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Infectious Disease Update 2011

Infectious Disease Update 2011. Jonathan V Iralu, MD, FACP Navajo Area Indian Health Service Infectious Disease Consultant. Case Presentation.

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Infectious Disease Update 2011

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  1. Infectious Disease Update 2011 Jonathan V Iralu, MD, FACP Navajo Area Indian Health Service Infectious Disease Consultant

  2. Case Presentation • A 19 year-old native American man came to an outside clinic with a large abscess on the left shin. The abscess is drained and he is sent home with cephalexin. He returns 5 days later to see you in clinic with an extensive leg cellulitis and a fistula into the abscess cavity. Cultures from the original outside clinic visit are growing MRSA.

  3. CA-MRSA Microbiology • Community acquired MRSA (CA-MRSA) isolates • Are susceptible to many oral antibiotics (except beta-lactams) • Carry type IV staphyloccal chromosomal cassette mec gene (transferable by phage) • Produce certain toxins: Pantone-Valentine Leukocidin and enterotoxins

  4. MRSA Epidemiology • 0.4% of Americans carry PFGE-type US-300 strain of MRSA • Recent surveys show up to 64% of community acquired Staph aureus are methcillin resistant.

  5. Recent MRSA Outbreaks • College football team (Connecticut): 10 out of 100 team members. • linked to turf burns, position (cornerbacks and wide receivers), hot tubs & cosmetic body shaving. • Soldiers in Ft Sam Houston, TX • 3% colonized with MRSA: 38% got STI • 28% colonized with MSSA: 3% got STI

  6. Recent MRSA Outbreaks • California Jails • MRSA prevalence in inmate Staph isolates rose from 29% in 1997 to 74% in 2002 • Minnesota 1996-1998 • 354 patients had MRSA [median age 16] • 84% received inappropriate antibiotics • 90% of isolates sensitive to all antibiotics except beta-lactams.

  7. CA-MRSA Risk Factors • The 4 C’s • contact • contaminated surfaces • crowding • cleanliness

  8. CA-MRSA Clinical Manifestations • Skin infections: • furunculosis, folliculitis, impetigo, abscesses • Necrotizing Pneumonia • fever, neutropenia, effusions, shock • Osteomyelitis • Septic arthritis • Endocarditis

  9. CA-MRSA TreatmentIDSA Recommendations • Cutaneous Abscess • Incision and drainage is the primary treatment • Antibiotics are indicated for • Severe/Extensive disease • Rapid progression of cellulitis • Signs of systemic disease • Co-morbidities/immunosuppression • Extremes of age • Site hard to drain (face, hands, genitalia) • Phlebitis

  10. CA-MRSA TreatmentIDSA Recommendations • Outpatient with purulent Cellulitis: • Empiric therapy for CA-MRSA recommended • Beta-streptococcal therapy is not needed • 5-10 days should suffice • Antibiotics of choice: • Clindamycin • TMP/Sulfa • Doxycycline or minocycline • Linezolid

  11. CA-MRSA TreatmentIDSA Recommendations • Outpatient with non purulent cellulitis: • Defined as cellulitis with no purulent drainage and no abscess • Treat with empirically for Beta Streptococci with a beta lactam antibiotic • Empirically treat for MRSA if patient fails beta lactam therapy or has systemic toxicity • Treat 5-10 days

  12. CA-MRSA TreatmentIDSA Recommendations • To cover both CA-MRSA and Beta Strep, use: • Clindamycin alone • TMP/SMZ plus Amoxicillin • Linezolid alone • Rifampin is not recommended anymore for SSTI

  13. CA-MRSA TreatmentIDSA Recommendations • Hospitalized patients with complicated SSTI • Defined as deeper soft tissue infections, surgical/traumatic wounds, major abscesses, cellulitis and burns • Treat with the following antibiotics • Vancomycin 15 mg/kg IV q 12h • Linezolid 600 mg IV or PO q12h • Daptomycin 4 mg/kg IV daily • Televancin 10 mg/kg IV daily • Clindamycin 600 mg IV or PO TID

  14. CA-MRSA TreatmentIDSA Recommendations • Beta lactam therapy can still be used for hospitalized non-purulent cellulitis cases initially (modify therapy if no response) • 7-14 days of Rx are recommended

  15. CA-MRSA TreatmentIDSA Recommendations • Other Measures: • Keep wounds dry and dressed • Maintain personal hygiene • Avoid sharing personal items (towels, razors, etc) • Cleanse environmental surfaces with cleansers • Consider decontamination if recurrent: • Mupirocin bid to nares and chlorhexidine baths for 5-10 days • Oral antibiotics not recommended

  16. Case Presentation • A 69 year-old diabetic patient is admitted with acute diverticulitis. She is taken to the operating room and ends up in the ICU with septic shock. A CVL is placed in the right IJ position. Three days post-op she develops a fever of 103 degrees F and is found to have MRSA growing in 2 sets of blood cultures. Vancomycin is begun and she immediately defervesces. Blood cultures obtained 48 hours later are subsequently negative.

