What medications are there?

There are some drugs around that can effectively treat swine flu infection in humans - and many types of flu infections in humans. There are two main types:

• adamantanes (amantadine and remantadine)
• inhibitors of influenza neuraminidase (oseltamivir and zanamivir)

Most previous swine influenza human cases recovered completely without the need for medical attention.

What can I do to protect myself?

• Wash your hands regularly with soap
• Try to stay healthy
• Get plenty of sleep
• Do plenty of exercise
• Try to manage your stress
• Drink plenty of liquids
• Eat a well balanced diet
• Refrain from touching surfaces which may have the virus
• Do not get close to people who are sick
• Stay away from crowded areas if there is a swine flu outbreak in your area

If I am infected, how can I stop others from becoming infected?

• Limit your contact with other people
• Do not go to work or school
• When you cough or sneeze cover your mouth with a tissue. If you do not have a tissue, cover your mouth and nose.
• Put your used tissues in a waste basket
• Wash your hands and face regularly
• Keep all surfaces you have touched clean
• Follow your doctor's instructions

What is Swine Flu - Video The Centers for Disease Control and Prevention (CDC) Influenza Division has produced a video all about swine flu.

This video includes information on the signs and symptoms of swine flu, how swine flu is transmitted, what medicines are available to treat it and steps that people can take to help protect themselves from it. There are also some tips on what to do if you become ill with swine flu.

Where have pigs been infected?

As swine influenza infection among pigs is not an internationally notifiable disease we cannot be completely sure. Swine influenza infection among pigs is known to be endemic in the USA. Outbreaks have also occurred in other parts of North America, South American, Europe, Africa, China, Japan, and other parts of Asia.

What is the risk for human health?

Outbreaks of human infection from a virus which came from pigs (swine influenza) do happen and are sometimes reported. Symptoms will generally be similar to seasonal human influenzas - this can range from mild or no symptoms at all, to severe and possibly fatal pneumonia.

As swine flu symptoms are similar to typical human seasonal flu symptoms, and other upper respiratory tract infections, detection of swine flu in humans often does not happen, and when it does it is usually purely by chance through seasonal influenza surveillance. If symptoms are mild it is extremely unlikely that any connection to swine influenza is found - even if it is there. In other words, unless the doctors and experts are specifically looking for swine flu, it is rarely detected. Because of this, we really do not know what the true human infection rate is.

World on alert over Mexican killer swine flu

British officials are on high alert as scores of travellers return from the centre of the outbreak, Mexico that is sweeping the country at an alarming rate.

More than 100 people have died there after contracting a flu-like viru and there are believed to be 1,614 cases in the country.

The vast majority of suspected cases of H1N1 have been found in people who have recently returned to their home countries.

The World Health Organisation (WHO) has described the situation as a "public health emergency of international concern".

It has previously given warning the highly lethal mutant strain could create a global pandemic.

Ten "highly likely" cases have been reported in Auckland and swabs have been sent urgently to a WHO laboratory in Melbourne, Australia.

There have been nearly 20 cases in the United States but so far all of them have been described as "mild".

A 26-year-old Israeli man was hospitalised after returning from a trip to Mexico on suspicion of contacting swine flu.

A Health Protection Agency (HPA) spokesman said there had been no confirmed cases of human swine flu in the UK.

He added: "The HPA and the NHS have systems in place which will alert public health authorities of any unusual strain circulating in the UK."

A member of a British Airways cabin crew was taken to hospital with "flu-like symptoms" on Saturday after falling ill on a flight from Mexico City to Heathrow.

The man, who has not been named, has been taken to Northwick Park Hospital in Harrow, north-west London.

But a spokesman for Northwick Park Hospital said the cabin crew member did not have swine flu.

"I can confirm he does not have swine flu. All the tests have come back negative," he said.

Public health officials have gathered in Geneva for an emergency meeting and branded the outbreak "a public health emergency of international concern."

The WHO asked countries around the world to "intensify surveillance for unusual outbreaks of influenza-like illness and severe pneumonia".

Previous human cases of swine flu have been rare and were usually restricted to people who had direct contact with animals infected by the respiratory condition.

But some of the 103 who have died in Mexico were victims of a unique version of the disease – a combination of bird, pig and human viruses, which can be passed from person to person.

The agency described the outbreak as "unusual" and warranting "further investigation and vigilance" by other countries.

The disease also appeared to have reached New York after eight children tested positive for probable swine flu.

The pupils attend a private school in Queens where about 200 children fell sick with influenza-type symptoms last week, officials said.

