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