What is the difference between a common cold and influenza?

Influenza is different to a common cold, sinus infection or bronchitis. The symptoms of flu are usually worse and include fever, cough, extreme tiredness and body aches. If you have a cold, your head is affected the most and symptoms come on slowly. If you have flu, your whole body is affected and it comes on quickly.

It is important to know the difference between a cold and influenza. If you have influenza, stay home as much as you can and keep away from other people. Influenza spreads easily and can cause a lot of people to become unwell, especially during a pandemic (worldwide disease outbreak).

Are all cases of human swine influenza severe?

No. To date, the cases of H1N1 flu reported in Canada and in the United States are milder than those reported in Mexico. The cases reported in Mexico have been a little more severe, involving mostly young people. Some cases have rapidly progressed from mild illness to severe respiratory distress.

How long is the incubation period for human swine influenza?

The incubation period is the time between being infected and symptoms appearing.

Because this is a new type of influenza, urgent work is still being done to find out as much as we can about it. We know that people with seasonal influenza generally start having symptoms between one to four days after being infected. In the case of human swine influenza, symptoms usually start between two to four days after being infected.

For more information about human swine influenza, see the human swine influenza fact sheet at: www.emergency.health.nsw.gov.au/s wineflu/factsheets/swineflu.asp

How does human swine influenza spread?

Because this is a new type of influenza, urgent work is still being done to find out as much as we can about it. However, we think that human swine influenza is spread the same way as seasonal influenza.

Usually, seasonal influenza is spread from person to person when:

* someone breathes in the small droplets released into the air after a person with influenza coughs or sneezes; and when

* someone touches their nose, mouth or eyes after touching an object or surface that is contaminated by the influenza virus.

The virus can get onto surfaces or objects when droplets containing the virus land on them after an infected person coughs or sneezes, or from the hands of an infected person who touched them after they coughed or sneezed or touched their mouth, nose, or eyes. It is therefore important to always wash your hands after sneezing or coughing and frequently during the day.

For information about what to do when you have to cough, see the cough etiquette poster at: www.emergency.health.nsw.gov.au/s wineflu/resources/pdf/cough_etiqu ette.pdf

For information about how to wash your hands, see the poster at: www.emergency.health.nsw.gov.au/s wineflu/resources/pdf/hand_wash_c ommunity.pdf

Are people with human swine influenza infectious before they start showing symptoms?

Because this is a new type of influenza, urgent work is still being done to find out as much as we can about it. However we know that people with seasonal influenza are usually infectious from the day before symptoms begin until a few days after. It is likely that the same is true for people with human swine influenza.

For more information on seasonal influenza, see the general influenza factsheet at: www.health.nsw.gov.au/factsheets/ infectious/influenza.html

Fo r more information about human swine influenza, see the human swine influenza factsheet at: www.emergency.health.nsw.gov.au/s wineflu/factsheets/swineflu.asp

How long can an infected person spread human swine influenza to others?

Some aspects of the human swine influenza virus are still unclear. However, expert advice suggests that people with human swine influenza should be considered infectious as long as they have symptoms and for up to 7 days following illness onset. Children, especially younger children, could be infectious for longer periods.

How long can human swine influenza live outside the body?

Some viruses (including influenza virus) can live for 2 days or longer on surfaces like tables, doorknobs, and desks. Frequent hand washing will help you reduce the chance of getting an infection from these common surfaces.

Can I get human swine influenza from eating pork and pork products?

No. The swine influenza virus is not spread by food. You cannot get human swine influenza from eating pork or pork products. Eating properly handled and cooked pork products is safe.

How did human swine influenza infect humans?

Different types of influenza are commonly circulating in our environment, including types that can cause illness in humans, birds and pigs.

Sometimes, types of influenza can pass between humans and animals through close contact, such as in pig farms and livestock exhibits.

When pig or bird influenza viruses infect a human, there is a risk that the animal influenza can mutate (change its genes) and then spread directly between humans. The reason for the development of human swine influenza in Mexico is not known.

How easy is it for humans to catch influenza viruses from animals?

It is usually much more difficult for an animal type of influenza to infect a human, than it is for a human influenza type to infect a human. This is because the human types are much better adapted to the human body. However, the current situation with the new human swine influenza virus is that it contains gene segments from swine influenza and human influenza. This means that it has increased ability to infect humans.

Pigs are able to be infected with swine flu types, human types and bird types of influenza. The different viruses swap their genes when inside infected pigs and a new virus, which is a mix of swine, human or avian influenza can then emerge.

What is an influenza pandemic?

An influenza pandemic is a worldwide disease outbreak which occurs when:

* a new subtype of influenza virus emerges in humans to which most people have not been previously exposed and are, therefore, highly susceptible;

* the virus causes serious disease in humans; and

* the virus easily and quickly spreads between humans, infecting large numbers of people worldwide, and causing many deaths.

In the absence of immunity, a new type of influenza can spread rapidly across the globe, causing a pandemic.

Is this the beginning of a severe influenza pandemic?

Although it is clear that there are many cases across the world caused by this new human swine influenza virus, we are not sure how severe a pandemic, should it occur, will be. An influenza pandemic may be mild, moderate or severe. All pandemics can cause people to lose time from work due to illness, can increase the demands on the health care system and will lead to a number of people becoming seriously ill and dying.

The upgrading of Australia's response indicates the likelihood of a pandemic has increased, but not that a pandemic is inevitable.

