Animals > Animal Diseases > Avian Influenza  

Overview of Avian Influenza Prevention, Preparedness and Response

Executive Summary | Prevention and Early Warning | Emergency Preparedness | Communications | Response | Conclusions

Executive Summary

Avian influenza (AI) is a contagious viral infection that can affect several species of poultry, such as chicken and turkey, as well as pet and wild birds. AI viruses can be classified into two categories-low pathogenic (LPAI) and high pathogenic (HPAI)-based on the severity of the illness caused in poultry. HPAI viruses cause severe illness and mortality, whereas LPAI viruses typically cause little or no clinical signs. Most AI viruses are low pathogenic; however, some are capable of becoming highly pathogenic. Historically, only the H5 and H7 LPAI virus subtypes are known to have the ability to become highly pathogenic.

AI is not new. As a poultry disease, it has been recognized since the beginning of the last century, and AI viruses have long been present in wild birds. In 1997, a high pathogenic strain of H5N1 AI emerged in South-East Asia. This particular virus, which is marked by rapid illness and high mortality in infected birds, has since spread throughout numerous Asian, Middle Eastern, African, and European countries. It has also been associated with illness and death in humans that have had close contact with infected birds. Public health authorities around the world are concerned about the potential for a human-adapted strain of this virus to arise, resulting in human-to-human transmission and a human influenza pandemic.

Since 2004, Canada has faced two outbreaks of AI in domestic poultry, but the Asian H5N1 virus has yet to be detected in this part of the world. However, the movement of AI viruses is not restricted by borders. Because AI viruses may be carried by migratory birds and the global movement of potentially contaminated products, it is important that Canada stand prepared should we face other outbreaks of AI, including Asian H5N1.

The Government of Canada attaches high priority to the threat of AI and is devoting significant resources to prevent the introduction and spread of AI in Canada. The Canadian Food Inspection Agency (CFIA) is at the forefront of that effort.

The CFIA, working with a number of Government of Canada partners, has put in place a series of measures to limit the animal health risks-and associated economic repercussions of outbreaks-posed by AI. In the context of human health, these measures also reduce the potential risk that AI infection in birds will serve as the precursor to a human flu pandemic. International human and animal health authorities agree that efforts to protect human health are best directed at preventing, limiting and eradicating AI outbreaks in domestic poultry.

The Canadian Food Inspection Agency’s AI measures fall within four specific areas:

1. Prevention and Early Warning
2. Preparedness
3. Communications
4. Response

Prevention and Early Warning

There are a wide range of AI viruses continuously circulating within wild bird populations. The majority of these do not cause serious illness in animals or humans. The first lines of defence against an outbreak of AI in domestic poultry are prevention measures and early warning systems. The CFIA, in collaboration with other Government departments, has put in place safeguards to limit the introduction and spread of AI in Canada’s domestic poultry populations. These measures include:

• Surveillance
• Biosecurity
• Import Controls

Surveillance

The Canadian Government is implementing two different bird surveillance programs to detect AI viruses posing threats to domestic poultry at the earliest possible moment. The first program targets wild birds; the second one will focus on domestic flocks.

Wild Bird Surveillance

The CFIA, Environment Canada, The Public Health Agency of Canada and the Canadian Cooperative Wildlife Health Centre are collaborating to conduct the second annual survey of AI viruses in wild birds. As was the case in 2005, the survey partners expect to find a variety of AI viruses, most of which commonly circulate in wild birds with little or no impact on their health or the health of other animals. The 2006 survey, which will be carried out through the spring, summer and fall, will enable animal and public health authorities to better understand the presence and characteristics of typical strains of AI in North America's wild bird population.

Survey partners are particularly interested in AI viruses that are or have the potential to become highly pathogenic. These viruses, which include the H5 and H7 subtypes, can cause illness and death in poultry. The highly pathogenic H5N1 AI virus strain currently circulating in Asia, Africa and Europe has demonstrated the ability to affect poultry and wild birds, as well as humans and other mammalian species.

Canada is monitoring global AI developments very closely, particularly the spread of the Asian H5N1 strain. Recognizing that better understanding of viruses and their exchange, as well as early detection, represent Canada's first line of defence in protecting animal and human health, the 2006 survey was identified as a priority in the 2006 Federal Budget and will incorporate a number of enhancements.

Similar to the 2005 survey, this year's survey will sample migratory birds along main migratory routes in Canada; however, it will place a greater focus in the north Atlantic region, which hosts birds that might come into contact with birds from Europe where the Asian H5N1 strain has been found in several countries. This component will include sampling in Iceland, which hosts migratory birds from both North America and Europe. Canada is coordinating its survey approach with the United States, which has announced plans to conduct extensive surveillance along the Pacific Flyway, which intersects with Asian migratory routes.

