Methicillin-resistant Staphylococcus aureus, commonly known as MRSA, represents a type of Staphylococcus aureus bacteria that has developed resistance to several common antibiotics, including methicillin, amoxicillin, and penicillin. While often associated with severe infections, MRSA can also reside harmlessly on the skin or in the nose. The presence of MRSA specifically within the nostrils, or nares, is a frequent occurrence for many individuals. This colonization does not always lead to illness but signifies that the bacteria are present on the body.
What is MRSA Nares?
MRSA is a strain of Staphylococcus aureus, a common bacterium found on skin and in the nose. While Staphylococcus aureus can cause various infections, from minor skin issues to serious conditions like pneumonia or bloodstream infections, MRSA is specifically resistant to several common antibiotics, including methicillin.
The nares, or nostrils, are a particularly common site for Staphylococcus aureus, including MRSA, to reside due to the moist environment and frequent hand-to-nose contact. When MRSA is present in the nares without causing any symptoms of illness, it is referred to as colonization. Many individuals can be colonized with MRSA for extended periods without ever developing an active infection.
Colonization means the bacteria are simply living on or in the body without causing harm or symptoms. In contrast, an MRSA infection occurs when the bacteria invade the body’s tissues, multiply, and cause signs of illness, such as redness, swelling, pain, pus, or fever. While colonization does not require immediate treatment in all cases, it does indicate a potential for future infection or transmission to others, particularly in healthcare settings or among vulnerable populations.
How MRSA Nares is Identified and Its Implications
Identifying MRSA in the nares involves a straightforward nasal swab. A healthcare professional gently inserts a sterile cotton swab just inside each nostril to collect a sample. This swab is then sent to a laboratory for culture; if Staphylococcus aureus grows, further tests confirm if it is resistant to methicillin, identifying MRSA.
Testing for MRSA nares colonization is not routine for everyone but is often done in specific situations. Patients scheduled for certain surgeries, like orthopedic or cardiac procedures, may be screened to reduce post-operative infection risk. Healthcare workers might also be tested as part of infection control protocols, especially during outbreak investigations. Screening helps identify carriers who might unknowingly spread the bacteria to more susceptible individuals.
A positive MRSA nares test indicates colonization. For many healthy individuals, nasal colonization with MRSA does not require immediate antibiotic treatment. However, it carries implications, including an increased risk for that individual to develop an MRSA infection in the future, especially if they undergo surgery, have weakened immune systems, or experience skin breaks. Colonized individuals can also transmit MRSA to others through direct contact, emphasizing infection control measures, particularly in communal or healthcare environments.
Managing MRSA Nares and Preventing Spread
Managing MRSA nares often involves decolonization strategies, particularly when an individual is at higher risk for infection or needs to prevent transmission. One common treatment is applying an antibiotic ointment, such as mupirocin, directly inside the nostrils. Mupirocin works by inhibiting bacterial protein synthesis, reducing MRSA bacteria in the nasal passages. This ointment is typically applied twice daily for five to seven days.
Antiseptic body washes containing chlorhexidine gluconate may also be recommended to reduce MRSA colonization on the skin. These washes are used for several days, often with nasal mupirocin, to target bacteria across the body’s surface. Decolonization treatments are generally considered for individuals undergoing certain surgeries, those with recurrent MRSA infections, or during healthcare facility outbreaks to reduce bacterial load and mitigate transmission risks.
Decolonization is not always necessary for all colonized individuals; a healthcare provider determines the appropriate course based on health status and risk factors. Even after successful decolonization, MRSA can sometimes return, as the bacteria are widespread. Therefore, ongoing general hygiene practices are important to prevent future colonization or spread.
To prevent MRSA spread, consistent handwashing with soap and water is paramount, especially after touching the nose, before eating, and after using the restroom. Avoiding sharing personal items like towels, razors, and athletic equipment also helps prevent transmission. Proper wound care, including keeping cuts and scrapes clean and covered, also helps prevent MRSA from entering the body and causing infection.