Methicillin-resistant Staphylococcus aureus (MRSA) is a staph bacteria resistant to common antibiotics, including methicillin and penicillin. This resistance makes MRSA infections difficult to treat. While MRSA is hardy, an active infection is treatable with specialized medical therapies. A “cure” is complicated by the difference between clearing an active infection and permanently eliminating the bacteria from the body.
Distinguishing MRSA Infection from Colonization
MRSA exists in two states: colonization and active infection. Colonization occurs when the bacteria are present on the skin or inside the nose without causing illness or symptoms. About one in three people carry some form of Staphylococcus aureus on their body, and this carriage often causes no problems.
An active infection occurs when the bacteria enter the body through a break in the skin, such as a cut, wound, or medical device insertion site. This triggers the immune response, resulting in symptoms like redness, swelling, pain, or pus drainage. Treatment focuses on clearing the symptomatic infection, but the patient may remain colonized, complicating the idea of a permanent cure.
A colonized individual can still spread the bacteria to others, even if they are asymptomatic. An active infection, especially one with open wounds, carries a higher risk of transmission due to the large number of bacteria present.
Treatment Strategies for Active MRSA Infections
The primary goal is to eradicate the active infection, which can range from a localized skin issue to a life-threatening systemic illness. For localized skin infections, such as an abscess or boil, healthcare providers often perform incision and drainage (I&D) to physically remove the pus and bacteria.
I&D may be sufficient to clear minor skin infections without antibiotics. If the infection is severe, widespread, or if the patient shows signs of systemic illness like fever, antibiotics are necessary. Specific antibiotics must be chosen based on the strain’s susceptibility because MRSA is resistant to many common medications.
For mild-to-moderate outpatient infections, oral antibiotics such as trimethoprim/sulfamethoxazole (TMP/SMX), doxycycline, or clindamycin are prescribed. Patients must complete the entire course to prevent the bacteria from developing further resistance.
In cases of severe or deep-seated infections (e.g., pneumonia, bloodstream infections, or infections affecting the bones or heart), hospital admission and intravenous (IV) antibiotics are required. Medications like vancomycin, linezolid, and daptomycin are reserved for these serious conditions.
Eradicating MRSA Colonization (Decolonization)
Healthcare providers may recommend decolonization for individuals with recurrent MRSA infections or those preparing for high-risk surgeries. This process temporarily reduces the number of MRSA bacteria carried on the body, lowering the risk of future infection.
The standard decolonization protocol targets common colonization sites using two components. Patients apply a prescription antibiotic ointment, such as mupirocin 2%, inside both nostrils twice daily, as the nose is a frequent reservoir.
Simultaneously, patients perform daily full-body washing with an antiseptic soap, typically a 4% chlorhexidine gluconate (CHG) solution. The ointment and wash are used together for five to ten days to eliminate bacteria from the nasal passages and the skin surface.
Decolonization does not guarantee a permanent MRSA-free state, as the bacteria can return. It is sometimes repeated for patients with persistent recurrence or before subsequent high-risk medical procedures.
Managing Recurrence and Preventing Transmission
After an MRSA infection is successfully treated, long-term management focuses on preventing recurrence and limiting spread. Maintaining rigorous personal hygiene is the most effective preventative measure. This includes frequent and thorough handwashing with soap and water or using an alcohol-based hand sanitizer.
Individuals should keep all skin breaks, cuts, or abrasions clean and covered with a fresh bandage until fully healed. Covering the area prevents surface contamination, as pus or fluid from infected wounds contains high concentrations of MRSA.
Avoid sharing personal items that contact the skin, such as towels, washcloths, razors, or athletic gear. Clothes, bedding, and towels should be washed in hot water and dried on a high heat setting to eliminate bacteria.
If an individual has a history of MRSA, they should inform healthcare providers before any procedures or admissions. This allows the medical team to take appropriate precautions, such as screening and isolation, to protect the patient and others.