13 March 2008

MRSA and cats - an earlier paper

In journalism, there sometimes arises a situation in which a reporter for a major outlet writes a story that is very similar to one that has already been published by a minor outlet, without crediting the minor outlet. We call it "bigfooting." It's not a compliment.

The flurry of attention to the new letter in the New England Journal of Medicine about a pet cat harboring MRSA and reinfecting the cat's owner has a whiff of bigfooting about it. The letter describes a German family with MRSA that particularly persisted in the wife/mother despite treatment until one of their three pet cats was swabbed and decolonized.

The three authors from the Bavarian Food and Health Safety Authority write, "There is evidence that companion animals, mainly dogs, harbor MRSA, and interspecies transmission has been shown in the members of a family and their dog. This case illustrates that MRSA transmission also occurs between humans and cats." There are five cites appended to the letter, on MRSA epidemiology and sequencing and MRSA in dogs. The inference that this is the first recorded case of cat-human MRSA exchange was picked up by several media outlets: — Associated Press, Reuters — and explicitly stated by HealthDay. com, whose story was carried by the Washington Post.

So, the bigfooting: This isn't the first report of cat-human transmission at all. A very nice paper published in December 2006 in Emerging Infectious Diseases (not NEJM, but not exactly obscure as it is published by the CDC) reports the first isolation of the CA-MRSA strain USA300 from a California cat along with an identical strain in the cat's human. And it shows up close to the top of a Medline search, so it wasn't exactly hard to find.

(There is also a 2005 Veterinary Microbiology paper that reports a PVL+ strain in a cat along with several from dogs, but the researchers didn't type the strains and were unable to say whether they were CA or HA; and two letters in the Veterinary Record in 2004 and 2006 citing multiple MRSAs in cats. Neither draw a direct link to human illness.)

OK, enough truth-squadding. Back to HAI and search-and-destroy soon.


Anonymous said...

Now will people stop letting their pets lick their plates?


Maryn McKenna said...

Of course my cats never do that.

To be fair (and clear, in case I wasn't): The original source of the MRSA in these situations is humans, not animals. The owners give it to the pets, who pass it back.