There’s a study of the origins of the H1N1 virus appearing in Nature:
Closely related forms of the H1N1 strain of influenza virus circulated undetected in swine for years, a study published online June 11 in Nature reports. The virus, which has spread to multiple continents, has now been classified by the World Health Organization as a pandemic.
“Based on this report, we had a virus circulating in pigs for 10 years and nobody knew anything about it because we were not doing proper surveillance,†says Daniel Perez, an influenza expert at the University of Maryland in College Park.
Researchers traced the sordid past of the H1N1 virus by comparing mutations among different strains of the virus. Genetic sequences of 15 swine influenzas from Hong Kong and two human H1N1 viruses were compared with 796 sequences representing a large spectrum of related strains from humans, birds and pigs.
Analyzing numbers of mutations allowed an international team of researchers to estimate how long ago the strains first existed. Virus strains more than 90 percent identical to the current H1N1 strain were circulating in pigs between 9.2 and 17.2 years ago, the researchers found. The current strain “evidently spread without anyone noticing it for 10 years,†says Michael Worobey, an evolutionary biologist at the University of Arizona in Tucson and one of the study’s authors. “We need to spend more energy looking at what’s in pigs.â€
that hearkens back to the point I’ve been making here for some time. There are probably hundreds or thousands of strains of virus floating around, unnoticed until after they spread to humans and start making mischief. That may not be particularly heartening but it’s the reality. We can’t prevent or detect everything.
Or even halt their spread. This stuff was probably all around the world years ago.
Here’s a link to what Nature describes as a “near final version”.