  17. CA-MRSA TreatmentIDSA Recommendations • Uncomplicated bacteremia • positive blood cultures • Endocarditis excluded • No implanted protheses • f/u blood cultures at 2-4 days negative • Defeversce in 72 hrs • Treat for at least 2 weeks: • Vancomycin 15 mg/kg IV q 12 hrs • Daptomycin 6 mg/kg daily

  18. Modified Duke Criteria • Major: • Two blood cultures grow typical organism with no other focus apparent • Microorganisms c/w IE grow persistently: 2 positive > 12 hours apart or 3 of > 4 positive 1 hour apart. • ECHO: oscillating intracardiac mass

  19. Modified Duke Criteria • Minor: • Predisposing heart condition or IDU • Fever > 38 • Vascular phenomena: arterial emboli, septic PE, mycotic aneurysm/bleed, conjunctival bleed, Janeways • Immune phenomena: GN, Osler Nodes, Roth spots,RF • Positive blood culture not meeting the major criteria

  20. Modified Duke Criteria • Definite endocarditis • Clinical: • 2 major criteria or • 1 major plus 3 minor • or 5 minor • Possible Endocarditis: • 1 major plus 1 minor or • 3 minor

  21. CA-MRSA TreatmentIDSA Recommendations • Complicated Bacteremia: • 4-6 weeks of Vancomycin or Daptomycin 6mg/kg/d • May increase Daptomycin dose 8-10mg/kg/day • Endocarditis: • 6 weeks IV Vancomycin or Daptomycin 6 mg/kg /d • May increase Daptomycin dose 8-10mg/kg/day

  22. CA-MRSA TreatmentIDSA Recommendations • Additional endocarditis recommendations: • Gentamicin is not indicated for native valves • Rifampin is not indicated for native valves • ECHO is recommended for all cases (TEE preferred)

  23. CA-MRSA TreatmentIDSA Recommendations • Valve replacement recommended for: • Vegetation > 10mm • One or more embolic events during first 2 weeks • Valvular insufficiency • Decompensated CHF • Perivalvular leak • New heart block • Persistent fever or bacteremia

  24. CA-MRSA TreatmentIDSA Recommendations • Prosthetic Valve Endocarditis Vancomycin IV for 6 weeks plus Rifampin 300 mg po q 8 h for 6 weeks plus Gentamicin 1mg/kg IV q 8h for 2 weeks • Early valve replacement is recommended

  25. MRSA and Central Lines • Use DTP to diagnose: differential time to positivity • Vancomycin and Daptomycin are drugs of choice • Catheter removal is required for MRSA • Antibiotic lock Rx only if no alternative sites

  26. MRSA and Central Lines • You can treat for 14 days if…. • Not diabetic • No steroids, immunosuppression, or neutropenia • You removed the catheter • No intravascular hardware present • No endocarditis/vascular infection on TEE or U/S • Fever and bacteremia gone at 72 hours • No sign of metastatic infection

  27. Case Presentation • A 49 year-old Native American woman presents to her physician with a flu like illness during January. She is treated with oseltamivir and defervesces. Three days later she develops severe cough with shortness of breath and CP. A CXR shows multilobar pneumonia with left sided empyema. She is admitted to the ICU.

  28. CA-MRSA TreatmentIDSA Recommendations MRSA pneumonia: • Vancomycin or Linezolid are recommended A-II • Clindamycin is also recommended BIII • Treat for 2-21 days • Place chest tube if empyema is present

  29. CA-MRSA TreatmentIDSA Recommendations • MRSA Osteomyelitis: • MRI with gadolinium is the best imaging study • Surgical debridement is mandatory • Vancomycin or Daptomycin 6 mg/kg/d are first choice • TMP/SMZ, linezolid and clindamycin : IV to PO D • Some experts recommend adding rifampin • Treat for 8 weeks minimum; consider PO Rx 1-3 months with Rifampin plus clinda, doxy,T/S, or a FQ • follow ESR or CRP

  30. CA-MRSA TreatmentIDSA Recommendations • Native Joint Septic Arthritis • Always drain or debride the joint • Use the osteomyelitis drugs just listed • Treat 3-4 weeks

  31. CA-MRSA TreatmentIDSA Recommendations • Prosthetic Joint Septic Arthritis • Early Onset (<2 mo), <3 weeks Sx, stable device: • Debride but retain device • 2 weeks of IV Vanco or Dapto plus Rifampin followed by Rifampin plus FQ,T/S, Doxy, or Clindamycin for 3 months for hips and 6 months for knees. • Late Onset > 2 months, >3 weeks Sx, Unstable • Debride and remove device if feasible • Same antibiotics

