Outpatient and Inpatient MRSA:
the New IDSA Guidelines
Presented by Susan Kline, MD, MPH
University of Minnesota Medical School
Department of Medicine
Division of Infectious Diseases
Minneapolis , MN
Presented to: Burnett Medical Center staff ,
Grantsburg, WI
Jan. 19, 2012
Disclosure Slide
I have served as a member of the
Speakers Bureau and have received
honoraria and research support from
Pfizer Pharmaceuticals
Objectives
Review the new MRSA treatment
guidelines
Focus on adults
Focus on common clinical conditions
– Skin and soft tissue infections
– Bacteremia and endocarditis
– Pneumonia, community and hospital acquired
2011 Clinical Practice Guidelines by the
Infectious Diseases Society of America: for the treatment
of MRSA infections in Adults and Pediatrics
Clinical Topics
1.Skin and soft tissue infections
2.Recurrent skin and soft tissue infections
3.MRSA bacteremia and endocarditis
4.MRSA pneumonia
5.MRSA bone and joint infections
6.MRSA central nervous system infections
7.Role of combination or adjunctive therapies
8.Vancomycin dosing and monitoring
9.Vancomycin susceptibility testing
10.Management of persistent bacteremia and vancomycin treatment failures
11.MRSA neonatal infections
Clinical Infectious Diseases 2011:52;1-38.
Evidence Grading System
Strength of recommendation
A Good evidence to support a recommendation for or against
use
B Moderate evidence to support a recommendation for or
against use
C Poor evidence to support a recommendation
Quality of evidence
I Evidence from >= 1 properly randomized, controlled trial
II Evidence from >= 1 well-designed clinical trial, without
randomization; from cohort or case-controlled analytic studies
(preferably from > 1 center); from multiple time-series; or from
dramatic results from uncontrolled experiments
III Evidence from opinions of respected authorities; based on
clinical experience, descriptive studies, or reports of expert
committees.
What is the management of skin and soft tissue
infections (SSTIs) in the era of community associated
MRSA (CA-MRSA) ?
For cutaneous abscess incision and
drainage (I &D) is the primary treatment
(A-II)
For simple abscess I &D alone should be
adequate
Additional data needed to determine role
of antibiotics, if any
Antibiotic therapy recommended
In addition to I & D for
– Severe abscesses
– Multiple abscesses
– Rapid progression with cellulitis
– Signs or symptoms of systemic illness
Send culture to guide antibiotic therapy if
needed
Antibiotic therapy recommended
In addition to I & D for
– Co-morbidities or immunosuppression
– Extremes of age
– Difficult to drain abscess site (face, hand,
genital)
– Septic phlebitis
– Lack of response to I & D alone (A-III)
For Outpatients with purulent cellulitis
Send culture
Empiric therapy for CA-MRSA
5-10+ days (follow patient response)
Empiric therapy for Beta-hemolytic
streptococcus likely not needed (A-II)
For outpatients with non-purulent
cellulitis (no purulent exudate, pus or abscess)
Empiric therapy for beta hemolytic strep
recommended
Role of CA-MRSA unknown
Add CA-MRSA coverage if
– No response to strep treatment –or– Systemic toxicity
Treat for 5-10+ days, need to follow
patient response
Treatment options for CA-MRSA
outpatient empiric therapy
Drug
Adult Dose
TMP-SMX 1-2 DS BID
Doxycycline or
Minocycline 100 BID
Clindamycin 300-450 TID
Linezolid
600 BID AII
Evidence Grade
AII
AII
AII
For coverage for both beta hemolytic
streptococcus and CA-MRSA
Clindamycin alone (A-II)
OR
TMP/SMX or a tetracycline (doxy or mino)
PLUS
A beta-lactam (i.e.. amoxicillin, cephalexin,
dicloxacillin ) (A-II)
OR
 Linezolid alone (A-II)
32 y/o M with 3 days of an enlarging, painful lesion on his L thigh that he
attributes to a “spider bite”.
T 36.9 BP 118/70 P 82
What is the appropriate
management of this patient?
A. Incision and drainage alone
B. Incision and drainage plus oral antiMRSA antimicrobial agent
C. Oral anti-MRSA antimicrobial agent alone
D. Therapy for Group A streptococcus alone
Treatment of Complicated SSTIs
hospitalized
Deeper soft tissue infections
Surgical/traumatic wound infection
Major abscesses
Cellulitis
Infected ulcers/burn
 Surgical debridement
 Send cultures
 Start empiric therapy for MRSA
Inpatient therapy for complicated
SSTIs (empiric to cover MRSA)
Vancomycin IV 15-20mg/kg/dose q 8-12
hours (A-I)
Linezolid (IV / PO) 600mg q 12 hours (A-I)
Daptomycin 4mg/kg IV q 24 hours (A-I)
Televancin 10mg/kg IV q 24 hours (A-I)
Clindamycin 600mg IV/PO TID (A-III)
Inpatient therapy for non-purulent
cellulits
Could start a beta lactam alone
(e.g. cefazolin)
Then add MRSA coverage if no response
(A-II)
Length of therapy for inpatient
SSTIs
7-14 days + of therapy
Need to individualize based on patient
response
Usually start with IV and don’t switch to
PO until the cellulitis is nearly resolved to
prevent relapse, exception to rule is
linezolid which has excellent oral
absorption nearly 100%
Management of recurrent MRSA
SSTIs
Emphasize good personnel hygiene,
wound care and environmental cleaning
– Regular bathing
– Frequent hand washing, esp. if touch wound
– Keep draining wound covered
– Avoid sharing or reusing razors, linens, towels
– Clean high touch surfaces with commercial
cleaners
Consider decolonization if
Recurrent SSTI despite good wound care,
hygiene and cleaning
Ongoing household transmission
Nasal mupirocin BID x 5-10 days +/Daily chlorhexidine gluconate baths/showers x
5-14 days
Reserve oral antibiotics for active infections
Use oral agent plus rifampin plus topical agents
if have relapse despite doing all of the above
What is the management of MRSA
bacteremia and endocarditis?
