February 16th, 2009
12:51 PM ET

MRSA on the beach?

By Elizabeth Landau
CNN.com Health

Next time you go to the beach, you might want to shower - before you get in the ocean as well as after, says Dr. Lisa Plano, associate professor of clinical pediatrics and microbiology and immunology at the University of Miami.

A study she collaborated on shows that a person’s risk of exposure to staph is about 37 percent – but note that the bacteria could have come from you or from someone else. Your chance of getting MRSA, or methicillin-resistant Staphylococcus aureus, a form of antibiotic resistant staph, is about 1 percent.

Plano presented her research, conducted in subtropical marine waters, at the meeting of the American Association for the Advancement of Science in Chicago, Illinois, over the weekend. The study, which is the first large epidemiological study of its kind, looked at 1,300 people.

Preliminary data suggest that the number of people in the water increases number of bacteria in the water, she said.

The MRSA found in the study “looked like they were likely to cause aggressive infections, in the family of community-associated MRSA,” she said. The other staph, on the other hand, looked benign and unlikely to cause infections.

“We have to conclude that the beach could be a source for community-acquired staph infections,” Plano said.

MRSA has been around in hospital settings since the 1970s, but community-associated MRSA didn’t emerge until the late 1990s. Now, it is a recognized problem in situations where people come into close contact with one another's skin, such as in professional sports, as I reported in October. (read article)

But the researchers in this study could not make a link between the exposure to staph in the water and any illness in the participants, she said. While some people did have complaints, the data were not strong enough to draw a connection.

Still, while not wanting to scare anyone, Plano recommends that people shower before entering the water so they won’t spread their own bacteria, and afterwards so that they reduce the number of organisms they picked up.

What about acquiring staph from fish? Plano said she is unaware of a fish source that could transmit staph to humans, as these are largely human-specific bacteria. Note, however, that, cats and dogs can have staph too.

Is getting a staph infection something you think about at the gym or the beach?

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