|| Methicillin-Resistant Staph Aureous (MRSA)
- synonyms: staph, Staphylococcus aureus, staph aureus, MRSA
- may be hospital acquired (HA) or community associated (CA).
- infections include skin, osteomyelitis, septic arthritis, endocarditis, meningitis, pneumonia
- can be spread by direct contact, towels, sheets, wound dressings, clothes, workout areas, sports equipment, whirlpools
- MRSA most often affects elbows and knees
- Often appears as large, tender, aggresive pustule with an erythematous ring
- Associated with contact sports: football, wrestling, rugby. Often develops from simple abrasions.
- Risk factors: artificial turf, skin abrasion, shaving of skin, sharing towels or equipement, high body mass index, improperly cleaned team whirlpools.
- Diagnosed by wound culture with antibiotic susceptibilities
- Treatment = Incision and drainage and antibiotics
- Empiric Treatment: Bactrim DS 1tab PO BID (8-12mg TMP/40-60SMX per kg/day divided BID for Peds); Doxyxycline 100mg PO BID(do not use in peds); Clindamycin 300-450mg PO QID (10-20mg/kg/day divided QID for PEDS); consider adding rifampin.
- Definitive antiobiotic treatment should be based on culture susceptibilities, consider Infectious disease consultation when available.
- HA-MRSA first line antibiotics: Vancomycin, consider gentamicin or rifampin for synergy. Other agents = daptomycin, linexolid, tigecycline, bactrim.
- CA-MRSA first line antibiotics: doxycycline or clindamycin, or bactrim.
- MRSA Prevention: no equipement sharing between players, no sharing towels, routine cleaning of all whirlpools / shared resources, athletes should pre-scrub with chlorhexidine soaps prior to whirlpool use, all open wounds should be occlusively dressed during practice and games,
- MRSA Osteomyelitis in Children: 4 independent predictors (temperature > 38.0 C, white blood-cell count > 12000 cells/µL, hematocrit < 34%, and C-reactive protein > 13 mg/L) can differentiate between MRSA and MSSA osteomyelitis. The predicted probability of MRSA osteomyelitis is 92% if all 4 predictors are present, 45% if 3 are present, 10% if 2 are present, 1% if 1 predictor is present. (Ju KL, J Bone Joint Surg Am. 2011 Sep 21;93(18):1693-701).
Preoperative screening for MRSA (MRSA Screening)
- nasal cultures may be performed by swabbing a sterile saline solution-moistened polyester (Dacron) swab for 5 seconds along the interior naris.
- 22.6% of patients are MSSA carriers; 4.4% are MRSA carriers. (Kim DH, JBJS 2010;92:1820)
- MRSA & MSSA decolinization = intranasal 2% mupirocin ointment (Bactroban) applied to the interior of each naris twice daily for 5 days and shower wash with 2% clorhexidine daily for 5 days.
-eradication may reduce infection rates from 0.45% without eradication to 0.19% with eradication. (Kim DH, JBJS 2010;92:1820)
- If MRSA carrier, vancomycin used as perioperative prophylactic antibiotic. Vancomycin 15mg/kg started in holding and completed prior to beginning of procedure, with cefazolin 2 or 3 grams at time of “time-out”.
- MRSA carriers (anterior nares) are 2-9 times more likely to develop surgical site infections than noncarriers
- Consider pre-op for: immunocompromised, recent nursing home/hospital admission, antibiotic exposure within 1 yr.
- Options: Chorhexicine 2% topical wash QD for 3-7 days: Doxycycline 100mg PO BID x 7 days: Mupirocin 1cm applied to nares TID for 5-7 days: Providone-Iodine 5% 4x per day for 5 days: Rifampin 300mg PO BID x7days.
- Larkin S, Orthopedics 2008;31:37
MRSA Return to Play - Sports
- Athletes can return to contact sports when no new lesions develop for 48 hours and they have been treated with antibiotics for 72 hours. (OKU-11)
- All wounds must be covered with bioocclusive prewrap and tape.
Kirkland EB, Adams BB. Methicillin-resistant Staphylococcus aureus and athletes. J Am Acad Dermatol. 2008 Sep;59(3):494-502.
Rihn JA, Michaels MG, Harner CD. Community-acquired methicillin-resistant staphylococcus aureus: an emerging problem in the athletic population. Am J Sports Med. 2005 Dec;33(12):1924-9.