Swine Flu May Have Evolved At US Hog Farms

With swine flu panic sweeping the globe, scientists appear to finally be getting closer to determining its origin -- and it's not quite as clear-cut as originally thought. The Wall Street Journal reports that the current problem may have actually begun in the United States.

A picture is now emerging of how U.S. and Mexican officials, with a key assist from a Canadian government lab, first realized they faced a new type of disease and began racing to isolate its earliest origins. Until recently, Mexico was widely assumed to be ground zero. Now, however, some California doctors are questioning that.

The four earliest confirmed cases are divided evenly between California and Mexico. In fact, it appears two children in California got sick in late March, several days before the first two known Mexico cases in early April.

And even if the first case was in Mexico, the United States won't get off scot-free, according to Grist's Tom Philpott. The virus may have evolved under US farming conditions before it made the jump to humans near the US/Mexico border:

In an interview with Science Magazine, the CDC's chief virologist, Ruben Donis' essentially confirmed the reading of the current swine flu strain made by New Scientist: that it evolved from a strain that cropped up in U.S. hog farms in 1998.

And then there's this amazing quote given to Wired's Brandon Keim:

“We haven’t found evidence of infected pigs,” said Ian Lipkin, a Columbia University epidemiologist and member of the World Health Organization’s surveillance network. “But even if we never find that smoking pig, we can surmise that this is probably where it came from.”