DEAR DOCTOR K: I recently had a skin infection caused by MRSA. I must have picked this up at my mother's nursing home. How can I avoid another MRSA infection, as I hear they can be serious?
DEAR READER: MRSA is short for "methicillin-resistant staphylococcus aureus." Staph aureus is a bacteria. These bacteria are all around us. They live on our skin -- and if they get under the skin and multiply, they can cause a skin infection like the one you had.
But if staph bacteria get into the bloodstream, they can cause serious and potentially fatal infections.
Bacteria are remarkably resilient and can develop ways to survive drugs meant to kill or weaken them. This is called antibiotic- or drug-resistance. MRSA bacteria are resistant to an antibiotic called methicillin -- and methicillin was developed because staph and other bacteria had become resistant to penicillin.
It's a vicious cycle, an arms race. We invent antibiotics; bacteria develop resistance to them. So we invent new antibiotics, and the bacteria develop resistance to them. Sometimes bacteria can change faster than new antibiotics can be developed.
Antibiotic resistance is due largely to the increasing use of antibiotics, which are often prescribed unnecessarily and used inappropriately. You think you may have contracted your infection when you visited your mother's nursing home. One of the reasons MRSA infections are often contracted in health care facilities is that many patients are receiving antibiotics.
In fact, MRSA infections were first noted in the 1960s, in health care facilities. Twenty years later, they started appearing in the general community. Many MRSA infections that start in the community affect people who inject illegal drugs. Even house pets and other animals now sometimes carry MRSA and can pass them to humans.
MRSA infections don't produce worse symptoms than infections with staph that are not drug-resistant. Instead, the problem with MRSA infections is that they are harder to cure. MRSA infections may not respond to most (and in rare cases, any) of the currently used antibiotics.