What is swine flu and where has it come from?

Swine flu is a respiratory infection caused by influenza type A. It usually affects pigs, but can be passed to humans. This is a new strain, probably created when two older swine flu viruses infected the same pig in Mexico. These then swapped genes to create a fresh strain

Do facemasks protect against infection?

Possibly, but the evidence is disputed. An Australian study found they can reduce the chances of infection, but only if worn properly and continuously. The Government has stockpiled 350 million masks for NHS staff, but there are no plans to distribute any to the general population

What are the symptoms?

Symptoms of swine flu are similar to those produced by standard, seasonal flu. These include fever, cough, sore throat, body aches, headache, chills and fatigue. Some people also have diarrhoea and vomiting

How do I know if I should see a doctor?

If you develop the symptoms above, and you live in places where swine flu cases have been confirmed or you recently travelled to Mexico, you should seek medical advice. Patients are being asked not to go into doctors’ surgeries to minimise the risk of spreading the disease to others. Instead, they should stay at home and call their healthcare provider for advice

Is it treatable?

Yes, with the flu drugs Tamiflu or Relenza, but not with two older flu medications

Is there a vaccine?

No. Now the strain has been isolated, it will take three to six months to produce one

How well prepared is the UK?

As well as it can be. The Government has bought 33 million courses of Tamiflu — the frontline antiviral drug — which is enough to cover half the population. Arrangements are also in place to buy a pandemic vaccine as soon as it is available. The World Health Organisation judges Britain and France as the best-prepared nations

Why has swine flu killed people in Mexico while causing only mild cases in the US?

Scientists do not know yet for certain, but the likeliest answer is that we have yet to discover the full extent of either outbreak. The virus has probably been circulating in Mexico for several weeks, but went undetected because it usually causes only mild symptoms — there may well have been hundreds of mild cases for every death that has occurred. The Mexican outbreak may simply be more advanced than the one in the US

Does that mean we can expect to see deaths in the US and elsewhere too?

Possibly. There will probably be more severe cases, but many of those who have died in Mexico were not treated promptly. The medical response will be swifter and more effective in countries like the US and Britain, and that will certainly save lives

How do I protect myself?

Take common sense precautions. Cover coughs and sneezes with a tissue that you throw away. Wash hands frequently. Adults should stay at home if sick, while children should be kept home from school

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