Background: Candida bloodstream infection (BSI) remains one of the leading causes of BSI in critically ill and immunosuppressed cancer patients. In light of the changing epidemiology and rising resistant species, duration of treatment and appropriate timing of stepdown therapy from intravenous (IV) to oral antifungal agents are crucial for utmost disease control and overall survival.
Method: We performed a multicenter retrospective study, with 119 non-neutropenic patients enrolled from four different medical institutions in Brazil, Lebanon, Spain and the United States, to assess the duration of IV therapy and appropriate time to step-down to oral therapy in adult patients, 14 years of age and older, with documented candidemia. The analysis was done using the statistical program R and SAS v9.4. Descriptive statistics are presented as frequencies and tables and the Fisher exact test was used to test the association between the categorical variables: organism, cancer, country, antifungal drug and duration of therapy, and time of step-down.
Results: Candida albicans contributed to 45% of bloodstream infection versus 55% of infection caused by Candida non-albicans. The three most common Candida non-albicans are: Candida glabrata 24%, Candida parapsilosis 13% and Candida tropicalis 8%. Most (57%) of the patients were admitted to ICU, whereas 52% had underlying malignancy. Multivariate analysis showed that a stay at ICU or an underlying cancer requiring chemotherapy were independently associated with failure and death (p <0.001). The average total duration of therapy was 14 days in all patients and 16 days in those who responded and survived. Forty-five patients were stepped down to either fluconazole and/or voriconazole in association with clinical and microbiologic resolution of the candidemia. The average (and median) day of step-down was 5 days. Patients who had a stepdown had more favorable outcomes (78% survival) as compared to those with no stepdown (56% survival) (P = 0.022). However, the 20 patients who received 1-4 days of first IV treatment before a stepdown to oral azoles had a comparable outcome (20% mortality) to the 25 patients who received >5 days of treatment (24% mortality - p = 0.75).
Conclusion: Our data support the IDSA guidelines in that the total duration of treatment for candidemia should be at least 14 days after a negative blood culture. However, in non-neutropenic cancer patients with candidemia, a step-down to oral azole therapy can safely take place early (within 4 days of initiating IV therapy) as long as the patient had clinical and microbiologic resolution of the bloodstream infections.
Keywords: Bloodstream infection; Candida infections; Neutropenia.