Polymicrobial bloodstream infections (PBI): An under-realized complication in patients with cancer (2005–2006)

Abstract

19590 Background: Little attention has been directed to PBI in cancer patients. Methods: Fifty-four PBI episodes were evaluated retrospectively in 51 patients after obtaining IRB approval. PBI was defined as ≥ 2 organisms isolated from a single blood culture or sample(s) obtained within 72 hrs after the initial positive culture. All values are given as median ± s.d. Results: The age was 57 ± 16 years. Thirty-four patients had hematologic malignancy of whom, 73% had acute leukemia. Nearly half (47%) of the patients had refractory or relapsed cancer. Thirty-two (63%) were neutropenic (ANC 0 ± 144 cells/UL) and 31 patients (61%) had lymphocytopenia (ALC 0 ± 86 cells/UL). At the time of infection diagnosis, APACHE II score was 16 ± 5 and 5 (10%) patients were receiving systemic corticosteroids (> 600 mg prednisone equivalent dose). Thirty-one PBI episodes (57%) occurred while patients were receiving systemic antimicrobial agents for prophylaxis or treatment. In 83% of PBI episodes, positive specimens were collected from central venous catheter (CVC). Catheter-related infection necessitating CVC removal occurred in nearly half of these cases (24/45). Twenty-two (41%) PBI episodes were associated with high bacterial load (> 100 CFU/ml). The overall response to treatment was 86%. In 39 of 42 episodes (77%) treated with concordant antimicrobial therapy infection resolved. Whereas, in only 5 episodes (9%) treated with discordant antimicrobial therapy, infection resolution occurred (P = 0.07). There were no differences in PBI outcomes in patients with hematologic malignancies vs. solid-organ cancers, patients > 50 years vs. < 50 years of age or among neutropenic patients who had recovery of neutropenia during infection episode vs. patients in whom neutropenia persisted. Conclusions: The overall high response of concordant antimicrobial therapy for even high-risk cancer patients with PBI looks encouraging. No significant financial relationships to disclose. [Table: see text]