Evaluation of a commercial multiplex PCR (SeptiFast) in the aetiological diagnosis of community-acquired bloodstream infections

Abstract number: P1831

Josefson P., Strålin K., Ohlin A., Ennefors T., Dragsten B., Andersson L., Fredlund H., Mölling P., Olcén P.

Objectives: The SeptiFast test is a commercial PCR test which detects 25 bacterial and fungal pathogens in whole blood samples within 6 hours. We aimed to evaluate the SeptiFast test on consecutive adult patients subjected to blood culturing during one full year at an infectious diseases clinic, predominantly on hospital admission.

Methods: In a prospective study we included for evaluation the first blood culture (BC)/PCR set (two BC bottles and one PCR tube) providing a positive culture and/or PCR result if any positive result was noted. The PCR results were compared with the results of BC and other microbiological data. In addition, positive PCR results without microbiological support were related to the clinical presentation.

Results: Among 1092 included patients BC was positive in 138 patients and PCR was positive in 107 patients. The positive PCR results were supported by BC in the same BC/PCR set in 50 cases, by other cultures in another 10 cases, and by the clinical presentation in additionally 9 cases. No patient with positive BC was PCR positive for another pathogen. Compared with BC, PCR showed specificities and neg predictive values of >97% for all detectable pathogens. The following sensitivities and positive predictive values (PPV) were noted: Staphylococcus aureus, 67% and 43%; Streptococcus species, 43% and 77%; Streptococcus pneumoniae, 12% and 67%; Escherichia coli, 53% and 56%; and Klebsiella species 43% and 23%. If other cultures and clinical presentation were included in the reference standard, the PPV for detection of these bacteria rose to 57%, 92%, 100%, 75% and 62%, respectively.

Conclusion: The SeptiFast test showed high specificities for detection of community-acquired blood stream infections. However, the low sensitivities and suboptimal PPV of the test are essential shortcomings that prohibit a routine use of the test in its present form.

Session Details

Date: 10/04/2010
Time: 00:00-00:00
Session name: Abstracts 20th European Congress of Clinical Microbiology and Infectious Diseases
Location: Vienna, Austria, 10 - 13 April 2010
Presentation type:
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