In the wake of fears that the swine flu may spread, several countries have banned imports of pork produced in Mexico and the United States, according to the Christian Science Monitor. The Philippines has temporarily banned pork from all U.S. states and Mexico, while China, Russia, and Thailand have banned pork from Mexico and Texas, Kansas, and California. The National Pork Board, a U.S. industry association funded by the pork producers, has issued safety guidelines on its website for farmers and pork processors that include limiting the number of people coming in contact with the animals, preventing employees who display flu-like symptoms from contact with animals, and prohibiting access to operations of people who have recently returned from travel in Mexico. The Associated Press (AP) reports that Smithfield Foods, the largest U.S. pork producer, says it has found no evidence of swine flu in either herds or workers in the company's joint venture operations in Mexico but that it will submit samples to the University of Mexico for testing. AP says U.S. pork producers export nearly $5 billion worth of products each year, with Japan, Hong Kong/China, Mexico, Canada, and Russia the largest customers.