If you’ve recently been in the affected areas of Mexico and the US (see below) and are experiencing flu-like symptoms, stay at home and limit contact with other people.
You should then contact your GP or call NHS Direct on 0845 4647.
You do not need to worry if you have flu-like symptoms and have not recently been to the affected areas. Use our colds and flu symptom checker to get advice instead.
The symptoms of swine flu in people are similar to the symptoms of regular human seasonal flu infection. Symptoms include:
fever (high temperature),
lack of appetite,
Some people with swine flu have also reported having vomiting and diarrhoea.
The affected areas (as at 27 April 2009) are:
San Diego County, California, USA
Imperial County, California, USA
San Antonio, Texas, USA
Federal District of Mexico City, Mexico
San Luis Potosi, Mexico
Swine influenza (flu) is a respiratory disease (a condition which affect the breathing) of pigs caused by type A flu viruses. Outbreaks of swine flu regularly happen in pigs.
People do not normally get swine flu, but human infections can happen. Usually, human cases of swine flu happen in people who work closely with pigs. But it’s also possible for swine flu viruses to spread from person to person.
Recently, cases of human infection with swine flu A (H1N1) viruses have been reported in Southern California and near San Antonio, Texas.
And cases which are from the same virus (which come from an outbreak in Mexico) has shown wider human-to-human transmission of swine flu.
Yes. This virus is contagious and is spreading from human to human. But, at this time, we don’t know how easily the virus spreads between people.
Infection with the swine flu virus has been detected occasionally in humans since the 1950s. And the human disease is usually clinically similar to disease caused by infections with human flu viruses.
Cases of swine flu in humans usually occur after a history of exposure to pigs. For example, direct or close contact with infected pigs.
Person-to-person transmission, as suspected in the cases currently under investigation in the US and Mexico, have been previously reported but are rare.
There have been no cases identified in the UK for at least 10 years.
A single case of swine flu was reported in November 2008 in Spain. The person only had mild symptoms.
In the US there is an active swine flu surveillance programme to monitor pig viruses as they see more types of viruses than in any other country.
Flu viruses are commonly circulating in the human and animal environment. Different strains can cause illness in humans, bird and pigs.
Seasonal flu is caused by flu viruses that change to spread in humans (human influenza).
Humans have some natural immunity to the strains that are in common circulation. This immunity can be increased by immunisation with a seasonal flu vaccine (flu jab).
Avian flu is caused by flu viruses that affect birds. And, swine flu is caused by flu viruses that affect pigs.
These conditions all produce the same respiratory symptoms in their hosts.
Sometimes, humans and animals can pass strains of flu back and forth to one another. For example humans can become ill with avian or swine flu, usually from direct contact with animals who are ill.
Mixing of human and animal flu viruses can lead to the development of changed viruses with the ability to cause infection and spread in the human population. There may be little or no immunity in the human population to these new viruses.
A flu pandemic is defined as a new flu virus that spreads easily between humans.
When new flu viruses are introduced into the environment, humans don’t have any natural immunity to protect against them.
Therefore, there is a risk that new flu viruses could develop into a pandemic if the virus passes easily from human-to-human.
It is too early to say whether the cases in Mexico and the US will lead to a larger outbreak. Or whether it could represent the appearance of a potential pandemic strain of flu virus.
There is currently not enough evidence to understand the extent to which cases in Mexico and the US are firmly linked. Or to make a complete assessment of the health implications of this new virus.
The Director-General of the World Health Organization (WHO) is the decision maker in terms of declaring a flu pandemic.
Experts from around the world are working closely with the WHO to help determine what risk this situation has to global public health.
Testing has shown that the human swine flu H1N1 can be treated with the antivirals oseltamavir (Tamiflu) and zanamivir (Relenza).
General infection control practices and good respiratory hand hygiene can help to reduce transmission of all viruses, including human swine flu.
Covering your nose and mouth when coughing or sneezing, using a tissue when possible.
Disposing of dirty tissues quickly and carefully.
Maintaining good basic hygiene, for example washing hands frequently with soap and water to reduce the spread of the virus from your hands to face or to other people.
Cleaning hard surfaces (for example, door handles) frequently using a normal cleaning product.
You should make sure children and other members of your household follow this advice.