SeptiFast PCR combined with blood cultures for the microbiological documentation of fever in neutropenic cancer patients

Abstract number: P1133

Jaton-Ogay K., Lamoth F., Prodhom G., Senn L., Marchetti O., Calandra T., Bille J.

Background: Blood cultures (BC) identify the aetiology in only 1/3 of febrile neutropenic episodes. New diagnostic tools are thus needed for guiding investigations and antimicrobial therapy. LightCycler SeptiFast (Roche) is a real-time PCR for the detection of bacterial (9 G+ and 10 G- species) and fungal DNA (6 species) in blood.

Objective: To assess the utility of SF combined with BC for the microbiological documentation of fever in neutropenic cancer patients.

Material and Methods: Blood samples for BC (4 aerobic + anaerobic sets, Bactec 9140) and SF (4 EDTA tubes) were drawn simultaneously in adult febrile neutropenic cancer patients undergoing myeloablative chemotherapy for haematological malignancies. Microbiological documentation by SF and BC were analysed.

Results: 186 samplings (SF/BC 1:1) were analysed in 119 febrile episodes. 18/186 (9.6%) SF analyses were invalid (contamination of negative control), 12 (6.4%) were inhibited. 88 pathogens were detected in 59/119 (50%) febrile episodes by BC and/or SF (see table).

Using BC as reference, sensitivity of SF was 50%, specificity 64%, PPV 29%, NPV 81% and efficiency 60%. BC were positive in 20/74 (27%) and SF in 14/74 (19%) samplings drawn in the absence of antibiotic therapy. For samplings drawn during antibacterial therapy, BC were positive in only 12/112 (11%), whereas SF detected pathogens in 38/112 (34%, p < 0.001).

Conclusions: Septifast combined with blood cultures is a promising tool for the microbiological documentation in febrile neutropenic cancer patients.

Session Details

Date: 19/04/2008
Time: 00:00-00:00
Session name: 18th European Congress of Clinical Microbiology and Infectious Diseases
Location: Barcelona, Spain
Presentation type:
Back to top