AVIAN INFLUENZA - ROUTES OF TRANSMISSION

What are the possible routes of transmission of avian influenza?

There are two possible ways in which the virus can be transmitted: the natural environment, and people.

How is the virus spread through the natural environment?

The virus can be spread by wild birds or by water. Waterfowl and shorebirds are prone to the virus, and there is incidence of low pathogenic avian influenza in wild birds tested by the CFIA.

Poultry feed may sometimes be exposed to droppings from wild birds. This risk might explain the outbreak in individual farms, but would not explain the rapid spread of the virus.

There is also a danger that wild birds may contaminate surface water, which might find its way to well water. This may be a risk for individual farms, but it is not likely the cause of the rapid spread of the virus among farms.

How is the virus spread by people?

There is a very broad range of people who come in contact with the avian influenza virus and could spread it if they do not take adequate biosecurity precautions. Owners and managers of multiple farms and farm workers who are employed on several farms must be very careful about following the biosecurity protocols. Feed representatives, poultry veterinarians, catching crews, spray crews and others having access to poultry premises could transmit the virus on their boots, clothing, or on the tires of their vehicles. Casual visitors and relatives provide a threat of transmission as well. Equipment used by any person visiting a poultry farm also provides a vector for transmitting the virus.

How can people prevent spreading or introducing the virus to poultry?

Basic biosecurity procedures can slow down the spread of the virus, helping the CFIA to contain and stamp out the virus. Strict on-farm and personal biosecurity practices protect poultry operations of any size.

• Keep poultry in closed poultry houses
• Keep wild birds and their feces away from poultry and poultry feed
• Seal poultry house attics and cover ventilation openings with screens
• Thoroughly and routinely clean all equipment, vehicles, including service vehicles, clothing and footwear before and after coming into contact with poultry
• Ensure proper hygiene practices for all persons coming into contact with poultry
• Maintain high sanitation standards in and around poultry houses
• Isolate or avoid introducing new birds into existing poultry flocks if their health status is unknown
• Limit access to poultry houses, including farm workers, feed suppliers, poultry veterinarians, catching crews, sawdust and shavings suppliers, agricultural service personnel and casual visitors
• Avoid using water in poultry houses contaminated with feces from wild birds
• Ensure thorough cleaning and disinfection for all cages transporting birds
• Maintain a log of all visitors coming into contact with poultry

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