Avian influenza A(H5N1): Spread, prevention and risks

Current situation

Outbreaks of avian influenza A(H5N1) continue to occur in Canada and globally. The risk of avian influenza infection to most people in Canada remains low.

• Latest bird flu situation
• Avian influenza A(H5N1): Canada's response

Avian influenza A(H5N1) is also known as bird flu or avian flu. It's a contagious viral infection that mainly affects birds, but can sometimes infect other animals and humans.

On this page

• How A(H5N1) spreads
• Preventing A(H5N1)
• Risks of getting A(H5N1)
• Who is most at risk
• What to do if you've been exposed
• Recommendations for travellers

How A(H5N1) spreads

A(H5N1) is commonly found in birds in many areas around the world. Although it spreads easily between birds, it doesn't spread as easily to other animals or people.

A(H5N1) can spread in the following ways.

Bird to bird

A(H5N1) can infect many species of birds including:

• wild birds, such as:
  • waterfowl like ducks and geese
  • birds of prey and scavengers like eagles, hawks and crows
  • shorebirds and seabirds like gulls and terns
• domestic poultry and other farmed birds like chickens and turkeys
• pet birds

A(H5N1) can spread from an infected bird to another through their:

• feces
• feathers, bedding or litter
• mucus, saliva or other secretions

Certain types of wild birds are natural carriers of avian influenza viruses. While some may get sick and die, others can be infected and still appear healthy.

Domestic poultry (like chickens and turkeys), other farmed birds and pet birds are more likely to become severely ill and die.

Learn more:

• Avian influenza in wild birds
• How to prevent and detect disease in small flocks and pet birds
• Avian biosecurity: Protect poultry, prevent disease (for producers, service industry, pet bird and flock owners)

Bird to mammal

While A(H5N1) is mainly a bird disease, it can also infect mammals, especially those that:

• hunt, scavenge or eat infected birds
• are exposed to contaminated environments like animal farms or live animal markets

Examples of mammals that have been infected include:

• wild mammals like foxes, skunks and raccoons
• cats and dogs
• livestock like cattle, alpacas and goats
• marine mammals like seals, dolphins and sea lions
• animals farmed for fur like mink

Learn more:

• Highly pathogenic avian influenza in livestock
• Animals susceptible to A(H5N1) highly pathogenic avian influenza

Mammal to mammal

There have been increasing reports of A(H5N1) spreading between mammals. This includes situations involving:

• dairy cattle
• farmed fur animals
• marine mammals

The exact way it's spreading within these groups isn't yet known but may involve:

• exposure to:
  • infected animal products like raw (unpasteurized) milk
  • infectious respiratory particles and secretions
  • contaminated environments and farm equipment
• movement of animals and people who work with animals between locations

Animal to human

A(H5N1) is rare in humans. Spread is possible through close contact with:

• infected birds, especially poultry, or other infected animals like dairy cattle
• highly contaminated environments like animal farms or live animal markets
• higher-risk environments like backyard or small poultry flocks and hobby farms

You can become infected with A(H5N1) if the virus from an infected animal gets into your mouth, nose or eyes. For example:

• breathing the virus in through particles in the air or dust
• direct contact (through eyes, nose or mouth) with infectious particles or contaminated material like raw milk or feathers
• touching your eyes, nose or mouth after touching something (such as a surface or object) that has the virus on it

There hasn't been a documented case of a person getting A(H5N1) from a household pet or wild mammal, but it's potentially possible. Cats and dogs that go outdoors may hunt and eat infected wildlife. If you have animals, take precautions to protect them and yourself.

Based on current evidence, A(H5N1) doesn't spread through:

• fully cooked poultry, beef, game meat, organs or eggs
• pasteurized milk or pasteurized milk products

Learn more:

• Raw or unpasteurized milk
• Safe cooking temperatures
• Highly pathogenic avian influenza and food safety
• Avian influenza A(H5N1): Handling potentially infected animals
• Animals susceptible to H5N1 highly pathogenic avian influenza (HPAI)

Human to human

Although A(H5N1) spreads easily between birds, it doesn't spread easily between people.

