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8.29.06 Staphlococcal bacteremia

8.29.06 Staphlococcal bacteremia - Staphylococcal...

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Unformatted text preview: Staphylococcal bacteremia Shannon Galvin, M.D. August 2006 Staph bacteremia Staph Overview Clinical syndromes How to treat How Complications Complications GPC in blood Other positive cultures Bacteremia Bacteremia Nosocomial Most common pathogen—Staph epi 2nd Staph aureus—20% of nosocomial bacteremias Risk factors—IV catheters, severe pneumonia, Risk surgical wound, foreign body, dialysis Community acquired Community More likely to have IVDU, epidural abscess Australia 2005 49% of staph bacteremias Australia community onset, 12% of these MRSA community Wisplinghoff et al. Clin Infect Dis. 2004 Aug; 39(3) Coag neg Staph Coag Consider as a pathogen when… 2 or more positive cultures from different or sites sites Clinical findings of infection especially in Clinical immunocompromised patient immunocompromised Similar genotype from different time points Isolated from a sterile site—joint, CSF Isolated especially if prosthetic device present (shunt, artificial joint) (shunt, Staph aureus bacteremia Staph Serious life threatening infection 30% mortality 20% severe metastatic complications Any positive culture for Staph aureus from a Any sterile site must be treated sterile 5147 Staphylococcus aureus MRSA MRSA UNC antibiogram 2004 Staph aureus-57% oxacillin susceptible Nationwide approx 53% ICU, 46% inpatient Nationwide 31% outpatient isolates were MRSA 31% MRSA MRSA Is MRSA more virulent than MSSA? Is Unclear, but patients with MRSA bacteremia tend to have higher morbidity and mortality Efficacy of therapy-vanc inferior to nafcillin/oxacillin nafcillin/oxacillin MSSA relapse 19% vanc vs 0% nafcillin Chang MSSA Medicine 2003 2003 MRSA independent poor prognostic factor in MRSA Staph endocarditis Staph Differences in host populations Community MRSA Community Defined as seen in patients with no health care contact Defined in past year and positive cultures within 48 hours of admission or in outpatient setting admission Seems especially prevalent in military personnel Presents as soft tissue abscess- “bug bite” that can be Presents progressive and associated with bacteremia progressive Always check sensitivities Initially can use trimethoprim-sulfamethoxazole or Clindamycin- however resistance to this is inducible, Clindamycinmake sure a D-test is performed make Vancomycin for serious infections Linezolid also an option 7824 D- test Blunting of the clindamycin susceptibility zone adjacent to the erythromycin zone Clinical syndromes Clinical Catheter associated infections Endocarditis versus Bacteremia Suppurative complications – Vertebral osteomyelitis and discitis – Septic arthritis – Splenic abscess – Meningitis – Deep tissue abscess Complications Complications Patients at highest risk for complications – Absence of identifiable focus – > 3days of positive cultures (OR 5.58) Clinical examination underestimates the Clinical frequency of complications frequency Complications Complications Endocarditis Vertebral osteomyelitis/discitis Septic arthritis Splenic abscess Mycotic aneurysms Meningitis Tissue abscess Risk of endocarditis with Staph bacteremia bacteremia Series of patients with S. aureus Series bacteremia bacteremia – 25% had endocarditis by TEE – 7% by TTE Definite infective endocarditis Definite Pathological criteria Pathological Microorganisms demonstrated by culture or histological examination of a vegetation, a vegetation that has embolized, or an intracardiac abscess specimen; or vegetation, Pathological lesions; vegetation or intracardiac abscess confirmed by histological examination showing active endocarditis examination Clinical criteria Clinical 2 major criteria; or major 1 major criterion and 3 minor criteria; or major 5 minor criteria minor Possible IE Possible 1 major criterion and 