Australian governments have robust and well rehearsed plans in place to deal with a pandemic, should one occur.

Why was the "Spanish flu" of 1918-19 so deadly?

The Spanish influenza virus of 1918-1919 had a much higher mortality than the influenza viruses from the other most recent influenza pandemics of 1957 and 1968, but it is not clear why this was the case. There may have been differences in the natural strength of the virus, causing people to become quite sick, or it may have been because of poorer living conditions in 1918. People in 1918 were also less well nourished than today, and did not have access to the same health services and medications we have today. It may be a combination of all these things that caused the influenza virus in 1918-1919 to be so serious. At the moment we do not know enough about the human swine influenza virus to be able to predict its eventual impact; however the information that many of the cases overseas have had only mild illnesses is encouraging.

How can I reduce the risk of getting human swine influenza?

To reduce the risk, take general preventive steps for seasonal influenza:

* Avoid close contact with people who appear unwell and who have fever and cough.

* Wash your hands with soap and water or alcohol-based hand cleanser frequently and thoroughly.

For protection against seasonal influenza, people can see their GP to get the annual influenza vaccination. It is unlikely that the seasonal vaccine will protect against the new human swine influenza. However, seasonal influenza will increase in the next few months and routine vaccination gives good protection against seasonal influenza. The influenza vaccination is free for some people, including those aged 65 years and over, and Aboriginal people aged 50 years and over.

For more information about seasonal influenza, see the general influenza factsheet at: www.health.nsw.gov.au/factsheets/ infectious/influenza.html

Fo r more information about human swine influenza, see the human swine influenza factsheet at: www.emergency.health.nsw.gov.au/s wineflu/factsheets/swineflu.asp

For information about current travel advice, see the Australian Government travel advice website at: www.smarttraveller.gov.au

What can I do to reduce the risk to myself and my baby if I am pregnant?

To reduce the risk to yourself, your baby and your family, take general preventive steps for seasonal influenza:

* Avoid close contact with people who appear unwell and who have fever and cough.

* Wash your hands with soap and water or alcohol-based hand cleanser frequently and thoroughly.

For more information about infection control for pregnant healthcare workers, see the factsheet at: www.emergency.health.nsw.gov.au/s wineflu/factsheets/infection_cont rol.asp

For protection against seasonal influenza, people can see their GP to get the annual flu vaccination. It is unlikely that the seasonal vaccine will protect against the new human swine influenza. However, seasonal influenza will increase in the next few months, and routine vaccination gives good protection against seasonal influenza. The influenza vaccination is free for some people, including those aged 65 and over, and Aboriginal people aged 50 and over.

For more information about seasonal influenza, see the general influenza factsheet at: www.health.nsw.gov.au/factsheets/ infectious/influenza.html

Fo r more information about human swine influenza, see the human swine influenza factsheet at: www.emergency.health.nsw.gov.au/s wineflu/factsheets/swineflu.asp

For information about current travel advice, see the Australian Government travel advice website at: www.smarttraveller.gov.au

Are some people more at risk?

More research is needed to find out if some people (for example, younger or older people, or people with other medical conditions) would be more vulnerable to an outbreak of human swine influenza, or if they are at higher risk for severe illness. It is recommended that everyone take steps to prevent the spread of infection.

How can I stop the spread of human swine influenza?

Because this is a new type of influenza, work is still being done to find out as much as we can about it. However, it is thought that human swine influenza is spread the same way as seasonal influenza.

Seasonal influenza is usually spread from person-to-person through coughing, sneezing, or through touching an object or surface contaminated by the influenza virus.

For more information about how the influenza virus spreads, see questions in the section 'About swine flu'.

There are many things you can do to reduce the risk of getting and spreading seasonal and human swine influenza:

Cover your mouth when you cough and wash your hands frequently.

* Cover your nose and mouth with a tissue when you cough or sneeze. Throw the tissue in the garbage bin after you use it and wash your hands.

* Wash your hands frequently with soap and water, especially after you cough or sneeze. Alcohol-based hand cleansers are also effective.

* Avoid touching your eyes, nose or mouth. That is how germs spread.

Try to avoid close contact with sick people.

* Influenza is spread from person to person through coughing or sneezing. Stay away from people who are sick.

* If you get sick, stay home from work or school and limit contact with others to avoid infecting them.

For information about what to do when you have to cough, see the cough etiquette poster at: www.emergency.health.nsw.gov.au/s wineflu/resources/pdf/cough_etiqu ette.pdf

For information about how to wash your hands, see the poster at: www.emergency.health.nsw.gov.au/s wineflu/resources/pdf/hand_wash_c ommunity.pdf

More information

More information can be obtained by ringing the Australian Government Department of Health and Ageing human swine influenza information hotline on 1802007.

Related Links

* NSW Health swine flu information page www.emergency.health.nsw.gov.au/s wineflu/index.asp

* NSW Health influenza factsheet (usual human influenza) www.health.nsw.gov.au/factsheets/ infectious/influenza.html

* Department of Health and Ageing - Health Emergency website www.healthemergency.gov.au

* World Health Organization www.who.int

* Travel Advice (Australian Government Department of Foreign Affairs and Trade) www.smartraveller.gov.au

* U.S. Centers for Disease Control and Prevention www.cdc.gov/h1n1flu

Ackn owledgements

Informatio n from a variety of government sources has informed these responses, including from the United States, Canada, United Kingdom and the World Health Organization.

Source: NSW HEALTH