May 8, 2024 - News

How Colorado is working to limit the avian flu outbreak

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 affecting dairy cattle in Colorado doesn't currently pose a risk to the public.

State of play: The virus, first detected in Colorado cattle in April, led the state agricultural commission to adopt a federal rule last week that requires mandatory testing of lactating dairy cattle moving between states.

  • That will help limit the flu's spread and protect the poultry and dairy industry, state agricultural commissioner Kate Greenberg said in a statement.

Threat level: The virus causes serious illness and even death for poultry like chickens, turkeys and ducks, according to a statement from the Colorado Department of Agriculture.

Yes, but: It doesn't appear to make cows severely sick, according to the Denver Post.

By the numbers: Colorado is home to 106 dairies and roughly 200,000 dairy cows, per the state agriculture department.

Context: The current version of the avian flu, H5N1, has been in circulation since 2021 infecting a range of animals, and is currently in more than 30 herds.

  • One scenario that concerns public health officials is if the virus in cows mixes with influenzas that are endemic to pigs. Swine are well-known "mixing bowls" for viruses that can eventually jump to humans, experts say.

What we're watching: A USDA spokesperson told Axios there's no indication the virus is actively infecting pigs.


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