Avian (Bird) Flu: HPAI H5N1

What is it?

Bird flu, also known as avian influenza A (H5N1) or highly pathogenic avian influenza (HPAI), is caused by a virus that can cause serious illness and death in birds and mammals. Human infections with bird flu viruses are rare, but they can happen when the virus gets into a person's eyes, nose, mouth, or when inhaled.

CDC: National Data

As of 12/11/24, there are 2 confirmed cases in the county.

Local monitoring -- This CDPH site monitors wastewater data for flu virus (which includes H5N1):
California Wastewater Surveillance Network Dashboard 

  • The risk to the public remains low at present
  • No human-to-human transmission of bird flu has been detected in California
  • Humans rarely contract bird flu. A greater risk lies with those who have regular contact with infected dairy cows, poultry, or wildlife. This includes contact with animal fluids, feces, or feathers.  See Who is at a Higher Risk of Contracting H5N1? (below)
  • Pasteurized milk and dairy products are safe to consume, as the pasteurization process neutralizes the bird flu virus
  • Avoid contact with infected animals: People should avoid direct contact with wild birds and other animals infected with or suspected to have bird flu. Wild birds can be infected with bird flu even if they don't look sick.
  • Wear personal protective equipment (PPE) if you must work with infected animals: If you work with infected animals and must have direct/close contact, wear recommended PPE, such as: respirators (N95 masks), eye protection (face shields or safety goggles) and gloves.  
  • Get the seasonal flu vaccine: The California Department of Public Health recommends that all Californians — especially workers at risk for exposure to bird flu — receive a seasonal flu vaccine. Although the seasonal flu vaccine will not protect against bird flu, it can decrease the risk of being infected with both viruses at the same time and reduce the chance of severe illness from seasonal flu.
  • ​​Only consume pasteurized dairy products: Do not touch or consume raw milk or raw milk products. Pasteurized milk and dairy foods are safe to eat.  

You are at higher risk if you work with or are around poultry, dairy cows, alpacas, wildlife or raw (unpasteurized) milk.

Examples are:

Farmworkers Who:
  • Work with dairy cows 
  • Work with poultry
  • Handle raw dairy products 
  • Work in slaughterhouses 
Wildlife Workers Who Are:
  • Wildlife rehabilitation center staff and volunteers 
  • Veterinary clinic staff 
  • Pest management and animal removal personnel
  • Animal control officers and shelter staff 
  • Zoo staff and volunteers 

CDFA:  Avian Flu Updates 

CDPH: Worker Protection from Bird Flu

Influenza Aviar (en Español)

People infected with Bird Flu can have one or more of the following symptoms:

  • Cough
  • Diarrhea
  • Eye redness (conjunctivitis)
  • Fatigue 
  • Fever
  • Headaches
  • Muscle or body aches
  • Runny/stuffy nose
  • Sore throat
  • Trouble breathing
  • Vomiting