May 7, 2024 - Health

Charted: Where bird flu has been detected in wild mammals

A map of the United States shows counties where avian flu has been detected in wild mammals. The disease is widespread, particularly across New England, the upper midwest, Colorado and the Pacific northwest. It's been prevalent in red foxes but has also been found in a dolphin in Florida and a polar bear in Alaska.
Data: USDA; Map: Danielle Alberti/Axios

The bird flu outbreak in dairy cattle doesn't currently pose a risk to the public, but experts say detecting viral spread early and limiting how long it circulates in a population of animals cuts the odds it will jump to new species.

  • The current version of H5N1 flu has been in circulation since 2021 and infected a range of animals, and is already in more than 30 herds.
  • One scenario that concerns public health officials is if the virus in cows mixes with influenza viruses that are endemic to pigs. Swine are well-known "mixing bowls" for viruses that can eventually jump to humans, experts say.
  • A United States Department of Agriculture spokesperson told Axios there currently is no indication the virus is infecting pigs and that the department works with animal health officials and farming interests to conduct surveillance.
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