A view of a newspaper headline near Times Square in New York, New York, USA, on 27 April 2009. Countries around the world are reporting new cases of swine flu, a flu strain that has severely affected Mexico killing more than 80 people, and world organizations are warning of potential influenza pandemic. EPA/JUSTIN LANE
A woman walks through Times Square with a news ticker in the background in New York, New York, USA, on 27 April 2009. Countries around the world are reporting new cases of swine flu, a flu strain that has severely affected Mexico killing more than 80 people, and world organizations are warning of potential influenza pandemic. EPA/JUSTIN LANE
A passengers who has just arrived from Mexico City wears a protective maske at the airport in Frankfurt Main, Germany, 27 April 2009. The mask had partly been handed out to passengers by crew members. In general boarding and arrival procedures remained more or less unaffected at the major European airports, although further cases of swine flu were confirmed in the USA and Mexico. EPA/BORIS ROESSLER
A passenger who has just arrived from Mexico City wears a protective maske at the airport in Frankfurt Main, Germany, 27 April 2009. The maske had partly been handed out to passengers by crew members. EPA/BORIS ROESSLER
President Barack Obama speaks at the National Academy of Sciences in Washington, DC, USA, on 27 April 2009. President Barack Obama said he was closely watching an outbreak of swine flu in the United States, where 20 cases have so far been identified, but urged people to remain calm, saying that 'This is obviously a cause for concern and requires a heightened state of alert, but it's not a cause for alarm'. EPA/DENNIS BRACK / POOL
Main entrance to the Son Dureta hospital in Palma de Mallorca, Baleares Islands, Spain, 27 April 2009, were two people remain hospitalized with symptoms of swine flu. The Ministry of Health has confirmed the first case of swine flu in Spain, the first of Europe, while other twenty people are being analyzed for the flu. EPA/MONTSERRAT T DIEZ
A woman is seen on a crowded subway car in Grand Central Station in New York, New York, USA, on 27 April 2009. Countries around the world are reporting new cases of swine flu, a flu strain that has severely affected Mexico killing more than 80 people, and world organizations are warning of potential influenza pandemic. EPA/JUSTIN LANE
Guardia Civil members wear face masks at Barajas international airport, in Madrid, Spain, 27 April 2009. The Spanish government called for calm after Europe's first case of swine flu was confirmed among a total of at least 21 cases suspected in the country. EPA/JUAN CARLOS HIDALGO
The crew of a plane that has arrived from Mexico wears face masks at Barajas international airport, in Madrid, Spain, 27 April 2009. The Spanish government called for calm after Europe's first case of swine flu was confirmed among a total of at least 21 cases suspected in the country. EPA/JUAN CARLOS HIDALGO
Passengers walk past the main display panel at the airport in Frankfurt Main, Germany, 27 April 2009. Boarding and arrival procedures remain more or less unaffected at major European airports, although further cases of swine flu were confirmed in the USA and Mexico. EPA/BORIS ROESSLER
A man wearing a protective mask stands on a subway in Grand Central Station in New York, New York, USA, on 27 April 2009. Countries around the world are reporting new cases of swine flu, a flu strain that has severely affected Mexico killing more than 80 people, and world organizations are warning of potential influenza pandemic. EPA/JUSTIN LANE
A police officer looks out over the main concourse at Grand Central Station in New York, New York, USA, on 27 April 2009. Countries around the world are reporting new cases of swine flu, a flu strain that has severely affected Mexico killing more than 80 people, and world organizations are warning of potential influenza pandemic. EPA/JUSTIN LANE
Travellers arriving from Mexico City show their facemasks to reporters and answer questions at Amsterdam Schiphol Airport, Netherlands, 27 April 2009. EPA/GERALD VAN DAALEN