Some had just returned from holiday in Mexico.

City health officials, who are also testing 30 children at a daycare facility in the Bronx, urged residents not to panic and said they had stored extra supplies of incubators and drug.

Two new cases have also been reported in Kansas while in Texas, a school has been closed and a family put into quarantine after three children fell sick.

"It has pandemic potential because it is infecting people," said Margaret Chan, the director-general of the WHO, as public health specialists gathered in Geneva for an emergency session on the outbreak.

The new vaccine-resistant strain – a previously unseen combination of pig, bird and human viruses – is causing panic in Mexico's capital, one of the world's biggest cities and where most of the victims lived.

Mexico's president, Felipe Calderón, published an order on Saturday that would give his government extraordinary powers to address a deadly flu epidemic, including isolating those affected by the rare virus, inspecting their homes and ordering the closure of any public events that might result in more infection.

The mayor of Mexico City has cancelled all public events for 10 days and schools, colleges and museums have closed.

Alarmed residents are stockpiling food to stay indoors, only stepping outside wearing protective masks handed out by the government or packing bags and leaving the city – an exodus that could spread the disease.

Most of the victims have been aged 25 to 45.

Medical personnel said symptoms began like normal flu, but then victims' temperatures shot up, with paralysing muscle aches.

More than 1,600 people have fallen ill in Mexico with the suspected flu.

Miss Chan said the strain was poorly understood.

"We do not yet have a complete picture of the epidemiology or the risk, including possible spread beyond the currently affected areas."

The current seasonal flu vaccine is not believed to offer any protection against the new strain, but the anti-viral drug Tamiflu appears to be effective.

Jose Angel Cordova, Mexico's health secretary, said the country has enough Tamiflu to treat one million people – only one in 20 people in greater Mexico City alone – and that the medicine will be strictly controlled.

In Mexico City, fear surged through the population of 20 million yesterday.

Froylan Velarde, nervously fingering a blue mask that covered his mouth and nose, hurriedly shoved suitcases into his car.

"I'm taking my family and getting out of here right now. Basically, we are running for our lives," said the 48-year-old engineer.

Mr Cordova appeared on national television to advise people to stay in their homes, keep away from public places and avoid physical contact.

"Those killed have not been in contact with animals," he said. "This probably started with pigs but has now mutated to pass between humans."

He said 20 of the 68 deaths are confirmed to be from the new strain of influenza, while tests were still being conducted on the other 48.

He said the genetic code showed the virus had originated in Eurasia and could have entered Mexico via Texas or California.

Many residents in the Mexican capital decided to stay with relatives in the countryside or take time off work.

Others kept to their regular routine while wearing face masks being handed out by the government.

"The worst thing is that you don't know who has this virus. Maybe your neighbour has got it. Maybe the guy in the corner shop or the restaurant has it," said Gisela Hernandez, a 34-year-old housewife.

Swine flu Mexico City becomes

A mixture of fear, suspicion and frustration set in across the country as the death toll from swine flu rose and the government took an increasingly tough position to stop it spreading.

Many of those who did venture out wore the blue face masks that were being handed out by soldiers at check points along the main avenues.

"It's like we're in a strange zombie movie or something," said Gerardo Garcia, a 23 year old student, hurriedly stocking up with groceries.

"You don't know who could be carrying this plague so it is best to just keep behind closed doors as much as possible."

A shutdown of all schools, universities, museums and theatres was extended to bars and discos, which the government decreed they could forcibly close if they did not shutter their doors voluntarily.

Sunday Masses normally celebrated by millions in this strongly Roman Catholic country were also cancelled - the first such closure since Mexico's religious wars of the 1920s.

Health workers on the ground were overwhelmed with people reporting the key symptoms of the epidemic such as coughs, aching muscles and diarrhoea - although many may have had traditional forms of flu.

In total, 1,300 people were fighting the virus in hospital beds across Mexico with as many as 81 people dying of the disease.

Feelings of anxiety also swept through the 1,000 strong British expatriate community in the city.

Bar owner Umair Khan, 35, of Wembley, London, said he was getting increasingly worried seeing how events were developing.

"Originally, I wasn't in a major panic. But now that everything is shutting down it shows how serious it is," Khan said. "I have been here for 11 years and I have never seen anything like this."

Mr Khan said he shut his business - A British-style pub called the Black Horse - on Saturday after the government decree.

"It's a loss of money but you can't be angry about it," he said. "The last thing I would want is for someone to die after getting sick in my bar."

