Clinical characteristics and implications of mixed candida/bacterial bloodstream infections in patients with hematological diseases

The incidence of mixed candida/bacterial blood infections (BSIs) has been reported to account for 20% of all cases of candidaemia. However, its clinical characteristics and implications in patients with hematological diseases are not clear. We conducted a retrospective case-control study of hematological patients complicated with candidaemia over the past 5-year period to identify the risk factors and clinical implications of mixed candidia/bacterial BSIs (case group) vs. monobacterial candidiasis (control group). Of all 65 enrolled patients with candidaemia, 20 cases (30.8%) met the diagnostic criteria for mixed candida/bacterial BSIs. Candida tropicalis was the most common candida species in all patients. Klebsiella pneumoniae was the most detected bacteria (35%) in case group. Previous hospital stay ≥ 28 days, organic damage during candidaemia, and positive procalcitonin (PCT) test were the risk factors of mixed candida/bacterial BSIs. Cumulative mortality of all patients enrolled was 26.2% at day 30, with significant differences between case and control group. In multivariate analysis, organic damage and granulocyte recovery were the two predictive factors for 30-day mortality. Mixed candida/bacterial BSIs are fatal complications of infection which account for a considerable part of candidaemia; multicenter and large-scale clinical studies are required in the future.