There have been some reports of possible limited human-to-human spread in other parts of the world. There's no evidence of ongoing spread between people.

Learn more:

• How respiratory infectious diseases spread

Human to animal

It's potentially possible for people infected with A(H5N1) to spread the virus to animals, such as cats, through close contact. If you have A(H5N1), take precautions to avoid spreading the virus.

Learn more:

• Preventing A(H5N1)

Contaminated environments, surfaces or objects

Highly contaminated environments, like animal farms and live animal markets, pose a higher risk of A(H5N1).

The majority of human cases of A(H5N1) have occurred after contact with infected birds. However, some people have been infected after being exposed to:

• highly contaminated environments like animal farms and live animal markets
• higher-risk environments like backyard or small poultry flocks and hobby farms

It's possible to get an infection from:

• breathing the virus in through particles in the air or dust
• direct contact (through eyes, nose or mouth) with infectious particles or contaminated material like raw milk or feathers
• touching a contaminated surface or object, and then touching your eyes, nose or mouth before cleaning your hands

Learn more:

• Survival time of avian influenza virus

Preventing A(H5N1)

Preventing animal to human spread

• Do not touch, feed or handle potentially infected birds or other animals, including wildlife and livestock, especially if they seem sick or are dead.
  • If you must have contact, wear:
    • gloves
    • a well-fitted respirator or medical mask
• Wash your hands after touching animals or animal products, or after being in a higher-risk area like a park, zoo, farm, fair or animal market.
  • When possible, use soap and water to wash your hands, especially if they look dirty.
    • If soap and water aren't available, use a hand sanitizer containing at least 60% alcohol.
• Thoroughly cook poultry, meat, organs, eggs and other food products containing these ingredients, as this will kill avian influenza viruses.
  • Do not feed your pets diets, treats or other products made with raw meat, organs or eggs.
• Do not consume raw milk and milk products.
• Milk must be pasteurized in order to be sold legally in Canada.
• Drinking raw milk is risky because it may contain harmful pathogens.
• Do not feed your pets raw milk or milk products.
• Keep pets away from potentially infected birds and other animals, their feces and their enclosures.

If you find a sick or dead animal that may have A(H5N1), keep your distance and do not touch it. Report it to the appropriate animal health authority.

Report sick or dead animals: Handling potentially infected animals

Learn more:

• Food safety: Pet food and treats
• Highly pathogenic avian influenza and food safety
• Avian influenza in wild birds: Reporting sick or dead birds
• Avian influenza A(H5N1): Handling potentially infected animals
• Respiratory infectious diseases: Mask use for reducing the spread
• Clean your hands to help reduce the spread of infectious diseases

Preventing human to human spread

To help prevent spreading A(H5N1) to others, use personal protective measures when you're sick or if you may have an infection.

• Stay home and avoid sharing indoor and outdoor spaces with other people and animals.
• Wear a well-fitted respirator or medical mask.
  • This is especially important around individuals who are at risk of more severe diseases or outcomes, including those who are:
    • immunocompromised
    • pregnant
    • young children
• Avoid sharing personal items, including unwashed towels, bed linen and eating utensils with other people and animals.
• Improve indoor ventilation by opening a window or door, especially in shared spaces.
• Clean your hands often with soap and water for at least 20 seconds or use hand sanitizer containing at least 60% alcohol.
• Cover your coughs and sneezes with a tissue or the bend of your arm.
• Clean and disinfect high-touch surfaces and objects frequently, including:
  • taps
  • toilets
  • kitchen countertops
• Wash clothes and bed linen with regular laundry soap and water.