School teacher Gavin Judd, 38, from Birmingham has also been given a holiday from work.

"My plans are to avoid to going out as much as possible," he said. "If this is serious enough for the government to shut my school then I think it is a very real threat."

Mr Judd said he had no immediate plans to leave Mexico City, but said he will go if the government continues the school shut down until the end of the summer.

However, some others were taking the threat less seriously.

Hugh Carroll, a 56 year old investment broker from Glasgow, said he was unconcerned about the virus.

"I'm not worried in the slightest. It's probably been over exaggerated," he said. "Most people here don't trust what the Mexican government say and I don't believe them either."

Mr Carroll said he had not heard the declarations from the World Health Organization. He planned to go out and meet friends as usual.

Some Mexicans shared this disbelief, alleging it could be some kind of government conspiracy.

"It's probably all just made up to keep our minds off the global recession," said Roberto Santino, a 60-year-old building site foremen.

"Our government has been using these tactics for years."

Mr Santino claimed new government powers to fight the virus - including the power to search suspects and houses - were just an excuse to trample on people's rights.

Another conspiracy theory was that warring drug cartels, who killed eight civilians in a grenade attack in September, could be behind the misery.

"Who knows what is going on. Are the narco cartels using a secret weapon?" asked Lionel Trujillo, a 42-year old salesman, nervously fingering a surgical mask covering his mouth and nose.

Those at health centres showed more frantic worry.

At the Santiago Acahualtepec public clinic in Mexico City's working class Iztapalapa neighbourhood, a queue of patients, mostly clad in face masks, packed out the waiting room and stretched into the street.

"My daughter started showing signs of the sickness overnight - her temperature has shot up and she has been in a lot of pain," said Maria Angeles Garcia, a 33-year old teacher, waiting anxiously to be seen. "I am just praying that she does not have this plague."

What is swine flu?

influenza type A virus, there are regular outbreaks among herds of pigs, where the disease causes high levels of illness but is rarely fatal.

It tends to spread in autumn and winter but can circulate all year round.

There are many different types of swine flu and like human flu, the infection is constantly changing.

Swine flu does not normally infect humans, although sporadic cases do occur usually in people who have had close contact with pigs.

There have also been rare documented cases of humans passing the infection to other humans.

Human to human transmission of swine flu thought to spread in the same way as seasonal flu – through coughing and sneezing.

The outbreak in Mexico seems to involve a new type of swine flu that contains DNA that is typically found in avian and human viruses.

The World Health Organization has confirmed at least some of the cases are caused by this new strain of H1N1.

"We are very, very concerned," World Health Organisation (WHO) spokesman Thomas Abraham said. "We have what appears to be a novel virus and it has spread from human to human... It's all hands on deck at the moment."

It is genetically different from the fully human H1N1 seasonal influenza virus that has been circulating globally for the past few years. It contains DNA that is typical to avian, swine and human viruses, including elements from European and Asian swine viruses

When any new strain of flu emerges that acquires the ability to pass from person to person, it is monitored very closely in case it has the potential to spark a pandemic.

The WHO is concerned but says it is too soon to change the threat level warning for a pandemic. However, it has convened an expert panel to consider whether to raise the alert level or issue travel advisories.

It might already be too late to contain the outbreak, a prominent US pandemic flu expert said.

Dr Michael Osterholm, a public health expert at the University of Minnesota, said given how quickly flu can spread around the globe, if these are the first signs of a pandemic, then there are probably cases incubating in other parts of the world already.

"Literally hundreds and thousands of travellers come in and out of Mexico City every day," Dr Osterholm said. "You'd have to believe there's been more unrecognised transmission that's occurred."

There is no vaccine that specifically protects against swine flu, and it was unclear how much protection current human flu vaccines might offer.

However, the CDC says two flu drugs, Tamiflu and Relenza, seem effective against the new strain. Roche, the maker of Tamiflu, said the company is prepared to immediately deploy a stockpile of the drug if requested.

Both drugs must be taken early, within a few days of the onset of symptoms, to be most effective. There have also been concerns that some forms of flu have been developing resistance to the drugs.

Scientists have long been concerned that a new flu virus could launch a worldwide pandemic of a killer disease.

A new pandemic flu virus could evolve when different flu viruses infect a pig, a person or a bird, mingling their genetic material. The resulting hybrid could spread quickly because people would have no natural defences against it.

The most notorious flu pandemic is thought to have killed at least 40 million people worldwide in 1918-19. Two other, less deadly flu pandemics struck in 1957 and 1968.