The 2006 Canadian survey will include expanded testing of dead birds. This portion of the survey will begin in Southern Canada in mid-summer; dead birds found prior to this would not have been exposed to potential sources of foreign avian influenza. As the collection period for dead birds nears, the Government of Canada will provide the public with information on how to proceed should a dead bird be found.

Survey results will be reported to Canadians as they are confirmed and will be available at the Canadian Cooperative Wildlife Health Centre Web site at http://wildlife1.usask.ca/.

Commercial Bird Surveillance

The CFIA, in collaboration with industry, is designing a commercial bird surveillance program similar in nature to the wild bird survey. Samples would be taken from live birds on farm and tested in CFIA accredited labs. This survey would help us develop a better picture of AI viruses that might be circulating in Canadian poultry and can help to identify where breaches of on-farm biosecurity might have occurred and identify courses of corrective action. Additionally, abnormal patterns of bird mortality would be watched closely.

International Bird Surveillance

In 2005, over 30 nations conducted bird surveillance programs. Through international cooperation and information sharing, Canada continuously monitors AI developments around the world and adjusts import controls and disease response plans accordingly.

Biosecurity

AI virus can be transmitted directly from bird to bird through secretions and feces, and indirectly through contaminated feed, water and equipment. In light of the threat and risks associated with AI, increased attention has been drawn to the ongoing need to protect domestic poultry through the effective use of on-farm biosecurity measures. Biosecurity involves maintaining good hygiene practices and limiting exposure to external sources of contamination.

Commercial Flocks

Most poultry and egg production industry associations already have biosecurity guidelines in place for their memberships to reference. The CFIA’s role involves promoting best practices and providing technical advice across industry so that all producers are using the most effective measures possible and that these measures are being applied in a uniform fashion across the country.

Other Flocks

The CFIA recognizes that not all poultry and egg production in Canada is done by large producers that are members of industry associations. There are smaller producers who maintain what are commonly called “backyard flocks.” The CFIA, in collaboration with the provinces and territories, is implementing an awareness campaign for owners of these types of flocks to inform them of biosecurity best practices and encourage them to take the necessary steps to protect their flocks.

Import Controls

On April 25, 2006, the CFIA announced enhanced control measures on imports of live birds from all countries eligible to export birds to Canada to further limit opportunities for the importation AI to Canada.

These measures apply to countries which are recognized as being free of highly pathogenic AI in their domestic flocks. Canada continues to prohibit trade in poultry, poultry products and birds with any country unless they are proven to be free of highly pathogenic AI in its domestic flock.

These measures are consistent with guidelines established by the World Organization for Animal Health (OIE) and provide a foundation for safe trade while protecting animal and human health. Canada’s import controls were developed in consultation with provincial governments, the Canadian poultry industry and Canada’s principal poultry and bird trading partners: the United States and the European Union.

The enhanced measures include new quarantine and inspection requirements for both the exporting country and the Canadian importer. Details of these measures are available on the CFIA website http://www.inspection.gc.ca/english/anima/heasan/disemala/avflu/imp/impbiroise.shtml

Emergency Preparedness

While it is extremely important to have early warning systems and prevention measures in place to keep AI out of Canada, similar effort must be directed toward being prepared for the possibility of an outbreak. Since 2004, Canada has had two AI outbreaks, during which many valuable lessons were learned and experience gained. The CFIA’s emergency preparedness approach focuses on five areas:

• Emergency response teams
• Development of detailed procedures for response
• AI scenarios and exercises
• Partnerships with other levels of government, other federal government departments and external bodies
• Surge capacity

Emergency Response Team

The CFIA has a dedicated response team of experts that will be activated in the event of an AI outbreak. This group includes veterinarians, executive management and field staff, will oversee the CFIA’s response and coordinate actions with federal, provincial and municipal partners.

Development of Detailed Procedures for Response

Preparedness requires that contingency plans be in place for every activity associated with an outbreak. Among the many detailed plans and procedures that are being developed, there are plans for: humane destruction of infected flocks rapidly, minimizing the spread of virus; effective disposal of carcasses; movement restrictions on susceptible livestock and products; protecting the health and safety of staff deployed during an AI outbreak, protecting the health of farmers and producers during an AI outbreak, and capturing information in databases for epidemiological analysis of the outbreak.

Avian Influenza scenarios and exercises

The CFIA conducts a number of internal and external exercises to further enhance preparedness for a possible AI outbreak. Internally, the CFIA continues to enhance its ability to respond through ongoing emergency preparedness workshops and training events. Externally, the CFIA participates in industry exercises to test response to AI in different parts of Canada. In 2006, the CFIA will complete a pandemic-focussed exercise with other government departments and other levels of government.

