Research shows Alaska Native, Australian indigenous groups’ isolation from flu

H7N9 Lab

A CDC Scientist harvests H7N9 virus that has been grown for sharing with partner laboratories for research purposes. Photo courtesy of the Centers for Disease Control.

Indigenous populations in Alaska and Australia may be vulnerable to influenza, particularly a recent form of bird flu.

Since the first break-out of H7N9 in China early last year, 150 people have been infected and 45 people have been killed. Two people died earlier this month. It’s called bird flu since people have obtained the virus from domesticated poultry.

Although there does not currently appear to be a sustainable person-to-person transmission of H7N9, scientists and health officials worry that will eventually happen with further mutations of the virus. That potential person-to-person transmission is what worries researchers like Katherine Kedzierska, Associate Professor of Microbiology and Immunology and laboratory group head at the University of Melbourne in Australia. She was also senior author of the study that was published last month in the Proceedings of the National Academy of Sciences that examined possible pre-existing cellular immunity among various human ethnic groups.

“This immunity really depends on the genetic make-up of the individual,” said Kedzierska.


H7N9

Influenza A H7N9 as viewed through an electron microscope. Both filaments and spheres are observed in this photo. Photograph courtesy of CDC.

 

Kedzierska said indigenous populations in Alaska and Australia would likely be very vulnerable to latest strains of flu. They have been relatively isolated and have not had the exposure to various influenza viruses that were identified as circulating in Greece as early as two millennia ago.

“So, (Europeans) had centuries of evolutionary pressures from viruses like these to develop all the mechanisms to protect and fight the viruses,” said Kedzierska.

The research also provides some clues about the 1918 influenza outbreak.

“We think it was a new virus entering the human circulation,” said Kedzierska. “So, that’s why we didn’t have much immunity and that’s why it was catastrophic, more than 40 million people die around the globe.”

It also sheds some light on why mortality rates were so high among Alaska Natives during the 1918 outbreak.

We know that in some isolated Alaskan villages (that) up to 100 percent of adults have died. Similarly, in the Australian indigenous population, we had higher mortality rates. Ten to 20 percent of the Australian indigenous population died of this influenza and this is comparing to less than 1 percent of non-indigenous Australians. So, we know from history that this had happened before when we have a new influenza strain emerging and entering the human circulation.”

Link to published paper in Proceedings of the National Academy of Sciences: Preexisting CD8+ T-cell immunity to the H7N9 influenza A virus varies across ethnicities

Link to page of frequently asked questions about H7N9 influenza from the Centers for Disease Control: H7N9 FAQ

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