Swine Flu

General information and frequently asked questions on Swine influenza or Influenza A

Updated May 2009

The World Health Organisation has predicted an influenza pandemic. History tells us that a flu pandemic occurs once every thirty to forty years. The latest pandemic scare is caused by the swine influenza. Pandemic flu has the ability to spread rapidly to affect most countries and regions world wide. The symptoms are very similar to those of normal flu, with the ability to spread rapidly.

Below are some of the most frequently asked questions about this pandemic:

• What is swine influenza?
• What are the implications for human health?
• Where have human cases occurred?
• How we are infected?
• Is it safe to eat pork meat and products?
• What about the pandemic risk?
• Is there a human vaccine to protect against swine influenza?
• What drugs are available for treatment?
• What should I do if I am in regular contact with pigs?
• How can I protect myself from getting swine influenza from infected people?
• What should I do if I think I have swine influenza?
• What can employers do?

What is swine Influenza

Swine influenza, or “swine flu”, is a highly contagious acute respiratory disease caused by the influenza A virus which infects pigs. There are many types, and the infection is constantly changing. Until now it has not normally infected humans, but the latest form clearly does, and can be spread from person to person - probably through coughing and sneezing.

Many countries routinely vaccinate pig populations against swine influenza. Although the swine influenza virus is most commonly of the H1N1 subtype, other subtypes also affect pigs. For example, pigs can also be infected with avian (bird) influenza virus and the human seasonal influenza virus. 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. This is the case in the latest outbreak.

What are the implications for human health?

Outbreaks and sporadic human infection with swine influenza have in the past been reported only occasionally. Generally clinical symptoms are similar to seasonal influenza but reported clinical presentation ranges broadly from asymptomatic infection to severe pneumonia which can be fatal. Since typical clinical presentation of swine influenza infection in humans resemble seasonal influenza and other acute upper respiratory tract infections, most of the cases have been detected by chance through seasonal influenza surveillance. Mild cases may have escaped recognition, therefore the true extent of this disease among humans is currently not known as the picture is unfolding everyday.

Where have human cases occurred?

The World Health Organisation (WHO) has been notified of swine influenza cases in the United States, Spain, Mexico and the UK and they are expecting more countries to announce further cases

How Humans become infected?

People usually get swine influenza from infected pigs, however, some human cases lack contact history with pigs or environments where pigs have been located. Human-to-human transmission has occurred in some instances but was limited to close contacts and closed groups of people. In the UK an increase in the number of confirmed cases is expected.

Is it safe to eat pork and pork products?

Yes. Swine influenza has not shown it is transmissible to people through eating properly handled and prepared pork (pig meat) or other products derived from pigs. The swine influenza virus is killed by cooking temperatures of 160°F/70°C, corresponding to the general guidance for the preparation of pork and other meat.

Which countries have been affected by outbreaks in pigs?

Swine influenza is not notifiable to international animal health authorities, therefore its international distribution in animals is not well known. The disease is considered endemic in the United States. Outbreaks in pigs are known to have occurred in North and South America, Europe (including the UK, Sweden, and Italy), Africa (Kenya), and in parts of eastern Asia including China and Japan.

What about the pandemic risk?

It is likely that most people, especially those who do not have regular contact with pigs, do not have immunity to swine influenza viruses that can prevent the virus infection. If a swine virus establish efficient human-to human transmission, it can cause an influenza pandemic. The impact of a pandemic caused by such a virus is difficult to predict as it depends on the virulence of the virus existing immunity among people, cross protection by antibodies acquired from seasonal influenza infection and host factors. Swine influenza viruses can give a rise to a hybrid virus by mixing with a human influenza virus and can cause a pandemic. The situation is currently being closely monitored and assessed by world health officials. To date it would appear that where swine influenza has affected humans the response to treatment is proving to be effective

Is there a human vaccine to protect against swine influenza?

No. Influenza viruses change very quickly and the match between the vaccine and the circulating virus is very important to give adequate protective immunity to vaccinated people. This is why the World Health Organisation needs to select vaccine viruses twice a year for seasonal influenza protection, one for the northern hemisphere winter and another for the southern hemisphere. Current seasonal influenza vaccine produced based on World Health Organisation recommendation does not contain swine influenza virus. It is unknown whether the seasonal vaccines can provide any cross protection to ongoing swine influenza virus. Infection in the United States and Mexico has meant that the World Health Organisation is working closely with its partner institutions around the globe

What drugs are available for treatment?

