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CDC provides an update on its response activities related to the multistate outbreak of avian influenza A(H5N1) virus, or "H5N1 bird flu," in dairy cows and other animals in the United States.

SEE: U.S. Centers for Disease Control and Prevention

(CDC) A(H5N1) Bird Flu Response Update November 18, 2024 | Bird Flu | CDC

https://www.cdc.gov/bird-flu/spotlights/h5n1-response-11152024.html

Situation Update

November 18, 2024 – CDC continues to respond to the public health challenge posed by a multistate outbreak of avian influenza A(H5N1) virus, or "H5N1 bird flu," in dairy cows, poultry and other animals in the United States. CDC is working in collaboration with the U.S. Department of Agriculture (USDA), the Food and Drug Administration (FDA), Administration for Strategic Preparedness and Response (ASPR), state public health and animal health officials, and other partners using a One Health approach.

Since April 2024, CDC, working with state public health departments, has confirmed avian influenza A(H5) virus infections in 52 people in the United States. Twenty-one of these cases were associated with exposure to avian influenza A(H5N1) virus -infected poultry and 30 were associated with exposure to infected dairy cows [A][B]. The source of the exposure in one case, which was reported by Missouri on September 6, could not be determined.

The 52 cases include 26 cases among dairy farm workers in California, five of which were confirmed by CDC on November 13 and 14, and one additional case in a poultry farm worker in Oregon. This is the first human case of H5N1 bird flu reported in Oregon. All recent cases have occurred in workers on affected farms. All available data so far suggest sporadic instances of animal-to-human spread. These farm workers all described mild symptoms, many with eye redness or discharge (conjunctivitis). Some workers who tested positive in Washington reported some mild upper respiratory symptoms. None of the workers were hospitalized.

CDC is aware of the human case of H5N1 bird flu reported in Canada and is in communication with the Public Health Agency of Canada (PHAC), which has confirmed that the case was caused by an H5N1 virus that is different than those causing outbreaks in dairy cows and other animals in the United States. More information about the case in Canada and ongoing epidemiological investigation is available in a statement from PHAC. Updated case counts for the United States, including by state and source of exposure, are recorded in a table on CDC's website. To date, person-to-person spread of H5 bird flu has not been identified in the United States. CDC believes the immediate risk to the general public from H5 bird flu remains low, but people with exposure to infected animals are at higher risk of infection.

On the animal health side, since March 2024, USDA has confirmed infected cattle in 505 dairy herds in 15 U.S. states. The number of affected herds continues to grow nationally, with almost all new infections identified in herds in California. USDA reports that, since April 2024, there have been H5 detections in 50 commercial poultry flocks and 38 backyard flocks, for a total of 25.61 million birds affected.  ...

... CDC Recommendations

• People should avoid exposures to sick or dead animals, including wild birds, poultry, other domesticated birds, and other wild or domesticated animals (including cows), if possible.
• People should also avoid exposures to animal poop, bedding (litter), unpasteurized ("raw") milk, or materials that have been touched by, or close to, birds or other animals with suspected or confirmed avian influenza A(H5N1) virus, if possible.
• People should not drink raw milk. Pasteurization kills avian influenza A(H5N1) viruses, and pasteurized milk is safe to drink.
• People who have job-related contact with infected or potentially infected birds or other animals should be aware of the risk of exposure to avian influenza viruses and should take proper precautions. People should wear appropriate and recommended personal protective equipment when exposed to an infected or potentially infected animal(s). CDC has recommendations for worker protection and use of personal protective equipment (PPE).
• CDC has interim recommendations for prevention, monitoring, and public health investigations of avian influenza A(H5N1) virus infections in people.

Following these recommendations is central to reducing a person's risk and containing the overall public health risk.

In addition to limiting interactions between infected animals and people, containing the outbreak among animals also is important, which underscores the urgency of the work being done by USDA and animal health and industry partners.

This is an evolving situation and CDC is committed to providing frequent and timely updates.