Overview
Definition:
Methicillin-resistant Staphylococcus aureus (MRSA) is a bacterium that has developed resistance to many antibiotics
Decolonization refers to the process of eliminating MRSA colonization from the skin and/or mucous membranes, typically nasal passages, to prevent further transmission and infection.
Epidemiology:
Pediatric populations, particularly those in healthcare settings, childcare, or with frequent hospitalizations, are at increased risk for MRSA colonization
Rates of MRSA colonization vary geographically and by setting, with community-acquired MRSA (CA-MRSA) becoming increasingly prevalent.
Clinical Significance:
MRSA colonization is a significant risk factor for subsequent MRSA infection in both the colonized individual and their contacts
Decolonization strategies are crucial for preventing outbreaks in healthcare facilities, reducing community transmission, and protecting vulnerable pediatric patients, especially those with compromised immune systems or underlying skin conditions.
Comparing Strategies
Mupirocin Therapy:
Mupirocin is a topical antibiotic effective against S
aureus
Intranasal mupirocin is a standard treatment for nasal MRSA colonization
Typically applied twice daily for 5-7 days
Resistance can develop with prolonged or inappropriate use.
Bleach Baths:
Dilute bleach baths (using sodium hypochlorite) are an adjunct or alternative strategy for skin decolonization
The dilution is critical: typically 1/4 cup of household bleach (e.g., 6% sodium hypochlorite) per 40 gallons of water
Used for 10-15 minutes, 2-3 times per week
Primarily targets skin colonization.
Evidence Base:
Several studies have evaluated the efficacy of both mupirocin and bleach baths, often in combination with antiseptic washes
Mupirocin is generally considered the first-line treatment for nasal carriage
Bleach baths show efficacy for skin decolonization and may reduce overall MRSA burden, especially in patients with widespread skin colonization
Evidence for their use as a sole decolonization strategy for widespread carriage or in specific pediatric populations is still evolving.
Adverse Effects:
Mupirocin can cause local irritation, burning, or itching
Bleach baths can lead to skin dryness, irritation, or contact dermatitis, especially with incorrect dilution or prolonged contact
Eye and mucous membrane irritation are also possible
Careful monitoring for adverse effects is necessary.
Pediatric Considerations
Age Appropriateness:
Mupirocin is generally safe for use in pediatric patients, with appropriate age-based dosing and application techniques
Dilute bleach baths can be used in infants and children, but extreme caution is advised regarding dilution and preventing ingestion or contact with eyes/mucous membranes.
Compliance:
Ensuring compliance with treatment regimens can be challenging in pediatric patients
Simplified protocols, parental education, and making treatments more palatable (e.g., in bath time) can improve adherence.
Specific Populations:
Children with atopic dermatitis or other chronic skin conditions may benefit from skin decolonization but require careful monitoring for exacerbation of their skin issues
Immunocompromised children require aggressive decolonization strategies to minimize infection risk.
Diagnostic Approach
Screening:
Screening for MRSA colonization is typically performed using nasal swabs, but can also include other sites (e.g., wounds, perineum) depending on the clinical context.
Culture And Sensitivity:
Laboratory confirmation of MRSA colonization involves culture of swabs followed by identification and susceptibility testing
This is essential to confirm MRSA and guide treatment decisions.
Risk Stratification:
Identifying individuals at high risk for colonization or subsequent infection (e.g., recent hospitalization, close contact with MRSA, presence of invasive devices) is crucial for guiding screening and decolonization efforts.
Management Protocols
Nasal Decolonization:
First-line: Intranasal mupirocin ointment (e.g., 2% w/w) applied to anterior nares twice daily for 5-7 days
Second-line or adjunctive: Chlorhexidine washes may be considered
Nasal saline rinses can also help remove colonized bacteria.
Skin Decolonization:
Adjunctive: Daily bathing with antiseptic solutions like chlorhexidine gluconate (CHG) or dilute bleach baths (1:40 dilution of household bleach)
Focus on thorough skin cleansing, especially in intertriginous areas.
Environmental Decontamination:
Concurrent environmental cleaning and disinfection of high-touch surfaces is essential, especially in healthcare settings or households with an infected/colonized individual.
Follow Up:
Repeat screening for MRSA colonization may be recommended after a course of decolonization to confirm eradication
Frequency depends on risk factors and setting.
Key Points
Exam Focus:
Understand the indications for decolonization, the specific agents (mupirocin, bleach), their mechanisms, dosing, duration, and limitations
Be prepared to discuss evidence for efficacy and adverse effects in pediatric patients.
Clinical Pearls:
Always emphasize correct dilution for bleach baths to avoid skin irritation
Mupirocin resistance is a growing concern
use judiciously
Consider patient compliance and education as critical factors for successful decolonization.
Common Mistakes:
Overestimating the efficacy of a single agent for widespread colonization
Incorrectly diluting bleach baths
Not considering concurrent environmental decontamination
Failing to screen or decolonize contacts in outbreak situations.