Highly Pathogenic Avian Influenza (HPAI)

Highly pathogenic avian influenza (HPAI) also known as HPAI A(H5N1) virus otherwise known as bird flu:

  • Is caused by influenza type A viruses.
  • Occurs naturally in wild aquatic birds. It can also infect domestic birds such as, chickens, turkeys, and geese.
  • Has also infected wild and domestic mammals such as, bears, seals, raccoons, dairy cattle, goats, and cats. See HPAI Detections in Mammals for updated information.
  • Spreads easily among bird and has caused severe disease in birds. It rarely infects people.
  • When it does infect people, the effects may range from mild illness to severe disease and death. See Bird Flu Virus Infections in Humans | Avian Influenza (Flu) for signs and symptoms
  • Animals shed HPAI in their saliva, mucus, and feces. HPAI has also been found in raw (unpasteurized) milk.
  • People can become infected when infectious material comes in contact with a person’s eyes, nose, or mouth. People may also inhale the virus particles.
  • HPAI rarely spreads from one person to another.
  • Take precautions around sick animals and protect workers from exposure.

Highly pathogenic avian influenza (HPAI) virus is caused by certain avian influenza Type A viruses. These viruses occur naturally in wild birds. HPAI virus has also infected domestic birds, such as chicken and turkeys. In birds, it spreads easily. It frequently leads to death. HPAI virus can also infect wild and domestic mammals such as foxes, bears, seals, sea lions, cats, dogs, mink, goats, and cows. See HPAI Detections in Mammals (usda.gov) for updated information.

To date, HPAI virus has rarely infected people. When it does infect people, it very rarely spreads from person-to-person. People with extended close contact to someone with HPAI virus, for example healthcare workers or household members, are most likely to get HPAI from another person. HPAI in people can result in asymptomatic or mild disease. In some countries, it has more commonly lead to severe disease and death. See Bird Flu Virus Infections in Humans | Avian Influenza (Flu) (cdc.gov) for signs and symptoms. Employers should implement controls to protect workers from exposure to HPAI virus.

Getting Started


Sick animals shed avian influenza virus via bodily fluids including:

  • Saliva and respiratory secretions
  • Feces
  • Raw (unpasteurized milk)

Dead animals and their bodily substances may be infectious.

People can have exposure to HPAI through:

  • Inhalation of infectious airborne or aerosolized particles
  • Direct contact with mucus membranes of the eyes, nose, or mouth, for example splashes or sprays of contaminated substances to the face
  • Indirect contact with mucus membranes of the eyes, nose, or mouth, for example touching contaminated surfaces then touching eyes, nose, or mouth without washing their hands.

Workers at Risk

  • Workers who have contact with dead or sick animals including:
    • Wild birds or their waste
    • Domestic livestock (like cattle or goats) or their waste
    • Wild mammals or their waste

Note: See HPAI Detections in Mammals (usda.gov) for updated information.

  • Workers who have contact with unpasteurized “raw” milk, especially, if there is potential for aerosolization
  • Workers involved with animal and food processing including slaughter and dairy products
  • Workers that work with, care for or handle animals like:
    • Farm workers interacting with poultry, cattle, sheep and goats
    • Animal Control Officers
    • Wildlife Officers
    • Wildlife and domestic animal researchers
    • Park workers
    • Pet trade
    • Veterinarians and technicians
    • Zookeepers and animal caretakers
    • Maintenance workers working on animal housing facilities
  • Workers working outdoors doing maintenance, construction, remodeling, landscaping, who may contact birds and other animals including their waste, saliva or respiratory secretions
  • Workers that have close contact with someone with HPAI like Healthcare workers and caregivers.


