The goal of this observational study is to assess if the molecular diagnostic tool BioFire FilmArray BCID2 is more useful for the microbiological diagnosis of bloodstream infections in hematological patients with febrile neutropenia, compared to the conventional microbiologic studies.

The study compares the sensibility and specificity of these two techniques.

Inclusion Criteria:

• Age ≥18 years
• Patients hospitalised for the treatment of haematological malignancy or undergoing an autologous or allogeneic hematopoietic stem cell transplant or receiving CAR-T cell therapy
• Patients presenting with febrile neutropenia (defined as axillary temperature ≥ 38.0°C and <500 neutrophils/mm3 or <1000 with an expected rapid decrease in 24-48 hours),
• Patient to whom blood cultures are ordered as standard care for the microbiological diagnosis of the febrile neutropenia episode.

Exclusion Criteria:

• Axillary temperature <37.5ºC.
• High clinical suspicion of a non-infectious cause of fever at the moment when blood cultures are drawn (high suspicion of drug related fever, infusion reaction).
• Previously enrolled patients in whom the time between inclusion and the current episode is less than four weeks.
• Patients with febrile neutropenia in whom no blood cultures are drawn.

This study will include adult patients (age ≥18 years) hospitalised for the treatment of leukaemia, lymphoproliferative syndrome, myelodysplastic syndrome, multiple myeloma, medullary aplasia, or patients undergoing an autologous or allogeneic hematopoietic stem cell transplant or receiving CAR-T cell therapy, who develop febrile neutropenia (defined as axillary temperature ≥ 38.0°C and <500 neutrophils/mm3 or <1000 with an expected rapid decrease in 24-48 hours), and who have diagnostic blood cultures ordered as standard care for the microbiological diagnosis of the febrile neutropenia episode.

Patient´s age and sex, underlying disease and immunosuppressive therapies, clinical presentation, vital signs, duration of neutropenia, date of the initial blood cultures collection, cultures from other sites of infection collected within a time window of 10 days, blood count and chemistry, (including inflammatory biomarkers), and antimicrobial prescription (previous, current and posterior to the febrile neutropenia onset during study observation and 30 days before). Data regarding the microbiological results of the collected samples for each episode of febrile neutropenia will be collected. Date and time of febrile neutropenia episode, of blood cultures drawing and of blood cultures reception at Microbiology Laboratory will be registered. For both strategies microorganism identification, time to species identification, resistance mechanisms and time to resistance mechanism detection will be registered.

The study protocol is being written, and is planned to be published during the first six months of 2025

The study protocol will be published in an Open access journal.