Mixed fungemia: an 18-year report from a tertiary care university hospital and a systematic review

Abstract Background While fungemia caused by ≥2 different species of yeasts (mixed fungemia, MF) is infrequent, it might be underestimated. Objectives This study aimed to determine the incidence of MF, clinical characteristics of the patients, and antifungal susceptibility profiles of the isolates with a systematic review of the literature. Data sources PubMed, Scopus. Study eligibility criteria Studies reporting ≥10 mixed fungemia episodes. Methods Study included MF episodes in adults between January-2000 and August-2018 in Hacettepe University Hospitals. The isolation, identification and antifungal susceptibility testing (AFST) of the isolates were by standard mycological methods. Patient data were obtained retrospectively. Literature search was performed using relevant keywords according to PRISMA systematic review guidelines. Results A total of 32 patients with 33 MF episodes were identified. Among all fungemia episodes, MF incidence was 3.7% (33/883). All patients had ≥1 underlying disorders among which solid organ cancer (50.0%, 16/32) was the most common. Overall mortality was 51.5% (17/33). The most preferred antifungal agents for initial treatment were fluconazole (48.5%, 16/33), and echinocandins (39.4%, 13/33). Fluconazole susceptible-dose-dependent (S-DD) or resistant Candida species were detected in 15 episodes and a C. parapsilosis isolate was classified as S-DD by AFST. All Candida isolates were susceptible to echinocandins. Non-Candida yeasts with intrinsic resistance/reduced susceptibility to both echinocandins and fluconazole were detected in two episodes. Systematic review of the literature revealed 24 studies that reported u003e10 MF episodes. Methodology was variable. Improvement of detection rates was reported when chromogenic agars were used. Most studies underlined detection of isolates with reduced susceptibility. Conclusions Although rare, MF rate is affected by the detection methods, which improved in recent years. Fluconazole and echinocandins were used for initial treatment in accordance with the current guideline recommendations, however isolates non-susceptible to both were detected. Detection of a mixed infection offers an opportunity for optimum treatment.