Partnerships with other Government Departments, other levels of Government and External Bodies

The CFIA continues to work closely with other Government departments, other levels of government, the poultry and egg producing industries and the scientific and academic communities, all of which have a focus on AI.

Partnerships with other Federal Government Departments and Agencies

At the Federal level, the CFIA’s AI partners include, but are not limited to, Agriculture and Agri-Food Canada, the Department of Foreign Affairs and International Trade, Environment Canada, Health Canada, the Public Health Agency of Canada, Public Safety and Emergency Preparedness Canada and the Canada Border Services Agency.

The lead department or agency in the event of an AI outbreak is scenario dependent. If the scenario only involves animal health, then the CFIA will have the lead and coordinating role in responding to the threat. If the scenario starts as an animal health issue, and then evolves into a human health issue, then the lead and coordinating role would shift to the Public Health Agency of Canada. In the event that AI starts as a human health issue, the Public Health Agency of Canada would assume the lead role in coordinating the response.

The CFIA collaborates with these partner departments on AI and pandemic scenarios on an on-going basis. The CFIA is also participating in a Public Safety and Emergency Preparedness Canada initiative to create an over arching Avian Influenza/Pandemic Strategy. In partnership with the Public Health Agency of Canada, the CFIA is assisting in the creation of an integrated Avian and Pandemic Influenza Response Plan.

The CFIA, in conjunction with the Canada Border Services Agency, is spearheading a Travellers Awareness Campaign. This campaign is targeted at all travellers entering Canada to inform them of all of the associated risks of bringing foreign materials into Canada that could be contaminated with AI virus and other threats. The CFIA took a leading role in this campaign, as undeclared imported items represent a clear threat to Canada’s livestock, as well as plants and natural habitats.

Provinces and Territories

The CFIA continues to communicate with its counterparts in the provinces and territories to ensure that information, policies, procedures, strategies, plans and communications products are shared and coordinated.

In April 2006, the CFIA compiled the existing risk analysis from all federal, provincial and territorial authorities. This data will be used to prioritize the scrutiny of potential entry points for the introduction of AI into Canada and develop a gap analysis to determine where resources should be focused to combat AI in Canada.

In June of 2006 the Federal, Provincial and Territorial Agriculture Ministers will attend a conference during which AI will be an agenda topic of major importance. Possible AI outbreak scenarios will be discussed. A draft national strategy and governance model on biosecurity and segregation will be shared. Policies around non-commercial flocks will also be finalized with our provincial and territorial partners.

The CFIA, in collaboration with provincial governments, is updating the joint Foreign Animal Disease Emergency Support Agreements, which define the roles and responsibilities of each partner in the case of a disease outbreak. These plans are based on four major disease control principles: rapid detection of newly infected livestock; halting the spread of the disease through movement controls and the rapid destruction of infected livestock; movement controls and surveillance on high risk livestock and proximal livestock; and preventing re-infection through the effective biocontainment of infective material (carcasses, manure and feed).

Industry and Academia

The CFIA has solicited expertise from industry and the scientific and academic communities by striking an Avian Influenza Advisory Group. Representatives are helping ensure that CFIA policies and action plans are sound. These consultations are ongoing and continue to provide valuable intelligence that helps to shape the CFIA’s overall strategy to combat AI in Canada.

Partnerships with International Bodies

The CFIA collaborates with leading international bodies such as the World Organization for Animal Health, the Food and Agriculture Organization and the World Health Organization to share and distribute intelligence, and best practices with regard to combating Avian Influenza. The fight against AI is truly an international effort with many nations, including Canada, providing assistance to other areas of the world where resources may be limited and are needed to help contain the global spread of AI. This effort benefits all nations and serves the best interests of Canada.

Additional Capacity

It is understood that responding to an AI outbreak will require additional human resources, equipment and facilities. The CFIA determines how much “surge capacity” will be needed to address a specific threat and then develops unique contingency plans to add resources and capacity as needed. This is especially true for AI. Surge capacity planning with regard to AI focuses on the following areas:

Internal Staffing Reserve - ensuring the CFIA has enough staff, back-up staff and staff rotation for the duration of an AI outbreak.

External Staffing Reserve - ensuring that the CFIA has identified, trained and accredited persons not currently on CFIA staff, but having relevant experience, so that they can be deployed during an AI outbreak, if required.

Equipment - ensuring that the CFIA can, at short notice, acquire and deploy the equipment required to address an outbreak of AI in Canada. This would include, but is not limited to, personal protective equipment for CFIA staff, vehicles, and depopulation equipment for the humane culling of infected livestock.

