Molecular diagnosis of bloodstream infections in onco-haematology patients with PCR/ESI-MS technology

•This is the first evaluation of IRIDICA for the molecular diagnosis of sepsis in both oncology and haematology patients.•IRIDICA detected 44 relevant microorganisms not isolated by culture and missed 31.•IRIDICA showed better sensitivity in oncological than in haematological patients (81.3 vs. 71.4%, by specimen).•The use of IRIDICA could lead to an earlier administration of targeted antibiotic therapy, especially in oncology patients.

SummaryObjectivesOnco-haematological patients are prone to develop infections, and antibiotic prophylaxis may lead to negative blood cultures. Thus, the microbiological diagnosis and subsequent administration of a targeted antimicrobial therapy is often difficult. The goal of this study was to evaluate the usefulness of IRIDICA (PCR/ESI-MS technology) for the molecular diagnosis of bloodstream infections in this patient group.MethodsA total of 463 whole blood specimens from different sepsis episodes in 429 patients were analysed using the PCR/ESI-MS platform, comparing the results with those of blood culture and other clinically relevant information.ResultsThe sensitivity of PCR/ESI-MS by specimen (excluding polymicrobial infections, n = 25) in comparison with blood culture was 64.3% overall, 69.0% in oncological patients, and 59.3% in haematological patients. When comparing with a clinical infection criterion, overall sensitivity rose to 74.7%, being higher in oncological patients (80.0%) than in haematological patients (67.7%). Thirty-one microorganisms isolated by culture were not detected by IRIDICA, whereas 42 clinically relevant pathogens not isolated by culture were detected moleculary.ConclusionsPCR/ESI-MS offers a reliable identification of pathogens directly from whole blood. While additional studies are needed to confirm our findings, the system showed a lower sensitivity in onco-haematological patients in comparison with previously reported results in patients from the Intensive Care Unit.