Fungemia

Background

• Bloodstream infection with a species of fungi; for the purposes of this page, focussing on yeast alone, and Candida in particular

Microbiology

• Candida albicans (46%)
• Candida glabrata (26%)
• Candida parapsilosis (16%)
• Candida tropicalis (8%)
• Candida krusei (3%)
• Candida auris (rare): growing concern for multidrug resistance
• Numbers based on https://doi.org/10.1086/599039

Risk Factors

• Hospital-onset
  • Multiple or long-term IV lines, central lines, etc.
  • Long-term and broad-spectrum antibiotic use, especially in ICU
  • Immunocompromise, including solid-organ and hematologic transplantation, hematologic malignancy, chemotherapy, and other immunosuppression
  • Total parenteral nutrition
  • Acute kidney injury, especially requiring dialysis
  • Abdominal surgery
  • Gastrointestinal perforation
• Community-onset1
  • Hospitalization within the past month
  • HIV, malignancy, neutropenia, and diabetes similar to hospital-onset
  • Less immunosuppressive therapy, recent surgery, or central venous catheters than hospital-onset, but still risk factors

Clinical Manifestations

• Positive blood culture for a Candida
• Fever
• Triad of bowel perforation, increase white cell count, and decreased platelets
• Ocular infections in 16% (2-20%), which as primarily chorioretinitis, although endophthalmitis is possible2
  • Less common with prompt diagnosis and treatment
  • Chorioretinitis shows focal, yellowish-white infiltrative lesions in the choroid and retina, without vitreal involvement, and most patients do not have visual symptoms
  • Endophthalmitis has vitreal involvement, with fluff balls surrounded by cloudy vitreous, and can result in retinal necrosis and detachment, and is associated with long-term vision loss
• Fungal endocarditis found in 8%
• In patients with community-onset candidemia and candiduria, many have fungal endocarditis

Prognosis

• Mortality of about 25%1

Investigations

• Blood cultures
• Blood count (increased WBCs, decreased platelets)
• Consider echo to rule out endocarditis

Management

• Never treat as a contaminant!
• Recommended ophthalmology consult to rule out endophthalmitis, ideally around 1 week after positive cultures
• Repeat 1 to 2 blood cultures every 24 to 48 hours until negative (1 culture q24h in ESCMID guidelines)
• Antifungal therapy
  • First-line (stable patients): fluconazole if no risk factors for a resistant species
  • Alternative (resistance or septic): micafungin or another echinocandin
  • Alternative (last-line): amphotericin B
• Duration
  • No organ involvement: 14 days from first negative
  • Ocular infection: until resolution of ocular findings, often 4 to 6 weeks
  • Endocarditis: at least 6 weeks; see fungal endocarditis

Ocular Candidiasis

• General preference for azoles (fluconazole and voriconazole), given high intraocular concentrations
• Echinocandins may be adequate for chorioretinitis, but almost certainly inadequate for endophthalmitis
• May need intravitreal injections (voriconazole or amphotericin B) or vitrectomy
• Duration 4 to 6 weeks, but ideally until resolution of lesions on serial fundoscopy (if available)