MRSA and animals — an elephant, this time.

So, constant readers, I have wrestled another chapter to the ground — and thus have a few minutes' breathing space to talk about a story that some of you have asked about privately. I've been wondering whether to post on this, because the entire episode is in the book, and I don't want to scoop myself. But it's so interesting, and so sad, that it seems worthwhile.

This episode happened a year ago, and was reported at a couple of medical meetings last fall, but it is in the news now because it was written up last week in the CDC's Morbidity and Mortality Weekly Report or MMWR. (Which is the best-read magazine that you have never heard of. Hundreds of thousands of people all over the world read it every week for the latest in disease news. It's free. Go, already.)

So, the brief synopsis: In late January 2008, the San Diego Zoo's Wild Animal Park noticed that a baby African elephant, born in late November 2007, had broken out in pustules on her ear, neck, elbow and leg. Three of her caretakers had skin infections also. The zoo launched an investigation, assisted by a CDC Epidemic Intelligence Service officer who is assigned to California; they were concerned that the caretakers had unknowingly picked up a disease from the baby, who had been born early, was not thriving and was being intensively hand-reared by the zoo staff.

But in fact, it was more complicated than that. The pustules were MRSA, of course — but they were not ST 398, the animal strain that we have talked about so much here. Instead, they were USA300, the community-associated human strain that has zoomed to dominance all over the country. But there was no MRSA in the elephant herd, which the baby had not had contact with since late December. The reconstructed chain of transmission looked more like this: from an unknowingly colonized human to the baby elephant, who was medically fragile and had been isolated from her herd, and then from the elephant to the rest of the human "herd" who were caring for her. The strain involved was USA300, In the end, five human infections and three colonizations were laboratory-confirmed, and 15 other infections were suspected but not confirmed.

The humans recovered; most of their infections were so minor as to need no treatment, though three of them took oral antibiotics. The poor little elephant was not so lucky. She had multiple other illnesses, and she was euthanized on Feb. 4, 2008. The MRSA did not cause her death — by the time she died, the infection had resolved — but as one of the zoo staff told me, "It certainly didn't help."

So what does this tell us? Well, for zoo personnel, it tells them what to do for next time: More complete infection control especially around vulnerable animals. For microbiologists, it's an expansion of MRSA's range: No one had ever seen it in an elephant before.

For animal owners, it's a warning and reminder. We've known for a while that community strains can transiently colonize pets, staying in the animal's nose or elsewhere on the body just long enough to reinfect a human — in fact, an emerging piece of advice for physicians dealing with recurrent MRSA in families is, "Check the dogs and cats, too."

And for the rest of us, it suggests, one more time, how extremely adaptive and inventive MRSA is, and that we should never underestimate its ability to surprise.

MRSA article in Health magazine

After a long wait, some freelance articles that I've written on MRSA while researching the book have finally begun to be published! Here is the first, in Health magazine: an "as-told-to" by a Boston-area woman who struggled for more than a year with recurrent skin infections that just kept coming back:

The Truth About Staph
by Jilly Jackson* as told to Maryn McKenna
One woman’s harrowing tale of dealing with a dangerous infection called MRSA. How she got it and how it spread.
When I heard that high schools were closing and teenagers were dying because of the MRSA superbug, I felt lucky. Since the middle of 2006, I’ve had methicillin-resistant Staphylococcus aureus six times and somehow managed to avoid the worst: I’ve never been hospitalized and don’t fear for my life.

Link here and sidebar here.
Also, a CNN.com version — which has generated some great new leads for me! — here.