Septic Bursitis and Community Acquired MRSA

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					 Septic Bursitis and
Community Acquired
       MRSA
      AM Report
        9/21/07
    Laura Patel, M.D.
         Septic Bursitis: Defined
   Small fluid-filled sac located at the point
    where a muscle or tendon slides across bone.
   Bursae serve to reduce friction between the
    two moving surfaces. There are >150 bursae in
    the body.
   Superficial: subcutaneous and separate skin
    from deeper tissues
   Deep: reduce friction between fibrous
    structures such as tendons from adjacent bone.
       Common locations for Septic
               bursitis
   Superficial bursa: predisposed to infection from skin
    trauma. Direct inoculation vs spread from cellulitus
   Olecranon bursitis: often from repetitive trauma.
    Plumbers, carpenters, COPD, chronic HD via access
    in arm.
   Prepatellar bursitis: often seen in people who kneel a
    lot- housemaids, gardners, clergy.
   Ischiogluteal bursitis: often in spinal cord injured
    patients.
   Deep Bursa: more often associated with septic
    arthritis from hematogenous seeding
Anatomy
                Host Factors
   RA or gout: increase bursal fluid
   Loss of skin integrity
   Impaired response to infection: e.g DM, etoh
             Clinical Presentation:
   History and Physical
       pain and peribursal
        erythema, edema
       Majority have fever
       Joint motion is relatively
        preserved vs septic joint
        where motion is usually
        severely limited.
                              Diagnosis:
   Labs: Elevated wbc with
    neutrophilic predominance.
    Usually are not bacteremic.
   Aspiration of bursal fluid:
        cell count usually >2000 wbc
        Gram stain and culture
        Send for crystals
   Micro: Usually staph aureus
    >80% or Beta hemolytic strep.
    Subacute bursitis more often
    brucella, mycobacteria or fungal.
   Plain film to evaluate for foreign
    body if trauma
   If septic bursitis of deep bursa is
    suspected then ultrasound, CT or
    MRI.
          Differential diagnosis
   Cellulitus
   Crystal induced bursitus
   Acute monoarthritis
   Hemobursa
   Nonseptic bursitis
                         Treatment
   Drain infected bursa either by serial needle aspiration,
    I&D, or in extreme cases bursectomy
   Antibiotics:
       Mild inflammation and not immunosuppressed:
        dicloxicillin or clindamycin, +/- bactrim if high rates of
        MRSA (multiple contacts with hospital, long term care,
        IVDA, community with prevalence >15%)
       Severe inflammation: Vancomycin
       Immunosuppressed: broad spectrum including
        pseudomonal coverage
           Duration of Therapy
   Based on clinical response, culture results and
    health of host
   Most treated 2-3 weeks
     Community Acquired MRSA
   MRSA- initially described in the 1960s in association
    with nosocomial infections
   CA-MRSA- first reported in 1980s. Increasing in
    incidence and prevalence
       NEJM 2006 Prospective study: examined adults with skin
        and soft tissue infections who presented to 1 of 11
        university affiliated ED in US. S. Aureus isolated from 320
        of 422 (76%). Of these, 59% were MRSA and 98% of
        these were CaMRSA
       Some closed communities thought to have higher
        prevalence, up to 40%: Native Americans, daycare, MSM,
        prison inmates, competitive athletes.
     So what’s the difference between
       HA-MRSA and CA-MRSA?
Strain    SCCmec         Antibiotic     PFGE      Toxins   PVL      Infection
          gene           resistance     type               genes    spectrum



HA-MRSA   Types I, II,   Multidrug      USA 100   Fewer    Rare     Bloodstream,
          III            resistant                                  respiratory
                                                                    tract, UTI


CA-MRSA   Types IV, V    Resistance     USA 300   More     Common   Commonly:
                         limited to                                 skin and soft
                         beta-lactams                               tissue
                         and                                        Occasionally:
                         erythromycin                               necrotizing
                                                                    fasciits,
                                                                    necrotizing
                                                                    pneumonia
      Clinical Characteristics of CA-
                 MRSA
   Diagnosis made in outpatient setting
   No medical history of MRSA infection or
    colonization
   No recent history of hospitalization, surgery, dialysis
    or SNF
   No permanent indwelling catheter
   Often associated with skin and soft tissue infections
   CA-MRSA often sensitive to clindamycin, bactrim,
    doxycycline etc.
    CA-MRSA is crossing borders
   More CA-MRSA strains found in hospitalized
    patients
       2003 metaanalysis: found to account for 37% of
        MRSA isolates in hospitalized patients. But
        majority of these patients had >1 healthcare
        associated risk
       Migration of resistant strains from community into
        hospitals may lead to failure of traditional control
        measures
                    Conclusion
   Septic bursitis- more common in superficial bursa
   Associated with erythema, edema and pain, but joint
    motion preserved
   Confirm diagnosis with aspiration and culture of fluid
   Majority caused by S.Aureus
   CA-MRSA is on the rise- think about this when
    choosing antibiotics
   Treatment involves debridement and antibiotics
                            References:
   File, TM. Impact of community-acquired methicillin-resistant Staphylococcus
    aureus in the hospital setting. Cleveland Clinic Journal of Medicine. Vol 74,
    Supplement 4. Aug 2007 S6-11.
   Kluytmans-Vandenberg MF. Community-acquired methicillin-resistant
    Staphylococcus aureus: current perspectives. Clinical Microbiology and Infection,
    Vol 12. Supplement 1, 2006, 9-15.
   Salgado CD, Farr BM, Clafee DP. Community-acquired methicillin-resistant
    Staphylococcus aureus: a meta-analysis of prevalence and risk factors. Clin Infect
    Dis 2003; 36: 131-139.
   Shorr, AF. Epidemiology and Economic Impact of Meticillin-Resistant
    Staphylococcus Aureus. Pharmacoeconomics 2007: 25 (9) 751-768.
   Uptodate: septic bursitis
   Uptodate: Epidemiology and clinical manifestations of methicillin-resistant
    Staphylococcus aureus infection in adults.