What's Happening Now?

A pandemic is a global disease outbreak. A flu pandemic occurs when a new influenza virus emerges for which people have little or no immunity, and for which there is no vaccine. The disease spreads easily person-to-person, causes serious illness, and can sweep across the country and around the world in very short time.

The threat of a pandemic has been raised to level 5 by the World Health Organization (WHO). This indicates that a novel virus has begun to spread around the world and that person-to-person transmission is occurring in multiple countries. At this time it is impossible to predict if this virus will become a pandemic or how severe a pandemic arising from this virus would be. Countries might, through measures such as border closures and travel restrictions, delay arrival of the virus, but cannot stop it.

To date the H1N1 virus has been detected in many countries including Canada, Mexico, the United States, throughout Europe and Asia. Although at this time the majority of cases reported outside of Mexico have been mild there is a concern that as numbers of cases increase we will see cases of more severe illness and deaths. Currently, the Public Health Agency of Canada (PHAC) is advising against non-essential travel to Mexico and the Emergency Operations Center has been elevated to full operation. Surveillance is underway to monitor all suspected cases of Influenza A (H1N1) in Canada. If you experience flu like symptoms report them to your health care professional.

Canada also has the first suspected case of a human transferring the Influenza A (H1N1) to a pig. A farm in Alberta has been quarantined to prevent the spread of the virus to other farms. The is no risk of contracting Influenza A (H1N1) from the consumption of well-cooked pork.

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Influenza A Viruses (Swine and Avian)

Avian and Swine flu are caused by influenza A viruses that occur naturally among these animals. There are different subtypes of these viruses because of changes in certain proteins (hemagglutinin [HA] and neuraminidase [NA]) on the surface of the influenza A virus and the way the proteins combine.

Each combination represents a different subtype. The current threat is represented by H1N1 which contains a combination of genes from swine, avian and human influenzas.

Symptoms include chills and cough followed by fever, loss of appetite, muscle aches and fatigue, runny nose, sneezing, watery eyes and throat irritation. Nausea, vomiting and diarrhoea may occur in adults as well as in children. In more severe cases, or in people with chronic conditions, complications such as pneumonia may develop.

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H1N1 in domestic animals

Although it was originally reported that the current H1N1 virus was a swine flu, it has been determined that this strain contains swine, avian and human strains of the influenza A virus. Pigs are known to be able to act as a `mixing vessel` permitting the reassortment of various strains of influenza and the development of a novel influenza strain. There is currently a single case of a herd with Influenza A H1N1 in Canada. In this case, it is suspected that the pigs obtained the virus from a farm worker who returned from Mexico. At this time the Canadian Food Inspection Agency is recommending increased surveillance and reporting of possible cases in pigs. If you are ill with suspected Influenza A (H1N1) and have contact with pigs you should avoid the animals until your symptoms resolve.

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Human Infection with Influenza A (H1N1)

"Human influenza virus" usually refers to those subtypes that spread widely among humans. There are only four known A subtypes of influenza viruses (H1N1, H1N2, H3N2, and H7N2) currently circulating among humans. Influenza A viruses are constantly changing, and other strains might adapt over time to infect and spread among humans.

Symptoms of Influenza A (H1N1) in humans are chills and cough followed by fever, loss of appetite, muscle aches and fatigue, runny nose, sneezing, watery eyes and throat irritation. Nausea, vomiting and diarrhoea may occur in adults as well as in children. In more severe cases, or in people with chronic conditions, complications such as pneumonia may develop.

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Vaccination and Treatment for Influenza A (H1N1) Virus in Humans

There currently is no commercially available vaccine to protect humans against this H1N1 virus that began in Mexico and has spread worldwide. A vaccine specific to the virus strain will be in development as soon as the targets can be identified. It is expected to take 6 months from the identification of a novel pandemic virus to the availability of a vaccine.

The Canadian Federal Government, through the Public Agency Health of Canada addressed the problem of a lag in a number of ways. These included:

• collaboration with industry to increase the Nation's vaccine production capacity
• seeking ways to expand or extend any supplies of antiviral drugs for treatment
• conducting research into the development of new types of influenza vaccines

Studies done in laboratories suggest that some of the prescription medicines approved in Canada for human influenza viruses should work in treating the current strain of H1N1 influenza infection in humans. However, influenza viruses can become resistant to these drugs, so the current strain of influenza is being monitored closely for resistance to drugs that are normally used to treat human influenza.

