Is MRSA Contagious?

As long as there are viable MRSA bacteria in or on an individual who is colonized with these bacteria or infected with the organisms, MRSA is contagious. Consequently, a person colonized with MRSA (one who has the organism normally present in or on the body) may be contagious for an indefinite period of time. In addition, MRSA organisms can remain viable on some surfaces for about two to six months if they are not washed or sterilized.

For most staph infections, including MRSA, the incubation period is often indefinite if the organisms are colonizing (not infecting) an individual (see above). However, the incubation period for MRSA often ranges from one to 10 days if it enters broken skin or damaged mucous membranes.

MRSA is the short form of methicillin-resistant Staphylococcus aureus and refers to strains of gram-positive coccal-shaped (round) bacteria that are resistant to several antibiotics. MRSA causes mainly skin infections in nonhospitalized people; in hospitalized patients, it can cause sepsis, surgical site infections, and pneumonia. All of these infections may be difficult to treat because of MRSA's resistance to antibiotics.

Most MRSA skin infections first appear as a reddish bump that quickly becomes swollen, painful, and warm and contains or drains pus; they can occur almost anywhere on the body. The infected person may also develop a fever. Hospitalized patients may show surgical wound infections, pneumonia, or sepsis.

However, the definitive way to diagnose MRSA is to have a doctor culture the MRSA bacteria (skin lesion, biopsy, or nasal swab) and then show the organisms are resistant to several different antibiotics.

MRSA in the community is spread from person to person by direct contact; in addition, indirect contact is also a means of spread because the bacteria can survive on objects like towels, benches, shaving equipment, and other objects.

For a person to become infected, MRSA usually needs to have a breach (abrasion, cut, rash, or puncture) in the skin. Hospital spread of MRSA can include the above methods, in addition, to spread by blood, saliva, and/or droplets in the air that can land on people's skin or other surfaces if the person has pneumonia. Hospitalized patients who are MRSA carriers or infected with MRSA usually are put under isolation conditions (for example, gloves, masks, gowns, and minimized physical contact by visitors) to help prevent MRSA spread.

People who are colonized with MRSA are far less likely to transmit the organisms to others; transmission is more likely if the patient is infected with MRSA.

Many people are cured of MRSA when the symptoms resolve. However, a few individuals (about two of 100 people) carry MRSA as either transient organisms or colonizing organisms in some body areas such as the nasal mucosa but show no signs of infection. Occasionally, people can be cured of their carrier situation by topical antibiotics when they no longer are positive for MRSA cultures.

Prevention of MRSA infections may be accomplished by good hand washing and body cleaning hygiene practices, especially after playing contact sports or if people live in crowded areas (dorms, camps, or barracks, for example). Although cleaning clothing and other items helps reduce the chance of getting MRSA, using a disinfecting agent like bleach, when feasible, offers an even better chance of prevention.

• If you know you have had person-to-person contact with someone diagnosed with MRSA and you begin to develop any symptoms, contact a physician urgently.
• If you develop symptoms or signs that might be due to MRSA, contact a medical caregiver to help diagnose your condition with tests for MRSA.
• If you are being treated for an infection with antibiotics and the infection is not better or is getting worse and/or you are developing fevers, you should urgently or emergently, depending on the severity of symptoms, see a physician.