1 minor criterion; or major 3 minor criteria minor Rejected Rejected Firm alternative diagnosis explaining evidence of IE; or Firm Resolution of IE syndrome with antibiotic therapy for <4 days; or Resolution No pathological evidence of IE at surgery or autopsy, with antibiotic therapy for <4 days; or days; Does not meet criteria for possible IE as above Does Major criteria Major Blood culture positive for IE Blood Typical microorganisms consistent with IE from 2 separate blood cultures: Viridans streptococci, Streptococcus bovis, HACEK group, Staphylococcus aureus; or Streptococcus HACEK Staphylococcus or community-acquired enterococci in the absence of a primary focus; or community-acquired Microorganisms consistent with IE from persistently positive blood cultures defined as follows: At least 2 positive cultures of blood samples drawn >12 h apart; or all of 3 or a majority of 4 separate cultures of blood (with first and last sample drawn at least 1 h apart) apart) Single positive blood culture for Coxiella burnetii or anti–phase 1 IgG Coxiella antibody titer >1:800 antibody Evidence of endocardial involvement Evidence Echocardiogram positive for IE (TEE recommended for patients with prosthetic valves, rated at least "possible IE" by clinical criteria, or complicated IE [paravalvular abscess]; TTE as first test in other patients) defined as follows: [paravalvular oscillating intracardiac mass on valve or supporting structures, in the path of regurgitant jets, or on implanted material in the absence of an alternative anatomic explanation; or abscess; or new partial dehiscence of prosthetic valve; new valvular regurgitation (worsening or changing or preexisting murmur not sufficient) (worsening Minor criteria Minor Predisposition, predisposing heart condition, or IDU Predisposition, Fever, temperature >38°C Fever, Vascular phenomena, major arterial emboli, septic pulmonary infarcts, mycotic aneurysm, intracranial hemorrhage, conjunctival hemorrhages, and Janeway’s lesions aneurysm, Immunologic phenomena: glomerulonephritis, Osler’s nodes, Roth’s spots, and rheumatoid factor rheumatoid Microbiological evidence: positive blood culture but does not meet a major criterion as noted above* or serological evidence of active infection with organism consistent with IE noted Echocardiographic minor criteria eliminated Echocardiographic TTE vs TEE TTE Catheter associated Staph bacteremiaCatheter estimated probability of endocarditis 3-4% here TTE is cost effective here Unexplained bacteremia-estimated risk of Unexplained endocarditis 4-50% but for Staph probably exceeds 25% here TEE is cost effective exceeds Heidenreich PA et al. Echocardiography in patients with suspected Heidenreich endocarditis: a cost effective analyis Chang FY, MacDonald BB, Peacock JE Jr, Musher DM, Triplett P, Mylotte JM, O'Donnell A, Wagener MM, Yu VL. A prospective multicenter study of Staphylococcus aureus bacteremia: incidence of endocarditis, risk factors for mortality, and clinical impact of methicillin resistance. of Medicine (Baltimore). 2003 Sep;82(5):322-32 Observational study of 505 pts with Staph bacteremia Observational 13% had found to have endocarditis – 21% of community acquired bacteremias, 5% hospital acquired, 12% of 21% dialysis acquired dialysis MRSA pts had more persistent bactermia, MRSA an independent MRSA predictor of death from endocarditis predictor Positive blood cultures at day 3, valvular heart disease, IVDU, Positive community acquired source, or unknown source risks for having endocarditis endocarditis 31% 30 day mortality for endocarditis, 21% others Van Hal SJ, Mathur G, Kelly J, Aronis C, Cranney GB, Jones PD. The role of transthoracic echocardiography in excluding left sided infective endocarditis in Staphylococcus aureus bacteraemia. J Infect. 