Blood Culture Contamination

Infection vs. CNS Contamination

Early identification of Coagulase-Negative Staph (CNS) to help identify patient with contaminated blood cultures and avoid unnecessary antibiotic use, length of stay and costs.


“The clinical impact of the PNA FISH test was the ability of the hospital AMT to get early results. This allowed them to evaluate the patients and to ensure accurate antimicrobial therapy and reduce unnecessary usage of vancomycin by preventing or limiting the treatment of CNS contaminants in blood cultures.”

Forrest et al. J Antimicrob Chemother. 2006 Jul;58(1):154-8.
 

Related Links
 Brochure
 
 
 
 

The Challenge

Up to 30% of All Positive Blood Cultures are Due to Contamination

Staphylococci are the most frequent causes of bloodstream infections and blood culture contamination. True infections with Staphylococcus aureus present considerable clinical challenges and increase mortality rates, prolong hospital stays and add significant extra costs. Blood culture contamination with Coagulase-Negative Staph (CNS), on the other hand, leads to unnecessary coverage with broad-spectrum antibiotic therapy, extra length of stay and unnecessary extra hospital costs.

In most hospitals Gram-Positive Cocci in Clusters (GPCC) represent more than 50% of all positive blood cultures, and more than 60% of these are due to CNS blood culture contamination.

The challenge for physicians is how to ensure early, appropriate therapy for patients with true infections, while avoiding unnecessary therapy for patients with contaminated blood cultures.
 
  
 

The Dilemma

Conventional Identification of CNS vs. S. aureus Takes 1-2 days
Gram Stain - GPCC
  • Cannot distinguish CNS from S. aureus in Gram stain.
    • Does the staphylococci in the positive blood culture represent true infection or contamination?
    • When to discontinue therapy for CNS contamination?
  • Conventional culture and phenotypic identification can take an additional 1-3 days.
  • Patients with CNS contaminated blood cultures are often unnecessarily covered with vancomycin.
 
 

PNA FISH® Solution

Rapid Identification and Differentiation of CNS from S. aureus
S. aureus and CNS
  • 90 min. molecular identification and differentiation of CNS from S. aureus directly from positive blood culture.
  • Aid in early identification of CNS contaminated blood cultures.
  • Proven to help:
    • Reduce unnecessary vancomycin use due to CNS contamination.(8)
    • Shorten length of stay (LOS).(8)
    • Lower hospital bed, pharmacy and laboratory costs.(8)
 
 

Proven Benefits

Shorten Length of Stay (LOS) and Antimicrobial Use for Patients with CNS Contamination

Retrospective study of 87 patients (34 control, 54 PNA FISH®) with Coagulase-Negative Staph positive blood culture performed at the University of Maryland Medical Center (Baltimore, MD).(8)
 

 		  
  • 2 days reduction in length of stay (LOS)
  • Discontinued unnecessary vancomycin use
  • 2.25 defined daily doses (DDD): (4.5 doses) reduction in vancomycin use
 
 
 

Lower Hospital Patient Costs

University of Maryland Medical Center Study.(8)
 
 
  • Total cost-savings of $4,005 per patient
  • $2,704 reduction in hospital bed costs due to reduction in length of stay
  • $985 reduction in pharmacy costs
  • $316 reduction in lab costs (included microbiology, chemistry, haematology, and radiology)
  
 
1.  Ann Clin Microbiol Antimicrob. 2004 May 10:3:7
2.  JAMA. 1991 Jan 16;265(3):365-9
3.  MMWR 44(RR12);1-13 Date: Sep 22, 1995
4.  Poster D-787.  ICAAC 2009. San Francisco, CA
5.  Chest. 2009 Nov;136(5):1237-48.
6.  Infec. Control Hosp Epidemiol. 2009 Nov;30(11):1057-61
7.  Clin Infect Dis. 2009 Aug 1;49(3):325-7
8.  J Antimicrob Chemother. 2006 Jul;58(1):154-8.