A broad coalition of environmental, health, and animal groups is demanding greater transparency from the U.S. Centers for Disease Control and Prevention when it comes to disseminating information about H5N1, or bird flu, that has sickened hundreds of dairy cattle herds, killed millions of chickens, and also infected dozens of humans.
The Monday letter, which was signed by two staff members at the Center for Biological Diversity on behalf of a larger group that includes Earthjustice, the Animal Legal Defense Fund, the Institute for Agriculture and Trade Policy, and others, was sent to CDC acting Director Susan Monarez.
"New information and transmission countermeasures can and must be developed and shared as rapidly as the virus evolves," according to the letter, which says that it has been over a month since the CDC issued a regular update about its bird flu response activity.
On the CDC's "News & Spotlight" page on the section of its website dedicated to bird flu, no update has been posted since January 17. Prior to that date, the page featured regular updates, such as a post about the agency's accomplishments related to curbing bird flu in 2024-25.
Also, the CDC "appears to have delayed or denied the publication of key scientific research on avian influenza in its Morbidity and Mortality Weekly Report, including a study suggesting that infected house cats may be transmitting [highly pathogenic avian influenza] to humans," according to the letter. The letter links to February 6 reporting from The New York Times, which says that the CDC briefly posted but then took down a report that discussed cases of potential human-to-cat and cat-to-human transmission of bird flu.
That report now appears online and was posted as part of the CDC's Morbidity and Mortality Weekly Report for February 20.
"This is exactly the kind of information that concerns the public and should have been shared broadly—not withheld—so that Americans could avoid this route of infection and researchers and public health officials could understand and defeat this virus," the letter states.
According to the authors of the letter, publicizing data about bird flu is crucial, especially given reports of federal personnel cuts potentially impacting the government's bird flu response. Last week, the U.S. Department of Agriculture said it had sent termination letters to "several" staff working on the government's bird flu response, and that the agency was working to reverse the firings.
"The CDC should release to the public all information related to the avian influenza outbreak as soon as it is confirmed. This commitment to public transparency is essential to an effective, whole-of-society response to this growing disease threat," the letter concludes.
