SUNDAY, April 29 (HealthDay News) --- Pork products from hogs fed salvaged pet food contaminated with the chemical melamine have a "very low" likelihood of harming human health, U.S. health officials reiterated Saturday night.

In a joint statement, the U.S. Food and Drug Administration (FDA) and the U.S. Department of Agriculture (USDA) stressed, "We are not aware of any human illness that has occurred from exposure to melamine or its by-products." They added that they have identified no illnesses in swine fed the contaminated feed.

The USDA first announced on Thursday that meat from 345 hogs suspected of eating the contaminated feed had entered the U.S. food supply. Some 6,000 hogs suspected of eating the contaminated product have since been quarantined and meat from these animals would be withheld from the food supply, both agencies said.

In the statement, the FDA and USDA said the possibility of human illness from eating swine exposed to melamine remains low for several reasons: "First, it is a partial ingredient in the pet food; second, it is only part of the total feed given to the hogs; third, it is not known to accumulate in the hogs and the hogs excrete melamine in their urine; fourth, even if present in pork, pork is only a small part of the average American diet."

All of this marks another chapter in the widening pet-food scare, which has so far led to the recall of more than 100 pet food products and the illnesses and deaths of an unknown number of dogs and cats.

In its latest statement, the FDA said it believes that melamine-tainted rice protein imported from China "was used in the production of pet food, and a portion of the pet food was used to produce animal [hog] feed."

The rice protein was imported to the United States by Wilbur-Ellis, an agricultural product importer and distributor. The FDA says it is continuing its investigation of the source of the adulterated pet food, including "tracing products distributed since August 2006 by Wilbur-Ellis throughout the distribution chain."

The FDA and USDA added that, as of Thursday, they have identified sites in six states where contaminated pet food was received and used in feed given to hogs: California, Kansas, New York, North Carolina, South Carolina and Utah.

On Friday, meanwhile, FDA officials searched the facilities of a pet food manufacturer and one of its suppliers in the continuing probe of the contaminated dog and cat food products, the Associated Press reported.

The officials searched an Emporia, Kan., pet food plant operated by Menu Foods and the Las Vegas offices of ChemNutra Inc., the news service said, citing information supplied by the companies.

Menu Foods made many of the major brands of dog and cat foods that were recalled because of melamine-contaminated wheat gluten. ChemNutra supplied Menu Foods with the wheat gluten, which was also imported from China but reportedly from a different supplier than the rice protein.

Both companies said they were cooperating with the investigation, the AP said.

The swine are thought to have been exposed to food contaminated by melamine and cyanuric acid, which were sent as salvage by companies who have had to recall massive quantities of dog and cat food as the pet food recall rolls on.

"Today we notified eight states that adulterated swine products will not be approved to enter the food supply," Capt. David Elder, director of the FDA's Office of Enforcement Office of Regulatory Affairs, said during a Thursday afternoon teleconference.

According to the AP, potentially contaminated pet food scraps may also have found their way to a poultry feed mill in Missouri. That case remains under investigation.

Like melamine, cyanuric acid is a chemical that can be used to boost the apparent protein content of foods. It is most often used as a stabilizer in outdoor swimming pools and hot tubs.

"The combination of melamine and cyanuric acid is of concern to human and animal health," Elder said. "Melamine, at detected levels, is not a human health concern."

The USDA will compensate hog farmers affected by the tainted pet food, Kenneth Peterson, an assistant administrator for field operations at the USDA Food Safety and Inspection Service, said during the Thursday teleconference.

"The pork and pork products from these animals will be destroyed," Peterson added. Each year, more than 105 million hogs are slaughtered in the United States, the AP noted.

On Thursday also, China banned melamine from its food products, but rejected the charge that the substance caused the pet deaths, the AP reported.

More information

For more information on pet food, visit the U.S. Food and Drug Administration.

SOURCES: April 28, joint statement, U.S. Food and Drug Administration and U.S. Department of Agriculture; April 26, 2007, teleconference with Capt. David Elder, director, Office of Enforcement Office of Regulatory Affairs, FDA, and Kenneth Peterson, assistant administrator, field operations, Food Safety and Inspection Service, USDA; Associated Press

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