2005 Oct;51(3):218-21. Staphylococcus Retrospective study of 125/800 pts at a single center who had both TTE and TEE. center Negative likelihood ratio 0.33 for endocarditis Negative with normal TTE with Endocarditis by TEE was found in less than 2% Endocarditis of patients without embolic phenomena with normal (no valvular lesions, and no or trivial regurgitation) echo regurgitation) Management of catheter-related Staphylococcus aureus bacteremia: when may sonographic study be unnecessary? Pigrau C, Rodriguez D, Planes AM, Almirante B, Larrosa N, Ribera E, Gavalda J, Pahissa A. Eur J Clin Microbiol Infect Dis. 2003 Dec;22(12):713-9. 213 episodes of bacteremia were registered and 167 (78.4%) were nosocomial. Among these, 87 (52.1%) were catheter-related Staphylococcus aureus bacteremia and 20 were primary nosocomial bacteremia. Endocarditis was diagnosed during the acute episode in 7/107 of these patients (2 by persistent fever after catheter removal and 5 by metastatic foci; 3 of them also had cardiac risk factors) and confirmed with transesophageal echocardiography. Among the 84/87 catheter-related Staphylococcus aureus bacteremia and 16/20 primary nosocomial bacteremia patients who did not develop endocarditis, 31 patients died during the acute episode (16 due to sepsis despite initiation of antibiotic treatment and 15 due to the underlying disease) and five had osteoarticular foci. 64 episodes were considered to be uncomplicated bacteremia (no cardiac risk factors, persistent fever, metastatic foci, or clinical signs of endocarditis) and were treated with 10-14 days of high-dose antistaphylococcal antibiotics. Echocardiography was not mandatory in these patients. Of the 64 uncomplicated episodes, 62 were followed for at least 3 months and none relapsed or developed endocarditis Complications Complications Endocarditis Vertebral osteomyelitis/discitis Septic arthritis Splenic abscess Mycotic aneurysms Meningitis Tissue abscess Principles of treatment Principles Remove focus-<18% treatment success if focus Remove remains remains Drain fluid collections Replace/remove prosthetic device if possible High risk of endocarditis-need echo TTE for line infections with no embolic TTE stigmata???, TEE for all others vs TEE for all stigmata???, Vertebral osteo/deep soft tissue abscess often Vertebral overlooked-may require imaging overlooked-may Treatment Treatment Simple bacteremia—focus removed, neg echo, Simple normal heart valves, repeat cultures at 3 days negative—14 days negative—14 Complicated-positive blood cultures at 3 days, Complicated-positive continued fevers-consider imaging for osteo/soft tissue focus—treat for 3-4 weeks tissue Endocarditis-treat for 4-6 weeks Osteo/abscess-drain focus treat for 4-8 weeks Daptomycin Daptomycin Daptomycin 6mg/kg daily n=124 vs antiStaph PCN/Vanc Daptomycin plus gent (n=122) plus At 42 days “successful outcome” 44% dapto vs 41% At showing noninferiority showing Failure to reach successful outcome included death, Failure clinical or microbiologic failure, or discontinuation of study drug due to adverse event or failure study Higher rate of microbiologic failure in daptomycin More adverse renal events in standard therapy Reduced susceptibility noted in daptomycin and vanc not Reduced in oxacillin treated subjects in CK elevations in 6% of daptomycin treated subjects Shorr AF, Kunkel MJ, Kollef M. Linezolid versus vancomycin for Staphylococcus aureus bacteraemia: pooled analysis of randomized studies. pooled J Antimicrob Chemother. 2005 Nov;56(5):923-9. Antimicrob Meta-analysis Meta-analysis Clinical cure 14 (56%) of 25 linezolid Clinical recipients and 13 (46%) of 28 vancomycin recipients (OR, 1.47; 95% CI, 0.50-4.34). Microbiological success occurred in 41 (69%) of 59 linezolid recipients and 41 (73%) of 56 vancomycin recipients (OR, 0.83; 95% CI, 0.37-1.87 0.83; Numerous case reports of Staph aureus Numerous developing linezolid resistance on therapy developing Always treat Always Any Staph aureus—blood, CSF, urine, Any most body fluids most Any fungus in blood, CSF GNR in blood ...
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