Big Bad Bugs in the Dialysis Unit
Douglas Shemin, MD
Kidney Diseases and Hypertension Division, Rhode Island Hospital
Big Bad Bugs
1. MRSA2. VRE3. C. diff
Microbiology: study of microscopic living organisms
AlgaeProtozoansFungiVirusesBacteria: one cell structure, have
cell walls
5,000,000,000,000,000,000, 000,000,000,000 bacteria in the world!
cocci rods
Gram staining of bacteria
Gram positive Gram negative
Classification of bacteria
• Gram positive cocci
• staphylococcus• streptococcus• enterococcus
• Gram positive rods
• clostridia
• Gram negative cocci
• Neisseria gonorrhea
• Gram negative rods
• Pseudomonas• E. coli• Vibrio cholera
Staphylococcus
Colonize skin and soft tissueStaph 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 > 7085 % cases in patients with cathetersIn hospital death rate with invasive MRSA:
17 %
Treatment of MRSA
Vancomycin historically agent of choice
Newer agents: linezolid, daptomycinBut: 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 cocciNormally reside in gastrointestinal tract
(feces, mouth and pharynx) and vaginaHistorically susceptible to vancomycin;
VRE (vancomycin resistant enterococcus) reported in 1989
VRE
Found in stoolRisk 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)
Treatment of VRE
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 rodUsually associated with membrane
formation in colon (pseudomembranous colitis)
Clinical manifestation: diarrheaAlways associated with previous use of
antibioticsDiagnosed by c. difficile toxin in stool
Pseudomembranous colitis due to c.diff infection
Pathogenesis of c. diff
1. Use of antibiotics that alter the intestinal flora in the colon
2. Age or illness related susceptibility: geriatrics, immunosuppression, poor nutrition
Symptoms of c. diff infection
1. Fever, abdominal pain and diarrhea soon after treatment of an infection with an antibiotic
2. Toxic megacolon can occur, with colonic perforation
Treatment of c.diff
1. Prevention: avoidance of unnecessary antibiotics
2. Stopping antibiotic once diagnosis made
3. Oral vancomycin or metronidazole (Flagyl)
4. No anti-diarrheal agents5. Lactobacillus tablets may be helpful
Big Bad Bugs: MRSA, VRE, c. diff
1. All associated with immunodeficiency, chronic illness, and chronic kidney disease
2. All associated with antibiotic use3. 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?
1. Protect yourself: cooperating with isolation and gowning/gloving procedures
2. Educate your patients: isolation techniques decrease trasnmission
3. Educate patients and families: antibiotics can have significant negative consequences
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