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Avian Influenza

Situation Update

As of October 24, 2022

Highly pathogenic avian influenza (HPAI) Eurasian strain H5N1 has been moving through bird populations across the county and more recently the state of California.  In late September 2022, Orange County had its first wild bird testing positive for HPAI H5N1.

  • HPAI H5N1 can infect and cause high mortality in both wild and domestic birds, including backyard and commercial flocks.
  • Risk of transmission of HPAI H5N1 to humans is considered low at this time.
  • The general public should avoid contact with sick or dead wild birds.
  • Individuals that have exposures to birds should wear personal protective equipment (PPE) including a mask, eye protection, gloves, and dedicated footwear and clothing when handling birds.
  • To report sick or dead birds in Orange County:


Avian influenza viruses occur naturally among wild aquatic birds worldwide and can infect other animals, including poultry. Infected birds shed avian influenza virus in their saliva, mucous and feces. Avian (bird) influenza A viruses do not normally infect people, but some human infections have occurred, usually after contact with infected animals or surfaces contaminated with their secretions or excretions. Illness in people has ranged from mild to severe and symptomatology is similar to that of human seasonal influenza except that diarrhea and conjunctivitis may be more prominent with some strains. Three subtypes of avian influenza A viruses are known to infect people (H5, H7 and H9 viruses). Among these, Asian lineage H5N1 and H7N9 have caused the majority of infections in people.

The spread of avian influenza A viruses from one ill person to another has been reported very rarely and has been limited in transmission and not sustained. However, because of the possibility that the avian viruses could change and be able to spread easily between people (and thus potentially cause a pandemic), monitoring for human infection with these viruses is critical.

Avian influenza is immediately reportable in Orange County, even if the case has not yet been confirmed but is suspected. To report a case, health care providers/facilities should call OCHCA Communicable Disease Control at 714-834-8180.
Human cases of avian influenza have not been reported in Orange County previously. 

Healthcare Professionals


Last Updated: 10/24/2022