Candidiasis

Candidiasis is the most common invasive fungal infection worldwide, and a significant cause of mortality in the ICU patient.

Candidal infections also include the more pedestrian mucous membrane infections of the systemically well, which are caused by local overgrowth of yeast and respond well to topical treatment.

These are not covered here.

Epidemiology and Risk Factors

Risk factors:

  • ICU admission
  • Immunocompromise
    • Transplant
    • Haematological malignancy
    • Diabetes
  • For non-albicans:
    • TPN
    • Central access
    • Antimicrobial exposure:
      • Broad spectrum antibiotics
      • Fluconazole
    • Malignancy
    • Renal failure

Pathophysiology

Candida is:

  • A genus of yeasts
    Over 100 different species, ~20 of which are pathogens.
  • Part of the normal skin and gut flora

Aetiology

Causes have been classically divided on epidemiological and fluconazole-sensitive grounds into:

The ongoing utility of this classification is questionable as the non-albicans infections have become increasingly common, and albicans has become increasingly resistant to fluconazole.

  • C. albicans
    ~50% of all infections; less common if fluconazole prophylaxis has been used.
  • Non-Albicans infections
    All the rest:
    • C. auris
      Multi-drug resistant form, though still generally sensitive to echinocandins.
    • C. glabrata
      ~25% of infections, ↑ azole resistance.
    • C. krusei
      ↑ Azole resistance.
    • C. parapsilosis
    • C. dubliniensis
    • C. tropicalis

Clinical Features

Features are non-specific and include:

  • Fever
    Generally unreliable, though may be high with hepatosplenic abscesses.
  • Sepsis
    Non-responsive to other antimicrobial therapy.

Diagnostic Approach and DDx

Differentiating invasive candidiasis from culture of a normal commensal requires any of:

  • Culture from a sterile site, e.g.
    • Blood
    • Body cavity
  • Culture from wound or burn site
  • Cultured species is non-commensal

Consider initiating treatment if Candida is cultured from ⩾2 non-sterile sites and the patient is septic despite appropriate antibiotic treatment.

Supportive features include:

  • Radiographic fungal lesions
    May be suppressed during neutropaenia.

Investigations

Bedside:

Laboratory:

  • Blood
    • Blood cultures
  • Sputum
    • Bronchoalveolar lavage
  • Other fluid culture

Imaging:

Other:

Management

Specific therapy:

Antifungal therapy is covered in detail under ?sec-antifungal.

  • Pharmacological
    • Antifungal
      • Echinocandin as initial therapy
      • Fluconazole as step-down therapy
        If sensitivity is proven.
    • ↓ Immunosuppressants
  • Procedural
    • Source control
    • Remove lines and devices

Supportive care:

  • G
    • Adequate nutrition

Marginal and Ineffective Therapies

Anaesthetic Considerations

Complications

Candidiasis causes a large number of organ-specific complications:

  • B
    • Pulmonary candidiasis
      Cavitating lung lesions.
  • C
    • Endocarditis
      • Very high mortality
  • D
    • Endophthalmitis
      3-15 days following infection.
  • E
    • Candidal joint infections
    • Skin lesions
    • Muscle abscesses
  • G
    • Hepatic abscess
  • H
    • Splenic abscess

Prognosis

Mortality in the ICU patient is up to 50%. Poor prognostic signs:

  • Late diagnosis

Key Studies

References

  1. Chow JK, Golan Y, Ruthazer R, Karchmer AW, Carmeli Y, Lichtenberg D, et al. Factors Associated with Candidemia Caused by Non-albicans Candida Species Versus Candida albicans in the Intensive Care Unit. Clinical Infectious Diseases. 2008 Apr 15;46(8):1206–13.
  2. Bersten, A. D., & Handy, J. M. (2018). Oh’s Intensive Care Manual. Elsevier Gezondheidszorg.