Countries should remain on alert against the A/H1N1 flu virus in view of possible mutations, said a leading French virologist said in a recent interview with Xinhua.

Last Saturday, a swine herd in Canada was found caught the virus from a farm worker who traveled recently to Mexico, which again raised concerns over the spread of the virus from pigs to human and the safety of pork.

The chance that the A/H1N1 flu virus has a massive outbreak among pigs is remote because it has been finally proved that the virus was originated from humans, said Abdenour Benmansour, a virologist and molecular immunologist from French National Institute for Agronomy Research.

Despite the possibility that human may spread the virus to animals such as pigs and birds, it has to undergo mutations to accommodate to a certain species before it spreads far and wide among the species, he noted.

On the safety of pork, Benmansour said eating thoroughly-cooked pork is absolutely safe because the H1N1 virus spreads through air rather than foods.

However, those who have close contact with pigs, such as workers at slaughterhouses, are more vulnerable to the virus, he added.

Benmansour said people infected with the virus should avoid contacts with animals because the transmission between humans and animals could increase the possibilities of gene recombination among different viruses.

The world should remain on alert due to possible mutations of the virus, he said.

The development of Influenza A/H1N1 worldwide shows that the disease is not as serious as originally feared because it is treatable and some antiviral drugs proved effective in killing it, said the French expert, adding that it could even be taken as a common seasonal flu.

He said the outbreak could die down in summer because the virus is very sensitive to hot and dry weather.

In 1919, the pandemic of "Spanish Flu" killed some 50 million people worldwide. However, with current medical facilities and techniques unparalleled never before, Benmansour said he is confident that people could tide over the pandemic safe and sound as long as they take necessary precautionary and effective measures.

Mexican President Felipe Calderon announced on Monday that Mexico, epicenter of the epidemic affecting 21 countries, will return to "normalcy" on Wednesday, ending a five-day nationwide shutdown of the country's most businesses.

Mexican Health Minister Jose Angel Cordova on Monday brought the confirmed death toll to 26, with 727 total confirmed infections. The latest tally of confirmed sickened worldwide is 1,447.

(Xinhua News Agency May 5, 2009)