Laboratories - Six provincial laboratories have recently been CFIA approved for AI sample testing. The CFIA maintains four labs of its own so that it can also conduct AI testing. CFIA lab staff can be mobilized to move closer to an AI outbreak anywhere in Canada.

Communications

The CFIA recognizes that communication is a key component in Canada’s national effort to prevent, contain and eliminate AI outbreaks.

The CFIA maintains ongoing and frequent communications with federal and provincial government partners, the animal health community, bird owners, industry, international disease control authorities and, most importantly, the Canadian public. Timely and transparent communication ensures that the most reliable and recent information is available to decision makers, stakeholders and Canadians. The CFIA recognizes that awareness and credible, science-based information are essential components of Canada’s AI readiness and response capacity.

Response

In the event of an outbreak of AI in Canada, Canadians can be assured that the CFIA has action plans to guide effective and efficient response operations. These plans draw from previous experience in Canada and abroad, and the most current internationally accepted understanding of AI.

While specific response elements vary based on the virus and infected poultry species, the CFIA’s actions generally include movement restriction, disease containment and surveillance components.

Disease Containment

All infected flocks are humanely destroyed, and carcasses are disposed of in an environmentally acceptable fashion. Infected premises are thoroughly cleaned and disinfected before new birds can be introduced. Where highly pathogenic virus is present, flocks in the vicinity of infected premises and those from poultry operations that may have had contact with infected premises are also humanely destroyed and disposed of as a pre-emptive measure.

Surveillance, Quarantine and Segregation

Because each outbreak situation is unique, CFIA responses are flexible and may differ based on a variety of factors. For example, some disease response protocols are species specific. What follows, therefore, is the general approach to surveillance and segregation after an outbreak of AI in domestic poultry has been confirmed.

Quarantines restricting the movement of poultry and poultry products are placed on infected premises, poultry operations located in the vicinity of infected premises and other poultry operations that may have had contact with infected premises. Birds from quarantined premises are tested and monitored for evidence of AI infection

The CFIA may also ask domestic poultry producers to execute a segregation protocol. A segregation protocol seeks to minimize, if not eliminate, potential contact between wild birds and domestic or captive birds in the area after a case of HPAI has been confirmed.

During highly pathogenic avian influenza outbreaks a Control Area is established by Ministerial Order and two different zones around the infected area are created, a protection zone and a surveillance zone.

Protection Zone

The protection zone is established with a radius of 3 km from the infected farm and will last for a minimum of 21 days from the date the virus was identified. Birds within the zone will be sampled and tested. Strict biosecurity measures will be in force for all poultry farms in the zone, with access to the zone controlled and vehicles and things leaving subjected to cleaning and disinfection. All domestic birds should be confined within a facility erected and laid out in a manner that prevents any direct or indirect contact with wild birds. The public will be notified within the area to increase disease awareness amongst owners, hunters and bird watchers. Live poultry shows, displays or markets may not be conducted. Transportation of litter or manure out of the protection zone will be prohibited. There should also be a cessation on bird hunting activities within the zone.

Surveillance Zone

A surveillance zone is established with a radius of 10 km from the infected farm and will last for a minimum of 21 days from the date the virus is identified. Within the zone all domestic or captive bird flocks will be identified. Appropriate farm biosecurity measures will be required from flock owners in the zone. There will be controls on the movement of poultry and hatching eggs. Transportation of poultry and captive birds out of the surveillance zone will be prohibited a period of time following establishment of the zone. Bird hunting will be actively discouraged inside the zone. Assembly of poultry and other birds at fairs, shows or markets will be cancelled.

Vaccination

Vaccination of birds against AI is not always practical, effective or economical in any given outbreak situation. The CFIA has studied vaccination as a strategy against the spread of AI and has created guidelines around its effective use. Vaccination is certainly one of many strategies that the CFIA may employ during an AI outbreak. The CFIA is working with the United States Department of Agriculture, for access to a vaccine bank in the event of an AI outbreak.

Conclusions

The Government of Canada has attached a very high priority to the risks associated with the global spread of AI.

All available resources and expertise have been and continue to be applied to develop plans, policies and programs to help prevent the entry of AI in Canada and contain and eliminate outbreaks that may emerge. The foundation of Canada’s preparedness is built on the best science-based and most recent international intelligence and understanding available.

In the event of an AI outbreak in Canada, the CFIA, in concert with its government, industry, scientific and international partners, will provide the protection that Canadians expect and deserve through a decisive and rapid response that safeguards Canada’s poultry, food supply and economy.