What is MRSA?

Methicillin-resistant Staphylococcus aureus (MRSA) is a bacterium that causes infections in different parts of the body. It's tougher to treat than most strains of staphylococcus aureus -- or staph -- because it's resistant to some commonly used antibiotics.

The symptoms of MRSA depend on where you're infected. Most often, it causes mild infections on the skin, causing pimples or boils. But it can also cause more serious skin infections or infect surgical wounds, the bloodstream, the lungs, or the urinary tract.

Understanding MRSA

MRSA is called a "super bug" because infections are resistant to many common antibiotics. Although most MRSA infections aren't serious, some can be life-threatening. Many public health experts are alarmed by the spread of tough strains of MRSA.

What causes MRSA?

Garden-variety staph are common bacteria that can live on our bodies. Plenty of healthy people carry staph without being infected by it. In fact, 25-30% of us have staph bacteria in our noses.

But staph can be a problem if it manages to get into the body, often through a cut. Once there, it can cause an infection. Staph is one of the most common causes of skin infections in the U.S. Usually, these are minor and don't need special treatment. Less often, staph can cause serious problems like infected wounds or pneumonia.

Staph can usually be treated with antibiotics. But over the decades, some strains of staph -- like MRSA -- have become resistant to antibiotics that once destroyed it. MRSA was first discovered in 1961. It's now resistant to methicillin, amoxicillin, penicillin, oxacillin, and many other antibiotics.

While some antibiotics still work, MRSA is constantly adapting. Researchers developing new antibiotics are having a tough time keeping up.

Who gets MRSA?

MRSA is spread by contact. So you could get MRSA by touching another person who has it on the skin. Or you could get it by touching objects that have the bacteria on them. MRSA is carried, or "colonized," by about 1% of the population, although most of them aren't infected.

MRSA infections are most common among people who have weak immune systems and are living in hospitals, nursing homes, and other heath care centers. Infections can appear around surgical wounds or invasive devices, like catheters or implanted feeding tubes. Rates of infection in hospitals, especially intensive care units, are rising throughout the world. In U.S. hospitals, MRSA causes more than 60% of staph infections.

Community-Associated MRSA (CA-MRSA)

But MRSA is also showing up in healthy people who have not been living in the hospital. This type of MRSA is called community-associated MRSA, or CA-MRSA. The CDC reports that in 2007, 14% of people with MRSA infections had CA-MRSA.

Studies have shown that rates of CA-MRSA infection are growing fast. One study of children in south Texas found that cases of CA-MRSA had a 14-fold increase between 1999 and 2001.

CA-MRSA skin infections have been identified among certain populations that share close quarters or experience more skin-to-skin contact. Examples are team athletes, military recruits, and prisoners. However, more and more CA-MRSA infections are being seen in the general community as well, especially in certain geographic regions.

It's also infecting much younger people. In a study of Minnesotans published in The Journal of the American Medical Association, the average age of people with MRSA in a hospital or healthcare facility was 68. But the average age of a person with CA-MRSA was only 23.

How Can I Prevent MRSA?

Staph is spread by contact. You can get MRSA if you touch a person who carries the bacteria -- or if you touch something that an infected person touched.

The CDC says that the following things have been associated with the spread of MRSA.

• Close skin-to-skin contact

• Openings in the skin, like cuts or abrasions

• Contaminated items and surfaces

• Crowded living conditions, like in hospitals or prisons

• Poor hygiene

In health care centers, people who carry MRSA are sometimes isolated from other patients to prevent the bacteria from spreading.

According to the CDC, here are some of the best ways to prevent MRSA.

• Wash your hands thoroughly. Use soap and water or an alcohol-based hand sanitizer. Experts suggest that you wash your hands for as long as it takes you to recite the alphabet.

• Cover cuts and scrapes with a clean bandage. This will help the wound heal. It will also prevent you from spreading bacteria to other people.

• Do not touch other people's wounds or bandages.

Do not share personal items like towels or razors. If you use any shared gym equipment, wipe it down before and after you use it. Drying clothes, sheets, and towels in a dryer -- rather than letting them air dry -- helps kill bacteria.

What Are the Symptoms of MRSA?

The symptoms of MRSA infection depend on where you've been infected.

MRSA most often appears as a skin infection, like a boil or abscess. It also might infect a surgical wound. In either case, the area would look:

• Swollen

• Red

• Painful

• Pus filled

Many people who actually have staph skin infections often mistake it for a spider bite.

If staph infects the lungs and causes pneumonia, you might have:

• Shortness of breath

• Fever

• Cough

• Chills

MRSA can cause many other symptoms since it can infect the urinary tract or the bloodstream.

Very rarely, staph can result in necrotizing fasciitis, or "flesh-eating" bacterial infections. These are serious skin infections that spread very quickly. While frightening, necrotizing fasciitis caused by staph is rare. There have only been a handful of reported cases.

Call Your Doctor About MRSA If:

See your health care provider if you have signs of active infection. In most cases, MRSA is easily treated. But since MRSA infection can be serious or -- rarely -- fatal.

If you are already being treated for an infection, watch for signs that your medicine isn't working. If you are taking an antibiotic, call your doctor if

• The infection is no better after three or four days

• The infection keeps getting worse

• You develop a fever, or your fever gets worse

People who are ill or have a compromised immune system have a higher risk of getting serious MRSA infections. If you have a condition that lowers your immunity, call your doctor right away if you think that you might have an infection.

Understanding MRSA Detection and Treatment

How Is MRSA Diagnosed?

Your health care provider will be able to run lab tests to see if you have MRSA. If you have an infection on the skin, your doctor will take a culture from the infected area. Depending on your symptoms, your doctor might test also your blood, urine, or sputum.

What Are the Treatments for MRSA?

The good news is that MRSA is treatable. By definition, MRSA is resistant to some antibiotics. But other kinds of antibiotics still work. Bactrim and Vancocin (vancomycin) are often the first drugs used. Other options are Cleocin, minocycline, Cubicin, Zyvox, and Synercid. Some of these antibiotics are only available intravenously. There is also emerging antibiotic resistance being seen with some of these medications as well.

Antibiotics aren't always necessary. If you have a skin boil, your doctor may just make an incision and drain it.

If you are prescribed antibiotics, follow your health care provider's instructions precisely. Never stop taking your medicine, even if you're feeling better. If you don't take all of your medicine, some of the staph bacteria may survive. These survivors then have the potential to become resistant to the antibiotic. They also could re-infect you or infect someone else.