Merriam-Webster's on-line dictionary defines a pandemic as "occurring over a wide geographic area and affecting an exceptionally high proportion of the population". In terms of illness, it is an outbreak of any disease such as typhoid or influenza (the "flu"). In comparison, an epidemic is similar but the disease affects a large number of people within a population, community, or region at the same time where as a pandemic is the same disease on a much larger more global scale.
Pandemic influenzas are caused by a new strain of the influenza virus. Because the virus is new, humans do not have an immunity to it and the illness is usually more severe. There is also no vaccine available. Historically a new strain appears 3 or 4 times a century or about every 30 or 40 years. The last outbreaks were:
A pandemic flu was declared by the World Health Organization (WHO) in June 2009 due to the emergence and quick spread of the H1N1 (Swine) flu virus.
Influenza is caused by three types of viruses called influenza A, B, and C. Influenza types A and B are responsible for the respiratory disease that occurs almost every winter. Influenza type C usually causes a very mild disease, often without symptoms. Only type A influenza causes pandemics in humans.
Certain conditions have to be met for a pandemic to occur:
It is impossible to predict the impact or death rate of a new influenza virus. WHO has estimated that 2 to 7.4 million deaths may occur as based on the 1957 influenza characteristics. Both the Asian (2 million deaths) and Hong Kong (1 million deaths) flus were milder and caused by a combination of human and avian viruses. In comparison, the Spanish flu is considered "exceptional" and caused the highest number of known deaths (40 to 50 million) worldwide and was likely to have been only avian virus in origin.
In addition, pervious influenzas were able to spread around the world in 6 to 9 months but these events occurred when most travel was by boat. With international air flights, a "modern" pandemic is expected to spread to all parts of the world in less than 3 months.
A pandemic will not be a "one time" event and periods of illnesses may come in 2 or 3 "waves" anywhere from 3 to 12 months apart.
To date the H1N1 virus is noted for its ability to spread very quickly. However, WHO considers the severity of the illness to be moderate as most people recover without the need for hospitalization or medical care. WHO continues to monitor this virus as "serious cases and deaths are occurring primarily in young persons, including the previously healthy and those with pre-existing medical conditions or pregnancy" (WHO, June 2009).
The most important step you can take to reduce the chance of infection is to wash your hands regularly - always wash regularly with soap and warm water.
See the OSH Answers Hand Washing - Reducing the Risk of Common Infections for more details.
Other steps you can take for personal hygiene are listed in Good Hygiene Practices - Reducing the Spread of Infections and Viruses.
Yes. Workplaces should prepare a plan that allows for normal business operations to continue when many people will be sick or absent. Estimates of how many people may be sick or absent range from 15-35% (Public Health Agency of Canada) to a high of 50% during the peak of a significant pandemic (New Zealand Ministry of Health).
When planning for a pandemic flu, remember a pandemic is not like the regular flu season, nor is it like a natural disaster (such as a hurricane or serious ice or snow storm). Remember, a pandemic will last much longer than a "one time" event and periods of illnesses may come in 2 or 3 "waves" anywhere from 3 to 12 months apart.
A business should plan for approximately one quarter to one third of employees being absent during a pandemic. While rare, some workplaces may need to close or be forced to close by order of a Medical or Public Health Office depending on the seriousness of the pandemic.
When creating a business plan, remember that:
Please see the booklet Business Continuity Plan: Infectious Diseases for more information.
As the pandemic "evolves", information may change quickly. The following web sites and telephone services are good sources for the most current information:
For public information about avian influenza or pandemic influenza,
You can also contact your local Ministry of Health or Public Health department for addition and local information. Check the blue pages of your telephone directory for these numbers.
Pandemic Influenza Home Page - from Government of Canada
Influenza (Flu) - Center for Disease Control and Prevention (CDC), USA
Pandemic Flu - U.S. Department of Health & Human Services
Pandemic (H1N1) 2009 - from World Health Organization
Document last updated on September 1, 2009