Bird Flu (Avian Influenza)

Page originally published 5/1/2024. Last updated 2/21/2025.

Bird flu, also known as avian influenza A (H5N1) or highly pathogenic avian influenza (HPAI), is a disease caused by infection with a type of flu virus. These viruses happen among water birds, like ducks and geese. They can also spread to domestic poultry, like chickens and turkeys, in addition to wild and domestic mammals (such as cattle and cats). Although bird flu does not usually make people sick, there have been some rare cases.

While the current risk to the public remains low, the County of San Diego is monitoring the situation and working to protect the public’s health.

Call the Epidemiology Unit at (619) 692-8499, or send an email, for more information