WASHINGTON — No matter what you call it, leading experts say the virus that is scaring the world is pretty much all pig.

So while the U.S. government and now the World Health Organization are taking the swine out of "swine flu," the experts who track the genetic heritage of the virus say this: If it is genetically mostly porcine and its parents are pig viruses, it smells like swine flu to them.

Six of the eight genetic segments of this virus strain are purely swine flu and the other two segments are bird and human, but have lived in swine for the past decade, says Dr. Raul Rabadan, a professor of computational biology at Columbia University.

A preliminary analysis shows that the closest genetic parents are swine flu strains from North America and Eurasia, Rabadan wrote in a scientific posting in a European surveillance network.

"Scientifically this is a swine virus," said top virologist Dr. Richard Webby, a researcher at St. Jude Children's Research Hospital in Memphis. Webby is director of the WHO Collaborating Center for Studies on the Ecology of Influenza Viruses in Lower Animals and Birds. He documented the spread a decade ago of one of the parent viruses of this strain in scientific papers.

"It's clearly swine," said Henry Niman, president of Recombinomics, a Pittsburgh company that tracks how viruses evolve. "It's a flu virus from a swine, there's no other name to call it."

Dr. Edwin D. Kilbourne, the father of the 1976 swine flu vaccine and a retired professor at New York Medical College in Valhalla, called the idea of changing the name an "absurd position."

The name swine flu has specific meaning when it comes to stimulating antibodies in the body and shouldn't be tinkered with, said Kilbourne, 88.

That's not what government health officials say.

"We have no idea where it came from," said Michael Shaw, a director of laboratory science for the Centers for Disease Control and Prevention. "Everybody's calling it swine flu, but the better term is 'swine-like.' It's like viruses we have seen in pigs, it's not something we know was in pigs."

Yesterday, U.S. officials not only started calling the virus 2009 H1N1 after two of its genetic markers, but Dr. Anthony Fauci the National Institutes of Health corrected reporters for calling it swine flu. Then today, the WHO said it would stop using the name swine flu because it was misleading and triggering the slaughter of pigs in some countries.

Another reason the U.S. government wants to ditch the swine label is that many people are afraid to eat pork, hurting the $97 billion U.S. pork industry. Even the experts who point to the swine genetic origins of the virus agree that people can't get the disease from food or handling pork, even raw.

"Calling this swine flu, when to date there has been no connection between animals and humans, has the potential to cause confusion," Chris Novak, chief executive officer of the National Pork Board, said in a news release.

One top flu expert, doesn't like the swine flu name either, but for a different reason. Traditional swine flu doesn't spread easily among people, although this one does now, said Dr. Paul Glezen, a flu epidemiologist at Baylor University.

Columbia's Rabadan said sometimes when he talks to other scientists, he uses the name "swine" or the name "Mexican flu." And that name only adds another case of political incorrectness.

Mexico Health Secretary Jose Angel Cordova said it's wrong to call it "North American flu" and flatly rejects the idea of calling it "Mexican flu." He pointed to WHO information that the swine genes in the virus are from Europe and Asia. Rabadan and others say four of the six pure swine genetic markers are North American.

"I don't think it's fair for someone to blame Mexico for this. You can't blame any country; you can't blame a person or an institution. The recombination of genes in the virus is something that happens naturally," Mexico's chief epidemiologist, Miguel Angel Lezana said Wednesday.

And while the U.S. government and WHO are dropping "swine flu" as the name, someone hasn't told their Webmasters.

This afternoon, the phrase "swine flu" was still in the Internet addresses for the WHO, Homeland Security and CDC pages on the disease and the question-and-answer page on the U.S. government's pandemic flu Web site.