TORONTO — A bid to rebrand the swine flu virus to clarify that pigs aren't spreading it to humans may create more confusion than it clears, several public health experts, including the man who helped named the Ebola virus, said Thursday.

The World Health Organization announced it would stop using the term "swine flu," a nickname that has angered pork producers and led to a drop in pork sales worldwide.

On Thursday, Prime Minister Steven Harper referred to it as the Mexican flu.

And Alberto Lozano, spokesman for the Mexican embassy in Ottawa, said the name that the Mexican government is using is H1N1.

"That's the scientific name provided by the World Health Organization," he said. "For us, that's the name of it."

Dr. Karl Johnson, a retired U.S. scientist who led the response to the first known Ebola outbreak, said "political correctness" was going to confuse science and the public.

"It's called swine flu because of what is known and knowable about the virus," Johnson, former head of special pathogens at the U.S. Centers from Disease Control, said from his home in rural New Mexico.

Johnson said calling it a swine flu virus, shortened by the media and most others to swine flu, is in keeping with the accepted nomenclature of influenza, adding it was "crazy" to try to drop references to swine from the name.

WHO spokesperson Dick Thompson said in an email that the Geneva-based agency would refer to the virus simply as influenza A(H1N1).

The change comes after the agriculture industry and the UN food agency expressed concerns that the term was misleading consumers and needlessly causing countries to order the slaughter of pigs, he said in a report from Geneva.

"Rather than calling this swine flu ... we're going to stick with the technical scientific name H1N1 influenza A," he said.

Incredulous scientists retorted that there is already an influenza A(H1N1) virus that has been circulating among humans for decades. That virus caused the 1918 Spanish flu pandemic. It has spread among people for all but 20 years since 1918 and is the milder of the currently circulating human influenza A viruses.

When flu diagnostic tests look for H1N1 virus, it is for the human subtype that they are searching. And one of the three components in the seasonal flu shot protects against the human H1N1 viruses but not, early research suggests, against the swine H1N1.

The notion that the public, the health-care profession and the research community would be left without a way to distinguish between a garden variety flu subtype and the one that may trigger the next pandemic is unworkable, said Dr. Michael Osterholm, director of the Center for Infectious Diseases Research and Policy at the University of Minnesota.

"That's nuts," said Osterholm of the suggested new name. "We've got to get a better name."

"They've got to do something to distinguish it from the seasonal flu."

Pork producers, U.S. administration officials and the WHO's sister agencies for animal health, the International Organization for Animal Health (known as the OIE) and the Food and Agriculture Organization have all objected to the term swine flu.

They have argued that it creates the false impression that pigs are transmitting viruses to people on an ongoing basis or that eating pork products can lead to swine flu infection. Both of those are untrue.

In Egypt, 300,000 pigs were destroyed this week, apparently in response to the perceived threat.

The outbreak, now confirmed in 11 countries, is caused by a novel swine influenza virus that is a hybrid of two strains of swine viruses plus genes from avian and human flu viruses.

It is not yet known and maybe never will be known where it first jumped into people. But it has not been found to be infecting pigs and the WHO and others have said that pigs don't factor into the equation when one is looking at transmission patterns now.

Naming new pathogens or outbreaks is rife with opportunities to offend. For instance, it is accepted that the Spanish flu did not emerge from Spain, but the country's name is forever linked to the worst infectious disease outbreak in known history.

Johnson knew of this problem when he and others set out to name the horrid hemorrhagic disease they were seeing in the former Zaire (now the Democratic Republic of Congo) in 1976. So they named the disease after a tiny river with few residents dwelling along it that flowed near the site of the outbreak, Yambuku.

"And nobody ever screamed about Ebola," Johnson said.

Dr. David Heymann, a recently retired WHO official, was on the team that named Ebola. And in 2003 when a new and dangerous disease that caused deadly pneumonia emerged in Asia, he, Thompson and another WHO official holed up in a room to come up with a name that would not stigmatize.

They wanted something catchy that headline writers would use, something like AIDS, they later explained. And so severe acute respiratory syndrome or SARS was named.

Despite their well-intentioned effort, the name managed to offend people of the Hong Kong Special Administrative Region, which is written as Hong Kong SAR. Hong Kong was very hard hit by the disease and the similarities of the names link the city with a disease it would prefer to forget.

Under the rules of influenza nomenclature, viruses are named after where they are first found. The first of these novel swine viruses was found in California and is logged in genetic sequence databases as A/California/04/2009.

Calling it the California flu would likely lead to howls at least as loud as those emanating from swine producers.

Whether the public and the media will readily abandon the name "swine flu" remains in doubt, particularly if the alternative creates confusion.

Johnson said the WHO could try to come up with an alternative, but warned it needs to fit within the scientific nomenclature of influenza viruses.

"It ought to be called swine H1N1 2009," said Johnson. "That's where I would keep it because it tells the truth."

— With files from The Associated Press