Employers must protect workers from serious hazards in the workplace according to WAC 296-800-110, Employer responsibilities: Safe workplace, Chapter 296-155 WAC, Safety Standards for Construction and Chapter 296-307, WAC Safety Standards for Agriculture, including some infectious diseases that may be acquired in the workplace. Unprotected contact with animals or people with HPAI poses a significant risk to workers. Employers must assess avian influenza hazards in the workplace and implement effective controls to protect workers. Healthcare workers should follow CDC’s transmission-based precautions and guidance for HPAI. Determine the exposure controls to implement by the specific work task, setting, and exposure such as:

  • Including HPAI exposure hazards in your accident prevention plan (APP).
  • Avoiding unprotected contact with animals or people with known or suspected HPAI when possible.
  • Maintaining distance from items with known or suspected to have contamination with HPAI.
  • Maintaining distance from items with known or substances known or suspected to be contaminated with HPAI.
  • Using tools (such as tongs) to avoid direct contact and maintain distance from substances known or suspected to be contaminated with HPAI.
  • Using processes to avoid aerosolization known or suspected contamination of HPAI. If aerosolization is unavoidable, implement additional precautions, such as enhanced ventilation (like local exhaust ventilation and no recirculation of the air) and use of respirators.
  • Avoiding stirring up waste and other potentially contaminated dirt or dust.
  • Ensuring optimal ventilation (for examples stay up wind from the hazard, ventilate with as much fresh air as possible with no recirculation of the air).
  • Ensuring adequate access to hand washing facilities. Use alcohol based hand sanitizer when soap and water is unavailable and hands are not visibly dirty
  • Washing hands with soap and water:
    • After contact with animals or people with known or suspected HPAI
    • After contact with substances or objects known or suspected to be contaminated with HPAI
    • When leaving a potentially contaminated area
    • After removing gloves and other PPE
    • Before touching your face (especially eyes, nose, or mouth), eating, drinking, smoking, chewing tobacco, taking medication or applying cosmetics
  • Cleaning surfaces and disinfect using an EPA registered product effective against HPAI. Protect workers from chemical hazards from these products by implementing appropriate safety precautions.
  • Ensuring employees have been educated and trained in a language and manner that they understand on the HPAI hazards in the workplace and policies and procedures to prevent transmission.
  • Following state agency (for example DOH, WSDA, WDFW) recommendations for symptom monitoring and testing.
  • Completing a hazard assessment and using personal protective equipment (PPE) when in close or direct contact with animals or people with known or suspected HPAI is unavoidable.
    • Using a NIOSH approved respirator like an N95
    • Disposable exam weight gloves
    • Disposable fluid-resistant coveralls
    • Unvented or indirectly vented safety goggles
    • Disposable head cover or hair cover

NOTE: Before using respirators make sure you have and follow your written Respiratory Protection Program including requirements for selection, medical evaluations, fit-testing, training, maintenance and storage of respirators. See Chapter 296-842 WAC – Safety Standards for Respirators.

Reporting and Recording

Record and report workplace related HPAI according to Chapter 296-27 WAC – Recordkeeping and Reporting. HPAI does not fall under the exclusion for “common cold and flu” in WAC 296-27-01103 (2)(h). See L&I’s Workplace Injuries & Fatalities webpage for more information.

Other reporting:

  • Cases, suspected cases, or exposure in people report to your local health jurisdiction
  • Sick or dead birds in domestic birds report to the Washington State Department of Agriculture, Avian Health program: 1-800-606-3056
  • Increased death or disease in livestock on farms to the State Veterinarian on the Reportable Animal Disease Database and select “unexplained increase in dead or diseased animals”.
Requirements & Policies

Employers are required to provide a workplace free from recognized hazards, including biological agents. Protections may include the use of personal protective equipment (PPE) and respirators. L&I does not have rules that specify specific controls to mitigate HPAI, including the circumstances under which workers must use respirators. However, L&I requires employers to evaluate hazards in the workplace and expects that workplace develop their controls, including respiratory protection policies, based on public health guidance from CDC, state, and local health departments. Depending on the specific work task, setting, and exposure, some L&I standards that may apply include:


Standards and Guidance from others

Training & Resources

Meeting Workplace Safety & Health Requirements

You can use these materials to meet specific requirements in L&I Safety & Health rules. You can use other materials as well.

Training & Resources

Publications, Handouts, Checklists

Sample Programs

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