The current strain of H1N1 virus that is causing disease is resistant to amantadine and rimantadine, but remains remains susceptible to oseltamavir (Tamiflu) and zanamavir (Relenza). These drugs can be used to treat the H1N1 virus. For more information about H1N1 drug and vaccine development, see Pandemic Flu Vaccination and Anti-Virals Information

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What would be the Impact of a Pandemic?

A pandemic may come and go in waves, each of which can last for six to eight weeks. An especially severe influenza pandemic could lead to high levels of illness, death, social disruption, and economic loss. Everyday life would be disrupted because so many people in so many places become seriously ill at the same time. Impacts can range from school and business closings to the interruption of basic services such as public transportation and food delivery.

A substantial percentage of the world's population will require some form of medical care. Health care facilities can be overwhelmed, creating a shortage of hospital staff, beds, ventilators and other supplies. Surge capacity at non-traditional sites such as schools may need to be created to cope with demand.

The need for vaccine is likely to outstrip supply and the supply of antiviral drugs is also likely to be inadequate early in a pandemic. Difficult decisions will need to be made regarding who gets antiviral drugs and vaccines.

Death rates are determined by four factors: the number of people who become infected, the virulence of the virus, the underlying characteristics and vulnerability of affected populations and the availability and effectiveness of preventive measures.

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How have we prepared?

Canada has been working closely with other countries and the World Health Organization (WHO) to strengthen systems to detect outbreaks of influenza that might cause a pandemic.

The effects of a pandemic can be lessened because of the preparations made ahead of time. Planning and preparation information and checklists are prepared for various sectors of society, including information for individuals and families.

The Public Health Agency of Canada and other federal agencies are providing funding, advice, and other support to your province to assist with pandemic planning and preparation. Information on provincial/federal planning and cooperation, including links to province pandemic plans, is available on this site.

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What should You do?

Below are general guidelines, on what you should do to prevent the spread of influenza in general and what you should do in the event of a pandemic influenza. For more detailed guidelines and instructions please click individual/public pandemic planning guidelines, checklists and etc.

During every flu season, even when there is no pandemic, you should:

• If eligible, vaccinate yourself and members of your family against influenza. Regional health authorities provide flu immunization programs every year.
• Cover your mouth when coughing or sneezing, and immediately wash your hands. This helps prevent the spread of infectious diseases, including the common cold and the flu.

If you develop the flu, follow general guidelines to take care of yourself:

• Rest.
• Drink plenty of fluids.
• Take acetaminophen for fever or pain.
• Wash your hands to prevent further spread of the disease.

During a pandemic, you should:

• Be alert to information on radio and newspapers. Your regional health authority will advise you about the availability of immunization and any steps you can take to avoid disease.
• Health professionals will provide care to the very ill and provide information on self-care or caring for family members at home.

History of Pandemics

• H5N1 (Bird Flu) Timeline (PDF - 116 KB) (WHO)
  
  View the above WHO timeline to see the progression and major activity of H5N1 in both animals and humans since 1996.
   
  
• Experts Say Further Review of 1918 Pandemic Studies Key to Influenza Preparedness (National Institute of Allergy and Infectious Diseases)
  Read why researchers are looking to the 1918 influenza pandemic to help further preparedness efforts today.
   
  
• Timeline of Human Flu Pandemics
  (National Institute of Allergy and Infectious Diseases)
  
  See a chronology of significant dates in pandemic influenza history.
   
  
• The Deadly Virus: The Influenza Epidemic of 1918
  (National Archives and Records Administration)
  
  View archival documents and photos from the era of the Great Pandemic of 1918.
   
  
• The American Experience, Influenza 1918 (Public Broadcasting Service)
  
  Read the history of "the worst epidemic the U.S. has ever known".
   
  
• Influenza Pandemics of the 20th Century
  (Centers for Disease Control and Prevention)
  
  Read the history of "the worst epidemic the U.S. has ever known"
   
  
• Swine Influenza A Outbreak, Fort Dix, New Jersey, 1976
  (Centers for Disease Control and Prevention)
  
  Find out how the Swine Influenza A Outbreak affected the health of the Fort Dix soldiers in 1976.
   
  
• The Swine Flu Episode and the Fog of Epidemics
  (Centers for Disease Control and Prevention)
  
  Read about the lessons learned from previous epidemics.

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