Clinical Challenges Community Acquired Methicillin Resistant Staph. Aureus Infections Jose R. Jimenez M.D. Eglin AFB, Florida

Emerging Pathogen Increasing incidence over last 10 yr. 107 million ED visits/yr (cut. Abcess) Frequent reason for treatment failure, patient dissatisfaction. Suspected significant numbers of CA-MRSA carriers in community, among us.

Hospital vs. Community Acquired MRSA Different sensitivities Hospital-acquired MRSA generally resistant to multiple drugs, frequently leading to the use of parenteral vancomycin CA-MRSA resistant to penicillin and cephalosporins, but sensitive to other oral antibiotics, such as clindamycin, TCN, TMP/SMX CA-MRSA usually sensitive to oral rifampin. Due to rapidly developing resistance to rifampin, the drug must be used in combination with another antibiotic.

Hospital vs. Community Acquired MRSA CA-MRSA produces cytotoxins (Panton-Valentine leukocidin) associated with tissue necrosis. This cytotoxin is not usually found in HA-MRSA.

Initial clinic evaluation: History Onset, duration, severity Prior episodes Exposure: Home, work, gym, playground, participation in organized sports (wrestling, football, fencing, etc.), hot tub use. ROS: Associated symptoms PMH Medications,allergies

Initial clinic evaluation: History Soc. Hx.: Tobacco, ETOH, drug use. Try to elicit any factors that would classify the patient as a compromised host, and/or a special exposure situation.

Initial clinic evaluation: Physical Examination General examination Skin: lesion, number, size, location, palpation (fluctuant,creppitus, F.B.), ulceration, necrosis, streaking. Lymph nodes palpable

Physical Examination: Adjunct Modalities Mainly to rule out f.b. Radiographs CT Ultrasound Fluoroscopy MRI

Therapeutic Decisions: Lesion Management I & D ? Lesion exploration/ F. B. removal Lesion C & S Pack the wound or not, what to use. Informed Consent/ Permit signed

Therapeutic Decisions: Medication Selection Antibiotic Analgesic

Antibiotic Selection Age <7 yr avoid TCN Age <18 yr avoid Quinolones Cost/ Patient resources Patient compliance Facility/ Community resources available

Antibiotic Selection, Outpatient Management None Penicillin and derivatives Augmentin cephalosporin Minocycline, Doxycicline TMP/SMX Clindamycin Fluoroquinolones Zyvox

Antibiotic Selection, Inpatient or Home Health Management Parenteral: Vancomycin, Synercid, Zyvox, Cubicin

Patient Disposition/ Education Wound care Medication Follow up/ reexamination Earlier reexamination if there is no improvement, or if new symptoms develop Make sure patient understands you are treating empirically, that there is a possibility of treatment failure, what to do.

MRSA Carrier Management Carried in skin, most frequently in the anterior nasal passages Recommendation: mupirocin topically to the nasal passages, antibacterial body wash with chlorhexidine

CA- MRSA Additional Control Measures Contact Sports with frequently used protective gear: football, wrestling, fencing Gear to be washed ideally after every use, at least weekly. Exercise equipment pads to be cleaned and disinfected regularly

CA- MRSA Additional Control Measures Health Care Personnel: MUST FOLLOW INFECTION CONTROL MEASURES

REFERENCES Sanford guide to antimicrobial selection Tintinalli: Review in Emergency Medicine