MRSA (short for Methicillin-resistant Staphylococcus aureus) is a bacteria that in the past was largely found in hospitals and other healthcare settings.
In recent years, a growing number of infections with MRSA have been seen outside of hospital settings both in the United States and elsewhere. In some places, MRSA is now the most common cause of certain infections. Some reports describe these microbes as multi-drug resistant Staphylococcus aureus (MDRSA) or as community acquired MRSA.
What kinds of problems does MRSA cause?
Community-acquired MRSA infections typically cause skin infections such as boils (furuncles), pimples (folliculitis), or cellulitis. These infections have sometimes been mistaken for “spider bites.” The skin may get red, painful, and swollen. The wound may drain pus as well. MRSA skin infections can occur anywhere on the body, but common sites for infection include the buttocks and groin.
MRSA infections can recur and take a long time to resolve completely in some cases. If left untreated, these infections can invade deeper tissues, sometimes necessitating more extensive tissue removal
In addition to skin infections, MRSA can less frequently cause other problems such as lung infections (pneumonias), blood infections, and other kinds of infections.
Who gets MRSA? What can I do to protect myself from MRSA?
Initial cases of MRSA outside of hospital settings were reported in a variety of different groups including sports teams, military recruits, children, prisoners, and men who have sex with men among others. MRSA is now commonly seen at Fenway and at other Boston hospitals. Researchers are currently conducting studies to try to better understand specific risk factors for MRSA infections.
Current evidence suggests that close contact with an infected person is an important risk factor for MRSA infections. Therefore:
MRSA, like other Staphylococcus aureus bacteria, can live in the nose and other skin surfaces of otherwise healthy people. This does not cause any symptoms. Sometimes for patients who have had multiple MRSA infections, doctors may recommend an antibiotic ointment or pill to attempt to get rid of this MRSA. There is currently insufficient evidence to support routine nose cultures followed by MRSA eradication treatments for otherwise healthy people.
How is MRSA diagnosed? What treatments are available?
MRSA skin infections can be detected by culturing pus from the wound.
In some situations, MRSA skin infections can be treated effectively simply by having your doctor drain the infected site. However, antibiotics are also commonly prescribed, and MRSA skin infections usually respond well to one of several medications such as Bactrim (trimethoprim-sulfamethoxazole). Antibiotics such as Keflex (cephalexin), dicloxacillin, clindamycin, or quinolones (like ciprofloxacin) that are often used to treat skin infections will not treat MRSA. If you believe that you have a MRSA infection, you should check with your doctor to see if the antibiotic you are prescribed will treat MRSA.
Deeper infections may need to be drained by a doctor in order to heal. Only a doctor should drain these infections.
What should I do if I think I have a MRSA infection?
Contact your healthcare provider.
It is important to seek medical attention early if you have a skin infection, because more advanced infections may require hospitalization and intravenous medications.
Be sure to let your healthcare provider know if:
Where can I go for additional information regarding MRSA?
Download a PDF file of the information on this page
Fact Sheet on MRSA (from the CDC)
MRSA Infection Overview (from MedlinePlus)
Annals of Internal Medicine article on multi-drug resistant staph in men who have sex with men (co-authored by The Fenway Institute)
Annals of Internal Medicine summaries for patients on multi-drug resistant staph in men who have sex with men
Recent Antimicrobial Agents and Chemotherapy paper on management of MRSA infections at Fenway