What is bird flu or highly pathogenic avian influenza (HPAI) A(H5N1)?
Bird flu (H5N1) is caused by an infection with avian influenza type A viruses, which primarily spread among wild aquatic birds and can infect other animals. Highly pathogenic avian influenza (HPAI) viruses cause severe disease and high mortality in infected poultry.
In late March 2024, a human case of influenza A(H5N1) virus infection was identified after exposure to dairy cows presumably infected with bird flu. CDC has reported additional, sporadic human cases in people who had exposure to infected dairy cows. According to the CDC, the current risk to the general public is low.
Learn more from the AMA on questions patients may have and how to answer.
Featured updates
- Jan. 16, 2025: CDC Health Alert Network (HAN) Health Advisory: Accelerated Subtyping of Influenza A in Hospitalized Patients
- Sept. 6, 2024: Human H5 bird flu case confirmed in Missouri, without animal exposure
- July 16, 2024: COCA Call: Update on Highly Pathogenic Avian Influenza A(H5N1) Virus for Clinicians and Healthcare Centers: Access webinar recording. Presenters give an update on the current outbreak in the United States and current CDC surveillance and monitoring efforts. They provide information for clinicians on testing, using antivirals, and infection prevention and control recommendations. Registration is not required. Continuing education offered.
- July 3, 2024: CDC Reports Fourth Human Case of H5 Bird Flu Tied to Dairy Cow Outbreak
- May 22, 2024: H5N1 Bird Flu: Current Situation Summary
- April 5, 2024: CDC Health Alert Network (HAN) Health Advisory: Highly Pathogenic Avian Influenza A (H5N1) Virus: Identification of Human Infection and Recommendations for Investigations and Response
Clinical information and resources from the AMA
Stay updated on bird flu (H5N1).
Federal resources
CDC advice for clinicians on raw milk and bird flu (PDF)
FDA updates on avian flu
USDA bird flu in livestock detection guidance
AMA video updates
What you need to know about bird flu
Vice President of Science, Medicine and Public Health, Andrea Garcia, JD, MPH, discusses the latest news.
2025 video updates
- April 23, 2025: Update from the World Health Organization
- Feb. 19, 2025: New bird flu cases in the U.S.
- Feb. 5, 2025: Rare bird flu strain in poultry
- Jan. 29, 2025: New bird flu outbreak in California
- Jan. 22, 2025: Details on the CDC alert
- Jan. 8, 2025: First severe case of bird flu
- 2024 video updates
- Dec. 4, 2024: Bird flu in California
- Nov. 20, 2024: Update on bird flu cases
- Oct. 30, 2024: Bird flu symptoms in humans
- Oct. 2, 2024: Bird flu in Missouri
- Sept. 18, 2024: Bird flu CDC update
- Sept. 11, 2024: Human case of bird flu in Missouri
- Aug. 7, 2024: A look at human cases of bird flu in in the U.S.
- July 17, 2024: Update on H5N1
- July 10, 2024: Which states have bird flu
- July 3, 2024: A new study on bird flu in cows and state fair safety
- June 28, 2024: CDC guidance on H5N1 outbreak
- June 19, 2024: Latest on bird flu
- May 29, 2024: Bird flu in milk: Raw milk vs. pasteurized milk
- May 22, 2024: Bird flu raw milk dangers
- May 15, 2024: CDC wastewater surveillance for bird flu
- May 8, 2024: How does bird flu spread?
