Invasive Candidiasis Epidemiology and Treatment

Major Pathogens and Epidemiology

Five Candida species account for 92% of invasive candidiasis cases: Candida albicans, Candida glabrata, Candida tropicalis, Candida parapsilosis, and Candida krusei 1, 2, 3
Candida albicans remains the predominant cause of invasive candidiasis in most settings, though there is an increasing shift toward non-albicans species 4, 5
The emergence of non-albicans Candida species is particularly important in specific patient populations, such as C. tropicalis in neutropenic patients and C. glabrata and C. parapsilosis in critically ill non-neutropenic patients 5

C. auris is the most concerning emerging pathogen, classified by the CDC as an urgent public threat due to its association with increased mortality, potential for developing pan-drug resistance, and ability to become entrenched in hospital environments 1, 2, 3, 6
There has been a significant increase in C. auris cases in the USA in recent years, with outbreaks reported across various European countries 6
A tripling of echinocandin-resistant isolates has been observed, further complicating treatment options 6

C. krusei is intrinsically resistant to fluconazole but is relatively rare in most hospital settings 5
Non-susceptibility to fluconazole is becoming a major concern, particularly in C. glabrata and C. tropicalis, with cross-resistance to other triazoles 4, 5

Candida peritonitis is the predominant form of invasive candidiasis after candidemia in ICU patients 1
Intra-abdominal candidiasis has mortality rates exceeding 50%, even with modern antifungal treatments 6
Mixed infections with bacteria are common in intra-abdominal candidiasis, complicating diagnosis and treatment 1, 2
Only 6.9% of patients with intra-abdominal candidiasis have concomitant positive blood cultures for Candida species, making diagnosis challenging 2

Intensive care unit patients are at highest risk for invasive candidiasis 1
Rapid colonization of mucocutaneous surfaces after ICU admission is an important risk factor for candidemia 1
Alterations in the gastrointestinal microbiome typically precede intra-abdominal candidiasis 1
Risk factors include use of antibiotics, central venous catheters, surgical procedures, parenteral nutrition, sepsis, neutropenia, renal failure, mechanical ventilation, immunosuppressive agents, and Candida colonization 5
Standard precautions including hand hygiene are essential as most Candida blood isolates are similar or identical to prior colonization in the patient's urinary and gastrointestinal tracts 5

Differentiation between contamination, colonization, and infection is difficult when Candida is present in intra-abdominal samples 2
Up to 80% of patients with peritonitis are colonized with Candida species, further complicating diagnosis 2