  32. CA-MRSA TreatmentIDSA Recommendations • CNS Infections: • Meningitis: Vancomycin for 2 weeks • Linezolid or high dose TMP/Sulfa are alternates • Brain Abscess, Subdural empyema, Epidural abscess • I and D Abscess • Vancomycin 4-6 weeks is recommended

  33. CA-MRSA TreatmentIDSA Recommendations • Vancomycin treatment notes: • 15-20 mg/kg IV q 8-12 hours • If septic, give 25-30 mg/kg loading dose • Check troughs with the 4th to 5th dose (no peak) • Aim for trough 15-20 if seriously ill

  34. Ceftaroline • Binds to PBP-2, the MecA gene product of MRSA • Dosed at 600 mg IV q 12 hours • Side Effects: rash,pruritus. No nephro/hepatic SE • CANVAS trials: equivalent to Vanco/Aztreonam for soft tissue infection • FOCUS trials: equivalent to Ceftriaxone for CAP when combined with clarithromycin

  35. Case Presentation • A 34 year old woman comes in to the clinic complaining of dysuria , urinary urgency and frequency for 2 days. She appears well and has normal vital signs. The rest of the physical exam is normal. What is the best treatment for this patient?

  36. Uncomplicated Cystitis in Women • IDSA definition of uncomplicated cystitis: • Absence of: • Fever • Flank pain • Any suspicion of pyelonephritis • Able to take oral medication

  37. Uncomplicated Cystitis in Women • Drug of Choice for Cystitis: • Nitrofurantoin 100 mg po bid for 5 days • Alternate treatments: • TMP/SMZ DS 1 po bid X 3 days (if R < 20%) • Fosfomycin 3 gm po x 1 (lower efficacy) • Pivmenocillin 400mg po bid X 5 days (not in USA)

  38. Quinolones for cystitis? • Quinolones are highly effective for cystitis as shown in 12 randomized trials. • “Propensity for collateral damage” • Quinolone resistance outside the urinary tract • Linked to increased rates of MRSA and resistant pseudomonas • Quinolones OK only if the other drugs are not indicated

  39. Case Presentation continued • The patient never picked up her Nitrofurantoin prescription and now presents 5 days later with vomiting, flank pain and fever to 102.6 degrees F. She has tachycardia, flank pain and 79 WBC on urinalysis. You send urine and blood cultures. What is the treatment of choice now?

  40. Pyelonephritis • Outpatient Therapy: • Ciprofloxacin 500 mg po bid for 7 days (first dose IV) if Quinolone resistance is less than 10% in community • Give a single IV dose of an aminoglycoside or Ceftriaxone if quinolone resistance is >10% • TMP/Sulfa for 14 days is a good alternative

  41. Pyelonephritis and Beta Lactam ABX • Oral beta-lactam antibiotics are less effective than ciprofloxacin and TMP/Sulfa for pyelonephritis • Always give ceftriaxone or a single loading dose of gentamicin if beta-lactams are chosen.

  42. Pyelonephritis in Inpatients • Options: • Fluoroquinolone • Aminoglycoside +/- Ampicillin • Extended spectrum Penicillin or Cephalosporin +/- aminoglycoside • Carbapenem Decision is based on the local sensitivity patterns

  43. 2005 IDSA Asymptomatic bacteriuriaSummary • If not pregnant, ignore asymptomatic bacteriuria

  44. Case Presentation • A 43 year old man was seen 3 weeks ago for a URI and was given doxycycline in the urgent care clinic. Today he has 3 days of bloody diarrhea and cramps. On exam he has a fever of 102 degrees F, BP 90/54 and a tender abdomen. Lab evaluation reveals a WBC of 23K and pre-renal azotemia.

  45. Clostridium difficile • Anerobic GNR acquired by spores in the environment • Responsible for 15-25% of nosocomial antibiotic-associated diarrhea.

  46. C diff Clinical Manifestations • 50% of colonized hospitalized patients are asymptomatic . • 96% of cases have had Abx within the last 14 days and 100% have had Abx within the last 3 months

  47. Hypervirulent strain • Appeared in Quebec in early 2000’s • Called BI/NAP1/027 • Has a mutated Toxin C that is inactive • Produces toxin A and B levels 16 and 23 times higher than other strains • Resistant to fluoroquinolones

  48. C diff Clinical Manifestations • Cardinal symptoms include: • Fever • Cramps • Abdominal pain • Diarrhea • Bacteremia and septic arthritis are rare complications • Ileitis/Pouchitis post colectomy are rare

  49. C diff Clinical Manifestations • Severe manifestations: • Dehydration • Electrolyte disturbance • Hypoalbuminemia • Toxic megacolon • Perforation • AKF • Shock/SIRS

  50. C diff Diagnosis • Only test diarrhea • Only test symptomatic patients

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