When a family physician in a small town in Indiana started seeing scores of patients with MRSA infections, he began to wonder whether nearby hog farms were incubating and spreading the disease.New York Times
columnist Nicholas Kristof
, writes about that doctor, Tom Anderson, and the pathogen, in his March 12 Op-Ed page column "Our Pigs, Our Food, Our Health.”
Dr. Anderson died of a heart attack or aneurism shortly before his scheduled meeting with Kristof. The columnist notes that Dr. Anderson had three bouts with MRSA himself, and that swine-carried MRSA has been linked to human heart inflammation. Dr. Anderson’s widow says her husband had treated more than 50 people with MRSA infections in a town with a population of about 500.
The most commonly known strain of MRSA, or methicilllin resistant Staphylococcus aureus, kills some 18,000 US hospital patients a year, and sickens thousands more, according to the federal Centers for Disease Control and Prevention. But there’s another strain, ST 398,
that has been identified as the predominant strain among swine in Canada and the Netherlands. Researchers say same strain accounts for 30 percent of staphylococcus found in humans in the Netherlands. Now, for the first time, the same strain ST 398 has been found in pigs and humans in the US. Tara Smith
, an assistant professor of epidemiology at the University of Iowa, is the lead author of a study published recently in the online Public Library of Science journal, PloS One
. She and colleagues sampled nares of 299 swine and 20 workers in hog "production systems” in Iowa and Illinois. They found 49 percent of the sampled swine and 45 percent of the sampled workers were carriers of MRSA ST 398. They conclude MRSA is common among swine, suggesting agricultural animals could become an important reservoir of the bacterium.
A story about the research by Maryn McKenna in The Scientific American
notes both the hospital acquired MRSA and ST 398, which is considered a community strain, are potentially deadly. Ms. McKenna’s story
quotes a professor of microbiology and infection control from the Netherlands as saying the unpredictability created by adding a novel strain to the evolving US MRSA epidemic is worrisome. "Strains change. They pick up new virulence, new resistance factors,” says the professor, Andreas Voss, who uncovered the first Netherlands MRSA case in 2004. "I believe it is a potential bombshell that it is here.”
A Dutch study has also found MRSA in several meat products
. It is not clear that the presence of the bacteria in meat presents a danger of transmissions to humans. Kristof notes there is no proven case of a human getting MRSA from eating pork. "I still offer my kids BLTs,” Kristof writes in his Times
column. "but I’ll scrub my hands carefully after handling raw pork.”
Kristof plans to write more on this. Watch for his column in The New York Times