Humans and animals can come into contact with the virus by interacting with infected birds and contaminated surfaces or by breathing in air containing the virus.

According to the Centers for Disease Control, bird flu viruses (including H5N1) can be transmitted to humans and animals through contact with infected birds, which shed the virus in their saliva, waste and mucus. Humans and animals can come into contact with the virus by interacting with infected birds and contaminated surfaces, breathing in air containing the virus and eating undercooked birds and eggs. Animals that are infected with the virus can also spread the virus to humans via bodily fluids and meat, including raw milk and beef.

While the CDC notes that human-to-human transmission of bird flu viruses is rare, it has happened in previous outbreaks in other countries. According to the Minnesota Department of Health, the H5N1 bird flu virus was found in dairy cattle in Minnesota in June 2024. No human cases or human-to-human transmissions have yet been reported within the state.