What is H1N1 or swine flu?
On this page: Definition | Recent History of H1N1 | Protect Yourself and Others | Back to Main H1N1 Page
Definition
H1N1 is the clinical term for the more commonly used term "swine flu."
Influenza A virus subtype H1N1, also known as A(H1N1), is a subtype of influenzavirus A and the most common cause of influenza (flu) in humans. Some strains of H1N1 are endemic in humans, including the strain(s) responsible for the 1918 flu pandemic, which killed millions of people worldwide. Less virulent H1N1 strains still exist today.
World Health Organization (WHO) definition
Swine influenza, or “swine flu”, is a highly contagious acute respiratory disease of pigs, caused by one of several swine influenza A viruses. Morbidity tends to be high and mortality low (1-4%). The virus is spread among pigs by aerosols, direct and indirect contact, and asymptomatic carrier pigs. Outbreaks in pigs occur year round, with an increased incidence in the autumn and winter in temperate zones. Many countries routinely vaccinate swine populations against swine influenza.
Swine influenza viruses are most commonly of the H1N1 subtype, but other subtypes are also circulating in pigs (e.g., H1N2, H3N1, H3N2). Pigs can also be infected with avian influenza viruses and human seasonal influenza viruses as well as swine influenza viruses.
The H3N2 swine virus was thought to
have been originally introduced into pigs by humans. Sometimes pigs can
be infected with more than one virus type at a time, which can allow
the genes from these viruses to mix. This can result in an influenza
virus containing genes from a number of sources, called a "reassortant"
virus. Although swine influenza viruses are normally species specific
and only infect pigs, they do sometimes cross the species barrier to
cause disease in humans.
Read more at WHO: World Health Organization.
Recent History of H1N1
In March and April 2009, an outbreak of H1N1 influenza in Mexico led to hundreds of confirmed cases and a number of deaths. As of April 28, the new strain was suspected to have infected more than 2,500 individuals worldwide, with 152 attributed deaths. The U.S. Centers for Disease Control and Prevention warned that it was possible the outbreak could develop into a pandemic. On April 27, 2009, the WHO raised their alertness level from 3 to 4 (on a scale of 6) worldwide in response to sustained human-to-human transfer of the virus. The situation was raised to level 5 (pandemic imminent) on April 29, 2009 by the WHO.
(Source: FightFlu.ca)
Protect Yourself and Others
All strains of influenza can be dangerous; however, good infection prevention measures can help protect you and others if this virus begins to spread rapidly in Canada.
- Wash your hands often and thoroughly in warm, soapy water or use hand sanitizer
- Cough and sneeze in your arm, not your hand
- Keep common surfaces and items clean and disinfected
- Stay home if you’re sick, unless directed to seek medical care
Prevent H1N1 flu virus (human swine flu) with frequent handwashing
Handwashing, when done correctly, is the single most effective way to prevent the spread of communicable diseases. Good handwashing technique is easy to learn and can significantly reduce the spread of infectious diseases among both children and adults.
Get more information on how to wash your hands.
Cover your cough and sneeze
Sneeze and cough into your elbow or sleeve or use a tissue. After wiping or blowing your nose with a tissue, throw away the tissue and wash your hands. Keep your fingers away from your eyes, nose and mouth
Stay at home and avoid crowds when sick
If you are sick, avoid going to work and being in large crowds as you can spread influenza easily to others. You should also visit those who are sick only if necessary.
Keep common surfaces clean
Keep personal items separate if a household member is sick. Use a disinfectant to clean surfaces around a person who is sick with the influenza. Do not share personal items or drinks.
Does the annual influenza vaccination protect me from H1N1 flu virus (human swine flu)?
This year’s annual influenza immunization, or flu shot, protects against the human strain of H1N1 influenza. The human swine influenza H1N1 strain is different than the human strain. It is unlikely that the seasonal flu shot will provide protection against H1N1 flu virus (human swine flu). The flu shot will protect against the seasonal influenza, which is still circulating in Mexico.