Learn more:

• Survival time of avian influenza virus on surfaces
• Respiratory infectious diseases: What personal protective measures to use

Preventing human to animal spread

To prevent spreading the infection, anyone with suspected or confirmed A(H5N1) should avoid contact with birds and other animals.

Learn more:

• Tips to protect your pet bird
• Tips to protect your mammalian pets

Vaccines

The Public Health Agency of Canada has purchased 870,000 doses of human vaccine against avian influenza. The vaccine is intended to proactively protect individuals with an increased risk of exposure to the virus. If necessary, the vaccine can be used for a public health response based on risk conditions.

This is particularly important for people who may have significant exposure to A(H5N1) through their work, such as:

• poultry or livestock farmers and agricultural workers
• slaughterhouse and processing plant workers
• wildlife officers and researchers
• wildlife rehabilitators
• veterinarians and veterinary staff

In addition, almost everyone 6 months of age and older should get their seasonal flu vaccine each year. While it won't protect you from A(H5N1), it will help prevent severe infection from seasonal flu.

Learn more:

• Get your flu vaccine
• Avian influenza A(H5N1): Canada's response

Risks of getting A(H5N1)

A(H5N1) is rare in humans. The risk of infection for the general public is low.

Over 900 human cases of A(H5N1) have been reported around the world since 1997. Most of these cases have been in Africa and Asia. Because some people can have mild symptoms or no symptoms at all, it's hard to know exactly how many people have been infected. These cases often go undetected and aren't reported.

Learn more:

• Human emerging respiratory pathogen bulletin (technical data)

Who is most at risk

You're most at risk of getting A(H5N1) if you:

• work with or handle potentially infected wildlife and domestic animals (like farmed animals or pets)
• work in highly contaminated environments

Activities that may increase your risk of exposure and infection include:

• working with or handling wild or domestic animals that might be infected
• working in environments that are heavily contaminated with:
  • feathers
  • animal feces or litter
  • raw milk
  • other secretions from infected animals
• visiting animal farms or live animal markets
• having close contact with someone who has or may have A(H5N1), such as living, working or playing in the same space or touching their personal items
• handling or consuming raw or undercooked poultry, meat, organs or eggs, or drinking raw milk or consuming raw milk products

If you work with or handle animals, or work in a potentially contaminated environment, it's important to take precautions to avoid getting A(H5N1).

Learn more:

• Animal-related diseases: Resources for workplaces
• Staying healthy when working with or near wildlife (poster)
• Avian influenza A(H5N1): Handling potentially infected animals

What to do if you've been exposed

If you think you may have been exposed to A(H5N1):

• self-monitor for symptoms for 10 days after your last exposure and
• contact your local public health authority for further guidance

If symptoms develop, contact your health care provider immediately for assessment and recommendations.

Use personal protective measures to prevent the spread of A(H5N1) to others.

Learn more:

• A(H5N1): Symptoms and treatment
• Respiratory infectious diseases: What personal protective measures to use

Recommendations for travellers

Talk to a health care provider or visit a travel health clinic preferably 6 weeks before your trip to get personalized health advice. Even if your travel date is coming up soon, it's still worthwhile to make an appointment.

Before travelling, check the travel advice and advisories page for your destination. Information on health risks, like avian influenza, can be found in the 'Health' section.

Travel advice and advisories

While travelling, continue to take steps to prevent the spread of illness by:

• avoiding contact with animals and high-risk activities during your trip
• using personal protective measures like washing your hands often and covering your coughs and sneezes with a tissue or the bend of your arm

If you develop flu-like symptoms while travelling from an area where avian influenza is a concern, tell a border services officer upon your arrival. If symptoms develop after your return, contact a health care provider immediately. Tell them about your symptoms and where you've been travelling or living, and follow their instructions.

Learn more:

• Travel health notices
• Plan for your health before and during travel
• If you become sick or injured while travelling outside Canada or after your return
• Respiratory infectious diseases: How to reduce the spread with personal protective measures