Uncomplicated bacteremia
– No prosthesis, lines removed, fevers resolved
in 72 hours, blood cultures negative after 2-4
days, no metastatic focus of infection
– Endocarditis excluded
Echocardiogram recommended, TEE>TTE
Give antibiotics x at least 14 days
– Vancomycin 15-20mg/kg IV q 12 hours (A-II)
– Daptomycin 6mg/kg IV q 24 hours (A-I)
Complicated MRSA bacteremia
4-6 weeks of antibiotics recommended
– Vancomycin 15-20mg/kg IV q 12 hours
– Daptomycin 6mg/kg IV q 24 hours
– Some experts recommend high dose
daptomycin 8-10mg/kg IV q 24 hours (B-III)
Off label dosing
MRSA endocarditis
6 weeks of antibiotics recommended
– Vancomycin 15-20mg/kg IV q 12 hours
– Daptomycin 6mg/kg IV q 24 hours
– Some experts recommend high dose
daptomycin 8-10mg/kg IV q 24 hours (B-III)
Off label dosing
Addition of gentamicin or rifampin not
recommended for native valve endocarditis
Prosthetic valve MRSA
endocarditis treatment (B-II)
Vancomycin IV 15-20mg/kg IV q 8-12
hours x 6 weeks
Plus gentamicin 1mg/kg IV q 8 hours x 2
weeks
Plus rifampin 300mg PO/IV q 8 hours
X 6 weeks
May need early valve replacement surgery
Indications for surgery for MRSA endocarditis
Large vegetations > 1 cm
Occurrence of embolic events during 1st 2 weeks
of therapy
Severe valvular insufficiency
Valve perforation or dehiscence
Decompensated heart failure
Perivalvular or myocardial abscess
New heart block
Persistent fevers or bacteremia
Vancomycin dosing guidance
For serious infections dose based actual
weight
15-20mg/kg IV q 8-12 hours
Trough goal is 15-20 microgram/ml
Need to adjust dosing interval upward for
decreased creatinine clearance
60 year old male presents with 4 days of fevers and
chills
T 38.5 BP 102/71 P 104 R 20 O2 sat 98% RA weight
100 kg
Heart: 2/6 systolic murmur at apex
Chest: CTAB
Skin: no peripheral stigmata of endocarditis
Labs: 15.5> 39 > 350 Cr 0.8
Started on IV vancomycin 1 gram every 12 hours
HD #1 blood cx: 3/4 MRSA (vanco MIC 1)
HD # 5
T 37.8 BP 138/70 P 113 R 16 O2 sat 96% RA
Alert and interactive, no new physical exam
findings
Blood cx: 2/2 MRSA (vanco MIC 1)
Vancomycin trough 7 microgm/mL
2 cm mitral valve vegetation on echocardiogram
What changes to the patient’s
antibiotics should be made?
A. Add gentamicin to vancomycin
B. Add rifampin to vancomycin
C. Increase vancomycin dose to 1.5 gram IV
Q12 hrs, target goal trough of 15-20
microgm/mL
D. Discontinue vancomycin and start IV
daptomycin 6 mg/kg Q24 hrs
Treatment for health care
associated MRSA pneumonia
Vancomycin 15-20mg.kg IV q 8-12 hours
(A-II)
Linezolid 600mg PO/IV q 12 hours (A-II)
Clindamycin 600mg PO/IV TID (B-III)
– If strain susceptible
7-21 day course depends on
severity/extent of infection
Hospitalized patients with severe
community acquired pneumonia (CAP)
Start treatment for MRSA pending sputum
gram stain and culture (AIII)
Severe CAP defined as
– ICU admit
– Necrotizing or cavitary infiltrates
– Empyema (also need drainage)
35 y/o F previously healthy with 4 days of fever, chills, myalgias,
and cough. Now with increasing dyspnea and hemoptysis x 24 hrs
T38.7 P120 BP96/60 R24
89%RA
Moderate respiratory
distress with coarse
rhonchi
WBC 15, Hct 44, Plt 425
Rapid flu: + influenza A
Sputum gram stain/ cx:
pending
Intubated, admitted to
ICU
In addition to starting anti-influenza therapy,
would you treat with antibiotics and if so which?
A. None
B. Ceftriaxone and azithromycin
C. Vancomycin and ceftriaxone and
azithromycin
D. Linezolid and cefepime
E. Daptomycin
MRSA pneumonia
Daptomycin should not be used for Rx of
pneumonia, (inactivated by pulmonary
surfactant)
Empiric Rx for MRSA recommended for
severe CAP (ICU admission, necrotizing
or cavitary infiltrates, or empyema)
Discontinue empiric Rx if cultures do not
grow MRSA
Questions/Discussion
References:
Clinical Practice Guidelines by the Infectious Disease Society of America for the Treatment of MethicillinResistant Staphylococcus aureus Infections in Adults and Children
Panel Members / Authors
Catherine Liu, MD
Henry “Chip” Chambers, MD
Arnold S. Bayer, MD
Sara E. Cosgrove, MD
Robert S. Daum, MD
Scott K. Fridkin, MD
Rachel J. Gorwitz, MD
Sheldon L. Kaplan, MD
A.W. Karchmer, MD
Donald P. Levine, MD
Barbara E. Murray, MD
Michael J. Rybak, PharmD
David A. Talan, MD
SPGC Liaison
Stan Deresinski, M.D.
Published in: Clinical Infectious Diseases Feb. 1, 2011