a full recovery after a stint in the hospital, and doesn't seem to have infected others, and no other people have shown up infected with the virus.
A much bigger deal is the H7N9 bird flu that has been making a comeback. It was also first found in humans in April 2013. More than 250 patients ended up in hospitals and more than 70 died. While there was a lull in infections with the virus, it is again on the rise.
The original bird flu virus, H5N1, is also still circulating in China and other areas of Asia, where it's sickened many people in Cambodia and Indonesia, according to the WHO. Other viruses currently circulating in Asia include the swine flu H1N1, the "normal" human flu H2N3, and select strains of Influenza B, a related virus.
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