H1N1 Flu Genome Analysis Points to Multiple “Ancestors”
Posted Aug 27 2009 11:37pm
A genomic analysis of more than 50 samples of the A(H1N1) influenza virus shows that the virus has been evolving for a long time, probably decades. The particular combination of eight gene segments found in H1N1 have never previously been seen in samples from pigs or people. All of these genes originated in birds and later spread to pigs between 1918 and 1998.
This finding suggests that researchers need to more closely monitor pigs for new forms of flu virus.
Rebecca Garten of the U.S. Centers for Diseases Control and Prevention (CDC) and colleagues did the genomic analysis and are reporting their findings on the Science Express website sometime today. In other H1N1 news, a spokesperson for the CDC said it’s possible that older people are somewhat immune to H1N1 due to previous exposure to a similar virus, which would explain why the disease is spreading mostly among younger people and children. Apparently the disease is spreading among younger people, including children, faster than among the old.
The majority people infected in the U.S. so far have been between the ages of 5 and 24, while most hospitalized patients have been younger than 50.