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Big Bad Bugs in the Dialysis Unit. Douglas Shemin, MD Kidney Diseases and Hypertension Division, Rhode Island Hospital. Big Bad Bugs. MRSA VRE C. diff. Microbiology: study of microscopic living organisms. Algae Protozoans Fungi Viruses Bacteria: one cell structure, have cell walls.
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Big Bad Bugs in the Dialysis Unit Douglas Shemin, MD Kidney Diseases and Hypertension Division, Rhode Island Hospital
Big Bad Bugs • MRSA • VRE • C. diff
Microbiology: study of microscopic living organisms Algae Protozoans Fungi Viruses Bacteria: one cell structure, have cell walls
5,000,000,000,000,000,000, 000,000,000,000 bacteria in the world! rods cocci
Gram staining of bacteria Gram positive Gram negative
Gram positive cocci staphylococcus streptococcus enterococcus Gram positive rods clostridia Gram negative cocci Neisseria gonorrhea Gram negative rods Pseudomonas E. coli Vibrio cholera Classification of bacteria
Staphylococcus Colonize skin and soft tissue Staph epidermidis (coagulase negative) Staph aureus (coagulase positive): 1940s: treated with pencillin 1970s: treated with methicillin 1990s: methicillin resistant (MRSA)
MRSA Introduced into health facilities from endemic areas (nursing homes, hospitals) or by HCWs Rapidly disseminates and colonizes patients (especially with skin diseases or breakdown) and HCWs. Also lives on machinery, environmental surfaces Risk of colonization highest in elderly, in ICU patients, HD patients
MRSA in hemodialysis patients: CDC, 2005 813/5287 invasive MRSA cases in 2005 in HD patients (15 % of the total) 45.2 cases invasive MRSA/1000 dialysis patients: 100 times greater risk 70 % cases in patients > 70 85 % cases in patients with catheters In hospital death rate with invasive MRSA: 17 %
Treatment of MRSA Vancomycin historically agent of choice Newer agents: linezolid, daptomycin But: look out for VRSA (first reported in 2002 in a patient on long term hemodialysis
Control of MRSA Screening for carriage with swabs from nares and skin lesions Isolation techniques—handwashing, gloves, gowns, masks Eradication of the carrier state (with intranasal or topical mupirocin (Bactroban)
Enterococcus Enterococcus are gram positive cocci Normally reside in gastrointestinal tract (feces, mouth and pharynx) and vagina Historically susceptible to vancomycin; VRE (vancomycin resistant enterococcus) reported in 1989
VRE Found in stool Risk factors: chronic illness, kidney failure, long hospital stays, use of antibiotics VRE is resistant to virtually all antibiotics: penicillin, cephalosporins, sulfa, quinolones
Prevention of VRE Avoidance of use of vancomycin (use of cefazolin for treatment of staph infections instead, or waiting for culture results before starting antibiotics)
Control of VRE Screening for carriage with stool cultures Isolation techniques—handwashing, gloves, gowns, designated equipment Stricter isolation with diarrhea or incontinence
Clostridium difficile (c.diff) Gram positive rod Usually associated with membrane formation in colon (pseudomembranous colitis) Clinical manifestation: diarrhea Always associated with previous use of antibiotics Diagnosed by c. difficile toxin in stool
Pathogenesis of c. diff • Use of antibiotics that alter the intestinal flora in the colon • Age or illness related susceptibility: geriatrics, immunosuppression, poor nutrition
Symptoms of c. diff infection • Fever, abdominal pain and diarrhea soon after treatment of an infection with an antibiotic • Toxic megacolon can occur, with colonic perforation
Treatment of c.diff • Prevention: avoidance of unnecessary antibiotics • Stopping antibiotic once diagnosis made • Oral vancomycin or metronidazole (Flagyl) • No anti-diarrheal agents • Lactobacillus tablets may be helpful
Big Bad Bugs: MRSA, VRE, c. diff • All associated with immunodeficiency, chronic illness, and chronic kidney disease • All associated with antibiotic use • Although definitive treatment is with antibiotics, the most effective treatment is prevention, with isolation techniques and handwashing
What can you do to protect your patients? • Protect yourself: cooperating with isolation and gowning/gloving procedures • Educate your patients: isolation techniques decrease trasnmission • Educate patients and families: antibiotics can have significant negative consequences