Bird flu emergency response ends in US as infections decline

The U.S. Centers for Disease Control and Prevention ended its emergency response for bird flu as the outbreak that sickened dozens of people, spread to cattle and drove up egg prices has abated.

The emergency designation ended in the last week, according to a person familiar with the matter who wasn’t authorized to speak publicly about it.

The CDC merged its bird flu updates with those routinely reported for seasonal influenza starting on Monday, and will post the number of people monitored and tested for the virus also known as H5N1 on a monthly basis, the agency said. It will no longer include infection rates found among animals on its website.

States that were among the hardest hit have also dialed back their efforts. California ended its emergency declaration in April, a spokesperson for the Department of Public Health told Bloomberg. Washington, which had 11 human cases in 2024, is also downsizing its response, state epidemiologist Scott Lindquist said.

The CDC’s emergency bird flu response was deactivated to transition back to regular program activity, according to a spokesperson for the Department of Health and Human Services. Surveillance, readiness and response for bird flu will be included with existing efforts from the CDC’s Influenza Division and other agency programs, they said.

Hard to Spot

While the states said they’re still monitoring bird flu activity and will coordinate with federal officials, doctors and researchers said the moves will make it harder to detect potentially dangerous changes. If the virus continues to jump between species or the human case count grows, there’s a greater risk that it could mutate and become more easily transmissible between people, they said.

“We are letting our guard down,” said Michael Kinch, an infectious disease expert and chief innovation officer at Stony Brook University in New York.

Ending the emergency response comes amid a broader federal pullback from preparing for another outbreak. Earlier this year, the U.S. Department of Health and Human Services canceled a $766 million federal contract with Moderna Inc. to develop mRNA vaccines for bird flu.

A CDC emergency declaration redirects people and resources to increase testing, surveillance and communications during an outbreak. During the H5N1 response, 375 staff members from the CDC were assigned to work on the outbreak, the HHS spokesperson said.

Reducing attention to the virus could leave a gap when it is still circulating in migratory birds in the U.S., health experts said.

“If you do miss an uptick, then you’ll be one step behind and then that could lead to more widespread transmission and more herds being infected, more people being infected,” said Dean Blumberg, head of pediatric infectious disease at University of California, Davis.

The CDC previously held regular calls with the U.S. Department of Agriculture, the Administration for Strategic Preparedness and Response and the White House to update the press and epidemiologists on the status of the virus and the federal response. The calls ended before President Trump’s inauguration in January.

Declining Infections

Other factors may also hinder efforts to identify and track infections. Most of the human infections detected in the U.S. occurred among agricultural workers who were in close proximity to sick dairy herds and poultry. State governments and farm owners have to invite CDC investigators to conduct surveillance, a difficult proposition to reach migrant workers during mass immigration raids across the country.

California, which had the highest human case count in 2024 with 38 people infected, started offering $25 gift cards as an incentive to get people to test for influenza A, the flu strain that contains H5N1, in April.

Bird flu started circulating among cattle last year, and eventually led to 70 infections in people confirmed by the CDC. Signs include flu-like symptoms and conjunctivitis, and it can be treated with the anti-viral medication Tamiflu. While one person died from the disease in January, the current risk to humans remains low, the CDC says.

(With assistance from Michelle Amponsah and Ilena Peng.)