USDA starts surveillance of pigs for flu

The U.S. Agriculture Department will soon launch a pilot surveillance project to look for new strains of flu virus in pigs, including the new strain of H1N1 flu, Chief Veterinarian John Clifford said on Tuesday.

The program will examine samples from sick pigs voluntarily submitted to government and private labs, as well as any herds where a barn worker has been identified with the H1N1 flu, Clifford told Reuters.

"It's trying to be more proactive because these flu viruses can mutate or recombinate," Clifford said.

The new H1N1 virus has made more than 11,000 people in 42 countries sick, killed 86, and raised fears it could be a pandemic.

Scientists believe the virus, which contains a mixture of genes from human, pig and bird flu strains, was circulating undetected for years, most likely in pigs. But they do not know how the virus emerged in humans.

The USDA has not found the new strain of virus in U.S. pigs, Clifford said, noting government and private laboratories have searched their samples to see if any match.

"Currently, we have no reasons to believe it does" exist in U.S. pigs, he said.

Common swine flu causes fever and coughing in pigs. Like humans, animals usually recover from the illness. In the United States, farmers routinely vaccinate herds against the flu.

Flu viruses, which are airborne, can pass back and forth between people and pigs. Last month, Canadian officials said a carpenter sick with the H1N1 flu gave the virus to a herd of swine while working in a barn.

U.S. officials have reported 11 cases since 2005 where humans caught the flu from hogs, according to a March article in the Journal of the American Veterinary Medical Association.

World health officials have repeatedly stressed that the flu cannot be contracted from eating pork.

The USDA and U.S. Centers for Disease Control and Prevention began developing the surveillance program a year ago, Clifford said, well before the human outbreak of the new H1N1 virus.

The project, which includes research on the viruses, will rely on funding of $1.5 million from the CDC, Clifford said.

The USDA will use samples to update diagnostic tests and swine vaccines, he said.

Clifford said he did not know how many virus samples would be submitted to the program, noting it would depend on the severity of the next flu season.

"It's a little hard to forecast" the number of samples the voluntary program will receive from producers and veterinarians, Clifford said.

Because the flu is impossible to eliminate from the hog population - just as it is in humans - Clifford said he does not believe submissions of flu samples should be mandatory.