Introduction

Bloodstream infection with Candida is a serious invasive fungal infection. It is considered the third most common cause of bloodstream infections in ICUs in the United States [1]. The incidence of health care-associated candidemia has risen by over 50% in the last decade [2]. Factors contributing to this increase include the presence of central venous catheters (CVCs), patient frailty, immunosuppression, overuse of antibiotics, delayed diagnosis, and variability in antifungal susceptibility. Other risk factors, such as hematological malignancies, total parenteral nutrition (TPN), and major abdominal surgery, also predispose patients to candidemia [3]. Candidemia has contributed to poor patient outcomes, longer hospital stays, substantial health care costs, morbidity, and mortality [2]. Mortality rates vary, with estimates ranging from 30% to 60%. Some studies indicate that overall mortality can be as high as 40.4% [4].

Multiple species of Candida have been found to cause human disease, but more than 90% of invasive disease is caused by the five most common pathogens: Candida albicans, Candida glabrata, Candida tropicalis, Candida parapsilosis, and _Candida krusei _[5]. This proportion may vary depending on the geographical region and patient population. Overall, _C. albicans _remains the leading cause of candidemia. Non-albicans _Candida _species account for approximately two-thirds of cases [6]. There has been a major shift in the Candida species causing invasive bloodstream infections. However, C. albicans remains the most common species [7]. Non-albicans _Candida _species, such as C. glabrata, C. parapsilosis, and C. tropicalis, have been found to exhibit reduced susceptibility or intrinsic resistance to antifungal agents, particularly fluconazole, which can lead to persistent infection and increased mortality [8].

Since its first isolation from the ear canal of a 70-year-old Japanese woman in Tokyo in 2009, Candida auris has spread rapidly and has been reported worldwide [9,10]. The risk factors associated with _C. auris infection are similar to those for other Candida species and include ICU stay, CVC, broad-spectrum antibiotic use, and prior antifungal use. However, differences in antifungal susceptibility pose a major challenge in its treatment. Most Candida _species cause infection through autoinfection from the host's endogenous microflora. However, _C. auris _is primarily acquired exogenously and is likely transmitted through contaminated environments, equipment, medical devices, and person-to-person contact via contaminated skin. Its ability to survive on biotic and abiotic surfaces for several weeks or even months makes it one of the most persistent organisms in the hospital environment. Therefore, implementation of strict infection prevention and control practices is essential to prevent transmission and subsequent invasive infections within health care settings, as _C. auris _is associated with cross-transmission, drug resistance, prolonged hospitalization, increased health care costs, morbidity, and high mortality [11].

Because of its high rate of antifungal resistance, _C. auris _is more difficult to treat, requires longer hospital stays, and is associated with higher morbidity and mortality than other _Candida _species. Approximately 90% of _C. auris _isolates in the United States are reported to be resistant to fluconazole, and 30% are resistant to amphotericin B, with resistance rates continuing to increase [12]. Resistance in C. auris is expanding, and echinocandin-resistant C. auris has also been reported [13]. Because echinocandins are the first-line therapy for invasive Candida infections caused by C. auris, resistance may make these bloodstream infections difficult to treat [14]. In a systematic review by Kim et al., the reported 30-day mortality rates associated with _C. auris _candidemia ranged from 29% to 62% across different studies [11].

There has been a significant increase in C. auris cases in Oman since it was first reported in 2016, with outbreaks occurring in health care institutions throughout the country between 2018 and 2019 [15,16]. Despite its rising incidence and significant health care impact in the country, there is a lack of studies comprehensively comparing _C. auris _infections with non-_C. auris _infections. Therefore, this study aimed to compare the clinical associations, in-hospital mortality, and antifungal susceptibility patterns between the two groups.