To: patron_anejo_por_favor who wrote (203915 ) 5/23/2009 3:29:28 PM From: Pogeu Mahone Respond to of 306849 youtube.com Swine flu genes may have circulated undetected for years By Randolph E. Schmid, Associated Press | May 23, 2009 WASHINGTON - Genes included in the new swine flu may have been circulating undetected in pigs for at least a decade, according to researchers who have sequenced the genomes of more than 50 samples of the virus. The findings suggest that pig populations need to be more closely monitored in the future for emerging influenza viruses, said a team led by Rebecca Garten of the Centers for Disease Control and Prevention in a report released yesterday by the journal Science. First detected last month, at least 42 countries now have confirmed the virus in more than 11,000 people - although those are only the cases tested, and authorities say many more have been sickened. Mexico has reported 75 swine flu deaths, the United States 10, and Canada and Costa Rica one each. How the new flu originated has taken a back burner to the more pressing work of treating the sick and trying to create a vaccine. But almost immediately, the CDC learned that the flu's parents were some older swine viruses - one of them a combination of pig, bird, and human strains - that had mixed genes in a new way. Yesterday's report takes a closer look at all of the genetic material of the virus, and found the closest ancestor for all eight gene segments is of swine origin. That suggests the virus might have been infecting pigs for years, even if the infected pigs didn't appear sick. The new work doesn't shed any light on where the H1N1 virus made its jump from pigs to people. Some of the genetic ancestors come from a virus that first hit US pig farms in 1998. Others are traced to pig viruses in Europe and Asia.