I'm not a doctor, but this is what I know. Staph is a common bacteria found on the skin and in the nose of healthy people.

Sometimes it gets in the body and causes an infection. Person to person contact is the common way it is spread, secretions from infected skin lesions, nasal discharge or hands.

MRSA is especially nasty as it is antibiotic resistant. I know it is most prevalant in the hospital setting, but obviously not unheard of outside of it. Like most infections, careful handwashing and coverage of open skin lesions should help.

Hope that helps.