Swine flu emerged in Mexico months earlier than previously thought, the country's health minister has said, giving possible clues about the origins of the killer virus.
Officials had previously said that the first recorded case of the H1N1 virus in Mexico was from a woman who died in the southern state of Oaxaca on April 12.
However, in a news conference, Jose Cordova confirmed that a four-year-old boy in the eastern state of Veracruz had suffered from the virus as early as February. He survived the influenza.
A sample from the boy was sent to a US laboratory for anaylsis after swine flu was discovered in America.
"It came back confirmed," Mr Cordova said.
The announcement came as the probable death toll from the virus rose to 152.
The boy was one of about 1,800 people who suffered from a potent flu in the region in February, leading to calls to investigate if there was some kind of new epidemic.
However, Mr Cordova said there had been no evidence that a mutant human-to-human flu strain had emerged at that time.
"We never had this kind of epidemic in the world," he said. "This is the first time we have this kind of virus."
Mexico's Agriculture Department said that inspectors found no sign of swine flu among pigs in the region, adding that no infected pigs have been found yet anywhere in Mexico.
Swine flu has hospitalized almost 2,000 people in Mexico and spread to several countries including Britain, America, Spain and Israel.
Cases are also feared in New Zealand, Australia and South Korea.
The World Health Organization has raised its global alert level, signaling the swine flu virus was spreading from human to human in community outbreaks, but it stopped short of declaring a full-blown pandemic.
The WHO announcement in Geneva followed a decision by the top EU health official urging Europeans to postpone nonessential travel to parts of the US and Mexico because of the virus.
Source: telegraph.co.uk