Infectious Affection

Companion Animals Draw Scrutiny From Methicillin-Resistant Staph Investigatorsi>

Pets are good for people. Studies published by researchers in the U.S. and Europe, including work by MU's own Mary Beth Brown, have provided ample evidence that companion animals reduce owners' stress, encourage exercise, speed recovery after illness and, in kids especially, boost social skills and confidence levels.

Still, just to be on the safe side, you might want to stand clear the next time Fido sneezes. A new study of some 800 pets and their owners by a group of MU veterinary researchers will investigate whether our furry friends could be responsible, at least in part, for a rise in dangerous drug-resistant staph illnesses among human populations not previously thought to be at high risk.

Staph infections, according to the Centers for Disease Control and Prevention in Atlanta, are caused by Staphylococcus aureus, a bacteria found in the noses of some 25 percent to 30 percent of the public. Despite what you may have read in your local newspaper, the bacteria seldom make people sick. Still, some patients do contract potentially life-threatening bloodstream infections and pneumonia from staph -- illnesses made more complicated when the Staphylococcus aureus is of the difficult-to-treat, methicillin-resistant variety, or MRSA.

Because the bacteria infect human tissue by invading a cut or puncture, those who are immune-system compromised or who have recently had surgery comprise the majority of MRSA infections. The MU research team, made up of veterinary resident Stephanie Kottler, associate professor Leah Cohn and associate professor John Middleton, says this is changing.

"We used to think of these antibiotic-resistant infections as a healthcare issue that appeared in post-operative or long-term care patients," says Kottler. "However, we have been seeing more of these infections that have been acquired throughout the general population, or 'community acquired' infections. It's important to know what risk factors might be encouraging or prolonging these infections."

The CDC reports that during the past 20 years the number of MRSA infections has jumped from 22 percent to 63 percent of total staph illnesses. And though dogs and cats are far less likely to carry drug-resistant staph than humans, pets have been implicated as MRSA reservoirs in some cases. Thus, the researchers say, it's time to take a close look at pets' potential for fueling the MRSA surge.

"Are pets a risk factor?" asks Middleton. "This study will help us define whether pets are a risk factor for human MRSA infection and help us determine what questions the physician should be asking if a patient is diagnosed with MRSA."