Antiviral drugs for seasonal influenza are available in some countries and these effectively prevent and treat the illness.

Most of the previously reported swine influenza cases recovered fully from the disease without requiring medical attention and without antiviral medicines.

Some influenza viruses develop resistance to the antiviral medicines, limiting the effectiveness of treatment. The viruses obtained from the recent human cases with swine influenza in the United States were sensitive to some drugs and resistant to others. Information is insufficient to make recommendations on the use of the antivirals in prevention and treatment of swine influenza virus infection.

How can I protect myself from getting swine influenza from infected people?

In the past, human infection with swine influenza was generally mild but is known to have caused severe illness such as pneumonia. For the current outbreaks in the United States and Mexico, the clinical pictures have been different. None of the confirmed cases in the United States have had the severe form of the disease and the patients recovered from illness without requiring medical care. In Mexico, some patients reportedly had the severe form of the disease and there are confirmed deaths.

To protect yourself, practice general preventive measures for influenza:

• Avoid close contact with people who appear unwell and who have fever and cough.
• Wash your hands with soap and water frequently and thoroughly. Anti bacterial soaps will help to reduce and kill germs
• Practice good health habits including adequate sleep, eating nutritious food, and keeping physically active. If there is an ill person at home:
• Try to provide the ill person with a separate section in the house. If this is not possible, keep the patient at least 1 metre in distance from others.
• Cover mouth and nose when caring for the ill person. Masks can be bought commercially or made using the readily available materials as long as they are disposed of or cleaned properly.
• Wash your hands with soap and water thoroughly after each contact with the ill person.
• Try to improve the air flow in the area where the ill person stays. Use doors and windows to take advantage of breezes.
• Keep the environment clean with readily available household cleaning agents.

Ensure that you are up to date with what national and local health authorities are advising in terms of protection and best practice.

What should I do if I think I have swine influenza?

If you feel unwell, have high fever, cough and/or sore throat:

• Stay at home and keep away from work, school or crowds as much as possible.
• Rest and take plenty of fluids.
• Cover your mouth and nose with disposable tissues when coughing and sneezing and dispose of the used tissues properly.
• Wash your hands with soap and water frequently and thoroughly, especially after coughing or sneezing.
• Inform family and friends about your illness and seek help for household chores that require contact with other people such as shopping.

If you think you need medical attention:

• Contact your doctor or healthcare provider before travelling to see them and report your symptoms. Explain why you think you have swine influenza (for example, if you have recently travelled to a country where there is a swine influenza outbreak in humans. Follow the advice given to you for care.
• If it is not possible to contact your healthcare provider in advance, communicate your suspicion of having swine influenza immediately upon arrival at the healthcare facility.
• Take care to cover your nose and mouth during travel.

What can employers do?

If a pandemic occurs employers should encourage workers to stay at home if they develop flu symptoms and consider sending home any member of staff who display flu like symptoms. This precaution should apply to those attending educational and similar establishments e.g. children / students and delegates attending meetings and conferences etc who are coughing and sneezing. In the event that there is flu pandemic the government will be making announcements in the newspapers on the television and radio stations. It may be that normal business is disrupted in order to control the spread of the pandemic

It is important that all employers consider establishing action plans now so that they are prepared or in a position to develop and execute a more detailed plan of action if necessary. The plan must be robust and developed in consultation with safety representatives. Where employees are engaging with the general public they need to be aware of any associated health risks.

The UK government has drawn up an influenza pandemic contingency plan. The plan recognises the extraordinary pressure and demands that are most likely to be placed on health care providers. To view this plan visit: http://www.dh.gov.uk/pandemicflu . The information provided has been recently updated. This will continue until there is a clear understanding of the possible pending pandemic.

Although the situation is still unfolding and it is unclear whether the current outbreak in Mexico will develop into a global pandemic, or what form any such pandemic would take, the following TUC guidance, which was produced in 2007 has now been updated (May 2009) and can be found at www.tuc.org.uk/pandemicflu In addition, the Health Protection Agency (HPA) will be producing advice should the situation develop. Guidance from the HSE can be found at the following link http://www.hse.gov.uk/news/2009/swineflu.htm Separate advice for health workers will be issued by the Department of Health and can be found on the following link http://www.dh.gov.uk/pandemicflu

The UK government has been developing a contingency plan for the past five years so we are well placed to managing the situation. We have a stock pile of drugs that will be made available for 33 million people - however the best advice is to ensure that employers and employees follow best practice and keep abreast of developments.