Influenza A (H5N1)
Highly Pathogenic Avian Influenza - H5N1
In April 2022, an individual in Colorado was confirmed by the Centers for Disease Control and Prevention (CDC) as the first human case of HPAI A(H5N1) virus in the U.S. Human infections with avian influenza A viruses, including A(H5N1) viruses, are uncommon but have occurred sporadically worldwide.
However, in the United States, since 2022, HPAI A(H5N1) virus detections have been reported in more than 200 mammals. On April 1, 2024, the CDC confirmed a positive human case of influenza A(H5N1) virus in the United States in a person with exposure to dairy cows. It is the first known case of human infection from contact with an infected mammal.
Since April 2024, 25 human cases of avian influenza A(H5) virus infection have been reported in the United States. Fifteen of these cases were associated with exposure to sick dairy cows and nine were associated with exposure to avian influenza A(H5N1) virus-infected poultry. The source of the exposure in a case reported by Missouri has not been determined.
As of October 2024, 319 dairy herds in 14 U.S. states have confirmed cases of H5 bird flu virus infections in dairy cows and 48 states have reported outbreaks in poultry.
The CDC tracks and reports confirmed cases, by state and source of exposure, in a table on its website: https://www.cdc.gov/bird-flu/situation-summary/index.html. The CDC has recommendations for clinicians on monitoring, testing, and antiviral treatment for patients with suspected or confirmed avian influenza A virus infections.
Read an opinion article by Jennifer B. Nuzzo, Lauren Sauer, and Nahid Bhadelia in the Washington Post discussing how "If many dairy farm workers contract H5N1, we risk a pandemic."
Unofficial Map of H5N1 cases around the globe by the University of Nebraska Medical Center's Global Center for Health Security
NETEC Online Courses
External Resources
NETEC Novel Respiratory Pathogen Flyers and Checklists
Laboratory Resources
Personal Protective Equipment Resources
Infection Prevention and Control Resources
Patient Care Resources
EMS Resources
Personnel Management Resources
Emergency Management Resources
Spanish Language Novel Respiratory Pathogen Flyers
