Avian Influenza Information for Health Professionals

Avian influenza is a contagious viral infection that mainly affects birds. On occasion, avian influenza can infect humans and other mammals.  

Avian influenza (AI) A (H5N1) is an influenza virus that primarily infects domestic poultry and wild birds; however, mammals can also be infected with H5N1. Mammals can become infected with the virus when they eat infected birds, poultry, or other animals and/or if they are exposed to environments contaminated with virus. In infected poultry flocks, the influenza virus is shed through respiratory secretions of infected birds and fecal contamination.  

Avian influenza viruses usually do not infect humans and do not spread easily from person-to-person. Rare cases have been reported, most often in people who had close unprotected contact with infected poultry, cattle, or environments heavily contaminated with the virus. Precautions need to be taken by individuals who have exposures.

Avian influenza symptoms may appear within one to 14 days after exposure and can range from very mild to severe, including:

  • fever
  • cough
  • sore throat
  • runny or stuffy nose
  • muscle or body aches
  • headaches
  • fatigue or tiredness
  • conjunctivitis (red eyes)
  • shortness of breath or difficulty breathing

For the most up to date lab testing information please visit the Public Health Ontario (PHO) Avian Influenza – Real-time PCR webpage.

Prior to specimen submission for avian influenza testing, contact PHO’s Laboratory Customer Service Centre at 416-235-6556 (1-877-604-4567) for further instructions and testing approval. If it’s after-hours, contact the Emergency Duty Officer at 416-605-3113. Weekend testing is available and must be approved by a PHO microbiologist or designate.

In June 2025, Health Canada approved the Arepanrix™ H5N1 vaccine for individuals who face ongoing occupational exposure to the virus.

Ontario’s Human Vaccines Against Avian Influenza (HVAI) Program

TPH is participating in Ontario’s HVAI Program. This program outlines eligibility criteria for receiving the Arepanrix™ H5N1 vaccine, which is intended to protect individuals at higher risk of exposure to avian influenza A(H5N1). Eligible populations may change over time if the context and risk changes in Ontario.

Accessing the Arepanrix™ H5N1 Vaccine in Toronto

  • TPH has contacted settings in Toronto where eligible individuals work to help facilitate administration of the vaccine.
  • If an eligible patient has not been contacted, please contact, or have the patient contact, TPH at 416-338-7600 or PublicHealth@toronto.ca.

Antiviral medications may be considered after exposure to mammals or humans infected with avian influenza, as antivirals may help reduce the risk of symptomatic avian influenza infection.

  • Public health unit staff will identify and assess people who have been exposed and determine if prophylaxis should be recommended.

More Information:

 

Antiviral agents can be used to treat individuals with suspected or confirmed avian influenza A(H5N1).

  • The ideal time to begin antiviral treatment is within the first 48 hours of illness.
  • Treatment can be initiated while awaiting confirmatory test results and should not be delayed.

More Information:

  • A patient with suspected or confirmed avian influenza should be placed in airborne, droplet and contact precautions, ideally in an airborne infection isolation room (AIIR).
  • If an AIIR is not available:
    • Place the patient in a single, enclosed room with a dedicated toilet and hand hygiene facilities designated for their use
    • Keep the door closed
    • Portable HEPA filters may be considered by IPC and facilities personnel to supplement existing ventilation strategies
  • When caring for a patient with suspected of confirmed avian influenza, the following personal protective equipment (PPE) is recommended:
    • A fit-tested, seal-checked N95 (or an equivalent or higher protection) respirator
    • Eye protection (i.e., goggles or face shield)
    • Gown
    • Gloves
  • If tolerated, the patient should wear a medical mask while healthcare providers are providing patient-facing care and when the patient is outside of their room or care area. Patients should clean their hands before or after touching their mask.

      More Information

      Immediately report all suspect or confirmed cases of avian influenza to TPH at 416-392-7411 during regular business hours (8:30 a.m. to 4:30 p.m., Monday to Friday) or after-hours by calling 311 (or 416-392-2489 if calling from outside of Toronto).