Avian (Bird) Flu

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What is avian (bird) flu?

Avian influenza, (influenza A (H5N1)), also called bird flu, is a very lethal virus that occurs mainly in birds. Although avian influenza viruses do not usually infect humans, several instances of human infections and outbreaks have been reported since 1997. Avian influenza A (H5N1) is of particular concern because:

• The virus mutates rapidly
• It can cause severe disease in humans
• Is likely to acquire genes from viruses infecting other species
• The continued spread of infection in birds increases the opportunities for direct infection of humans

What are the symptoms of avian flu?

The symptoms are similar to typical influenza: fever, cough, sore throat, runny nose, and muscle aches. These symptoms can lead to more serious symptoms, such as eye infections (conjunctivitis), pneumonia, acute respiratory distress, and other life-threatening complications.

How is it spread?

It is spread by touching infected birds or coming into contact with their faeces. The disease can be spread through contaminated surfaces, such as equipment, vehicles and feed to other farms or poultry markets. 

Can it spread to humans?

Although rare, the H5N1 strain has spread from birds to humans. Exactly how humans become infected from birds is not known. Research has shown that the risk of spreading the infection from birds to humans is greatest in persons having close contact with live, infected poultry or contaminated surfaces. This includes high-risk exposure during the slaughter, defeathering and preparation, handling, and cooking of poultry. Since 1997 human infections with avian influenza viruses have not resulted in sustained human-to-human transmission. Scientists worry that the disease may merge with normal human influenza viruses to form a new strain of virus that allows spread between humans. This would be severe because humans would have little, if any, immunity.

What is the history of human illness?

• 1997: First cases of human infection in Hong Kong; six people died
• 1999: Hong Kong, two cases
• 2003: Hong Kong, two deaths; Netherlands (different strain), one death
• 2004: Vietnam, Cambodia and Thailand; ongoing with increasing illness and death

Is there a vaccine?

There is no vaccine currently available to protect humans against disease caused by H5N1 strain. Researchers are currently working to develop a vaccine. 

How is it treated?

Four different influenza antiviral drugs (amantadine, rimantadine, oseltamivir and zanamivir) are approved for the treatment and/or prophylaxis of influenza. All four have activity against influenza viruses; however, sometimes influenza strains can become resistant to these drugs causing them to be ineffective. Monitoring of avian viruses for resistance to influenza antiviral medications is ongoing by the World Health Organization.

How can I protect myself?

• The best way to protect yourself is to get the flu shot every fall. There is strong evidence to show that the vaccine prepares and boosts your immune system.   
• Stay away from people sick with the flu. After the onset of symptoms, the flu is contagious for 3-5 days in adults and up to 7 days in children.
• Wash your hands frequently with soap and water to prevent acquiring or spreading the virus.
• Travellers to Asia and other affected countries are advised to avoid contact with live poultry, such as at markets where live chickens, ducks and pigs are sold.
• Travellers are also advised not to bring poultry and egg products from affected countries into Canada.
• If you are traveling to an affected country consult the Public Health Agency of Canada travel health advisories at www.phac-aspc.gc.ca/tmp-pmv/.
• You may also contact Public Health for travel information.

Where can I find out more?

World Health Organization:

www.who.int/mediacentre/factsheets/avian_influenza/en/

World Health Organization:

www.who.int/foodsafety/micro/avian/en/

Public Health Agency of Canada:

www.phac-aspc.gc.ca/influenza/avian_e.html

Public Health Agency of Canada travel medicine program:

www.phac-aspc.gc.ca/tmp-pmv/

Ministry of Health and Long Term Care: www.health.gov.on.ca/english/public/program/emu/avian/avian_mn/html    and

http://www.healthyontario.com/english/condition_detail.asp?channel_id=5&disease_id=301

For more information please call Public Health at 519-376-9420 or 1-800-263-3456.

Source:

WHO

CDC

PHAC

MOHLTC

BC Health Guide