Oct 11, 2023 - News

Bird flu shows up in Washington seals, alarming scientists

Over 60 million birds have died or been killed as the result of a new strain of highly pathogenic avian influenza. The outbreak is the worst in U.S. history. Photo: Jim Watson/AFP via Getty Images

An outbreak of bird flu has spread to harbor seals off the coast of Washington in the first documented instance of marine mammals dying from the disease on the West Coast.

Driving the news: The highly pathogenic H5N1 flu strain was detected in dead harbor seals on Marrowstone Island off the east coast of the Olympic Peninsula, according to the National Oceanic and Atmospheric Administration.

Why it matters: The increase in H5N1 avian influenza detections among mammals raises concern that the virus might adapt to infect humans more easily, according to a statement from the World Health Organization.

  • Some mammals may act as mixing vessels for flu viruses, leading to the emergence of new strains that could prove more harmful to humans, WHO said.
  • In Montana, three grizzly bears have also tested positive for the avian flu strain.

The takeaway: Public health experts at the Washington Department of Health and the University of Washington are urging people to keep themselves and their pets a safe distance from sick animals.

  • Infected birds shed the virus in their saliva, mucus and feces and people can become infected if the virus gets into their eyes, nose, mouth or lungs, per the state Department of Health.

What they're saying: "The number of countries involved, the number of different types of animals involved, both birds and mammals, is something we've absolutely never seen before," said Peter Rabinowitz, a professor in the University of Washington schools of Medicine and Public Health.

The big picture: The current outbreak is the worst in U.S. history, with more than 60 million birds dead at the beginning of this year from either the virus or preventive culling.

  • In Washington, the first case of the H5N1 strain was reported in May 2022.

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