Pocket Oncology (Pocket Notebook Series), 1st Ed.

INFECTION CONTROL

Cesar J. Figueroa and Monika K. Shah

Catheter-related Bloodstream Infection (CRBSI) and Management

• For suspected CRBSI, paired BCx (one each of peripheral vein & catheter) can be drawn PRIOR to antibiotic Rx. Routine cx in the absence of suspected infxn are NOT recommended.

• Diagnostic criteria: Same organism should grow from at least one peripheral BCx & from cx of the catheter tip OR the same organism is cultured from at least two blood samples (one from a catheter hub & the other from a peripheral vein or second lumen).

• DTP or diff. time to positivity refers to growth detected from the catheter sample at least 2 h before growth detected from the peripheral sample.

• Organisms: Most common: Coagulase-negative staphylococcusS. aureus, enteric GNR, Candida spp, & Pseudomonas aeruginosa.

• Management: Vancomycin + empiric gram-negative Rx; based on clinical stability of pt & institutional microbial susceptibility patterns, consider tx of resistant gram-negative organisms w/combination Rx; consider empiric candida Rx for those on TPN, hematologic malignancy or post-transplant & those on prolonged broad spectrum abx.

• Catheter removal: Long-term catheters: W/CRBSI & EITHER sev. sepsis/suppurative thrombophlebitis/NVE/ or BCx + despite 72 h of appropriate Rx OR infxn due to S. aureus, P. aeruginosa, fungi, or Mycobacteria. Short-term catheters: CRBSI due to gram-negative bacilli, S. aureus, enterococci, fungi, & mycobacteria (Clin Infect Dis 2009;49:1).

Clostridium Difficile Infection (CDI) and Management

• Definition: Diarrhea & EITHER stool assay positive OR identification of pseudomembrane by colonoscopy or histopathology

• Epidemiology: 1° pathogen for antibiotic-associated colitis; responsible for 15–25% nosocomial diarrhea; <1% pts will have ileus or toxic megacolon & its complications (Age Ageing 1999;28:107; N Engl J Med2002;346:334; N Engl J Med1994;330:257).

• RF: Advanced age, long duration of hospitalization, exposure to antimicrobial agents; CA chemotherapy & GI manipulations, including surgery.

• Testing: Must be done ONLY on diarrheal stool unless there is presence of ileus. Testing usually detects the presence of toxin produced by the organism.

• Rx: Must d/c abx & avoid use of antiperistaltic agents (Infect Control Hosp Epidemiol 2010;31:431):

• Fidaxomicin has been shown to be non-inferior to Vancomycin for mild-mod. CDI & can be a/w less recurrence (N Engl J Med 2011;364:422).

• Fecal microbiota transplantation: Principle is to restore colonic flora w/intestinal microorganisms from a healthy donor (via infusion of a liquid suspension of stool), being studied mainly for recurrent CDI.

Respiratory Viruses and Management

• Can be important causes of morbidity & mortality, particularly in pts w/hematologic malignancies. Diagnosed w/↑ frequency due to availability of better lab assays like multiplex PCR. Therapeutic modalities are few w/mixed results (Infect Dis Clin N Am 2010;24:395).

Infection Control: Transmission-based Precautions

Hand Hygiene: Most effective method of preventing transmission of infxn (Am J Infect Control 2007;35:S65)