Androulla Vassiliou, EC health commissioner, today (April 27) warned people not to travel to parts of Mexico and the US hit by the outbreak in swine flu. She said travel should only be undertaken if it were "very urgent."
The warning came as the EC called an emergency meeting of health ministers to discuss the spreading outbreak and the first European case was confirmed in Spain.
EC president Jose Barroso said he was watching the situation carefully. Advice on travelling to Mexico was also updated by the UK Foreign and Commonwealth Office (FCO).
In the new advice, issued yesterday (April 26), business travellers are told the Mexican Health Ministry had issued a "nationwide alert" after people had died in "what appears to be a new form of influenza."
The message repeats the Mexican Secretariat of Health advice that people should "avoid large crowds, shaking hands, kissing people as a greeting, or using the subway."
It adds: "Maintaining a distance of at least six feet from other persons and frequent hand washing may decrease the risk of exposure."
Some corporates are already banning travel to Mexico. Nigel Tuner, Carlson Wagonlit Travel's director of public sector and industry affair for the UK, said: "What we are hearing from our clients is varied at this early stage.
"Several of CWT's clients are currently banning travel to and from Mexico or allowing only essential business travel subject to company approval.
"However the majority of CWT clients are closely monitoring the situation through the recommendations of the World Health Organisation (WHO) and Centres for Disease Control and Prevention (CDC).
"A few of our clients have asked CWT for reports on employees that have travelled to or from Mexico over the past few weeks to ensure employees that may have travelled through this area are being safely monitored."
Mexicana, the national carrier, was offering travellers the opportunity to change any flight booked between London Gatwick and Mexico City up to April 30.
A spokesman for the airline said it was keeping in touch with its head office in Mexico in case of any new developments. He said that while people were ringing up "concerned" about the situation, there were not really any cancellations." Mexicana runs four flights a week from the UK to Mexico City.
More than 100 people have so far died in Mexico from the respiratory disease which can be spread through coughing and sneezing. There are also a further 1,614 suspected cases in the country.
There are also 20 confirmed cases in the US and six in Canada. There are also suspected cases in the UK, France, Australia and New Zealand.
US president Barack Obama said the US cases were a cause for concern but not alarm. There were no signs this morning (April 27) of business travellers calling off trips to Mexico.
The UN said the virus could become a pandemic, but added the world was better prepared than ever to deal with any major threat. The World Health Organisation (WHO) is also expected to meet to discuss the threat from the virus.
BA and Iberia said they were both operating services normally and following advice from their respective health authorities. A spokesman for Iberia said: "Everything is being co-ordinated by the health ministry in Spain. We have 12 flights a week in from Mexico, and right now everything is normal."
"The situation right now is normal on our flights. Travel advice is not being issued by the airline but by the health ministry and the foreign affairs office." He said it was "too early to tell" if people were choosing not to fly.
BAA, which runs seven airports in the UK, including Heathrow and Gatwick said: "We're working closely with the Health Protection Agency (HPA) on this, and are issuing advice in partnership with them."
The HPA said: "We're not advising people not to travel at this stage, that would come from the Foreign and Commonwealth Office. Our advice is purely for people returning from abroad."
"What they can tell passengers when they get home is to watch their health for seven days. If someone is taken ill on the flight, they have guidance to follow from the IATA, and they have a duty to notify us and the airport health staff."
The International Air Transport Association said it was advising airlines to review their preparedness plans for public health emergency and consider how they may be implemented in the event that the current situation becomes more widespread.
"No specific additional measures are currently advised. Recommendations will be reviewed in light of World Health Organisation evaluation of the evolving situation."
Report by Stanley Slaughter