Claims that food-producing animals such as pigs are increasingly the source of methicillin-resistant Staphylococcus aureus (MRSA) bacteria in humans are greatly overstated, according to information from the Centers for Disease Control and Prevention (CDC).

The CDC says if transmission of MRSA from livestock to people occurs, “it likely accounts for a very small proportion of human infections in the United States.”

Studies in Canada and the Netherlands that found MRSA in pigs and pork producers on some farms have been used to link pigs, pork products and the use of antibiotics in livestock and poultry with the recent rise in MRSA cases.

“Statements connecting pork products and MRSA and linking the bacterial infection to the use of antibiotics in pigs are seriously misleading,” states Jill Appell, Altona, IL, pork producer and president of the National Pork Producers Council.

Dutch scientists conducted a risk assessment and concluded that MRSA present in pigs is not a food safety threat.

The CDC has conducted numerous investigations of community-based MRSA outbreaks, and “in none of these investigations has animal exposure been identified as a risk factor for infection.”

Research funded by the pork industry is studying whether MRSA is present in U.S. pigs. The industry has also established a panel of U.S., Danish and Canadian researchers to coordinate research efforts on MRSA in pigs.

MRSA is a common bacterium found throughout the environment and carried in the nasal passages and on the skin of more than 30% of the population. More serious forms of MRSA are found in hospitals, while less virulent forms are commonly found throughout the general population and on animals. A third, less-invasive form than the health care-associated forms of the bacteria, was recently discovered on some swine farms in the Netherlands and Canada.

Groups such as Keep Antibiotics Working are urging Congress to pass legislation to ban the use of subtherapeutic antibiotics in livestock because they claim it produces a proliferation of drug-resistant “super bugs.”