Management of Candida auris Bacteremia
Initiate an echinocandin immediately as first-line therapy for Candida auris bacteremia, as this emerging multidrug-resistant pathogen demonstrates high rates of fluconazole resistance (93%) and requires aggressive treatment with echinocandins as the empiric drugs of choice. 1, 2
Initial Antifungal Therapy
Start an echinocandin as first-line treatment with the following dosing options 3, 1:
- Caspofungin: 70 mg loading dose, then 50 mg daily
- Micafungin: 100 mg daily
- Anidulafungin: 200 mg loading dose, then 100 mg daily
Do not use fluconazole empirically, as 93% of C. auris isolates demonstrate fluconazole resistance (MIC >256 mg/liter) 2
Lipid formulation amphotericin B (3-5 mg/kg daily) serves as an alternative option, though 35% of isolates show amphotericin B resistance 3, 2
Critical Diagnostic and Monitoring Steps
Obtain antifungal susceptibility testing immediately on all C. auris isolates, testing for both azole and echinocandin susceptibility, as 7% of isolates are echinocandin-resistant and 41% are resistant to two antifungal classes 3, 2
Perform follow-up blood cultures daily or every other day to document clearance of the organism 3, 4
Conduct a dilated ophthalmological examination within the first week after diagnosis to rule out endophthalmitis 3, 4
Consider transoesophageal echocardiography to evaluate for endocarditis 4
Source Control Measures
Remove central venous catheters as early as possible when the catheter is the presumed source and can be safely removed, as 73% of C. auris patients have central venous catheters 3, 2
Implement aggressive infection control measures immediately, as C. auris is capable of causing nosocomial outbreaks and requires stringent transmission prevention 1
Treatment Duration
Continue antifungal therapy for a minimum of 14 days after documented clearance of Candida from the bloodstream and resolution of symptoms attributable to candidemia 3, 4
Do not discontinue therapy prematurely before documented clearance, as this can lead to relapse 5
Special Considerations for Multidrug-Resistant Isolates
For isolates resistant to both azoles and echinocandins (4% resistant to 3 antifungal classes), consider combination therapy with flucytosine 2
Echinocandin-flucytosine combinations (such as micafungin 0.12 mg/liter + flucytosine 1.0 mg/liter) achieved 100% inhibition in vitro against triple-class resistant C. auris isolates 6
For amphotericin B-resistant isolates (MIC ≥2.0 mg/liter), amphotericin B-flucytosine combination (0.25/1.0 mg/liter) yielded 100% inhibition in vitro 6
Common Pitfalls to Avoid
Never use fluconazole as initial therapy without confirmed susceptibility testing, given the 93% resistance rate 2
Do not assume echinocandin susceptibility, as resistance can develop on therapy and 7% of isolates are already echinocandin-resistant 1, 2
Recognize that C. auris can be difficult to identify using traditional biochemical methods, potentially leading to delayed appropriate therapy 1
Be aware that 59% mortality has been reported in C. auris infections, emphasizing the need for prompt, aggressive treatment 2
Clinical Context
C. auris predominantly affects hospitalized patients with significant comorbidities: 41% have diabetes mellitus, 51% have undergone recent surgery, and 41% were receiving systemic antifungal therapy when C. auris was isolated 2
The median time from admission to infection is 19 days, indicating this is primarily a healthcare-associated pathogen 2
Whole-genome sequencing demonstrates that C. auris emerged nearly simultaneously on three continents as distinct clonal populations, with different ERG11 mutations associated with azole resistance in each geographic clade 2