Fungemia-Introduction, Common Fungi, Clinical Feature, Lab Diagnosis, Treatment, and Prevention

Introduction

Fungemia refers to the presence of fungi in the bloodstream, indicating systemic fungal infection. Candida species are most commonly responsible, but other yeasts and molds may also invade the bloodstream.

Fungemia is a medical emergency, especially in ICU patients, immunocompromised hosts, post-surgical cases, and neonates. Mortality rates can exceed 40% if diagnosis and treatment are delayed.

Common Fungi Causing Fungemia

Fungus	Features
Candida albicans	Most common; forms pseudohyphae
Candida glabrata	Less susceptible to azoles
Candida tropicalis	Common in neutropenic cancer patients
Candida parapsilosis	Catheter-associated infections
Candida auris	Emerging multidrug-resistant yeast
Cryptococcus neoformans	Seen in AIDS and transplant patients
Aspergillus spp.	Rare in blood cultures; usually seen in tissue
Fusarium spp.	May show true fungemia, especially in leukemia
Histoplasma capsulatum	Disseminates in AIDS, endemic areas

Clinical Features

• Fever not responding to antibiotics
• Chills, hypotension, tachycardia
• Signs of sepsis or septic shock
• Organ-specific signs: liver, kidney, CNS, retina, heart
• Skin lesions (e.g., Candida tropicalis fungemia)
• Dissemination in immunocompromised hosts

Laboratory Diagnosis

Test	Role
Blood culture (BACTEC, BacT/Alert)	Gold standard, but sensitivity is limited (~50%)
Fungal culture on SDA	Species identification from blood or catheter
Beta-D-glucan assay	Pan-fungal marker; elevated in many fungal infections
T2 Candida panel	Rapid, species-level detection directly from blood
MALDI-TOF MS	Rapid ID from positive culture
PCR-based panels	Detects fungal DNA; useful in early diagnosis
Antifungal susceptibility testing (AFST)	Guides targeted therapy

Treatment

Situation	Treatment
Stable, non-neutropenic	Fluconazole, if susceptible
Severely ill or neutropenic	Echinocandins (e.g., caspofungin, micafungin)
C. auris / resistant strains	Liposomal Amphotericin B, Echinocandins
Cryptococcal fungemia	Amphotericin B + Flucytosine, then Fluconazole
Aspergillus or Fusarium	Voriconazole or Amphotericin B

Duration: Continue antifungals for 14 days after the last positive blood culture and resolution of signs/symptoms.

Prevention

• Strict catheter care and early removal of unnecessary lines
• Judicious use of broad-spectrum antibiotics
• Limit parenteral nutrition duration when possible
• Use antifungal prophylaxis in high-risk ICU or neutropenic patients
• Maintain good hand hygiene and hospital disinfection
• Screen and isolate C. auris carriers to prevent outbreaks

Keynotes

• Fungemia is a life-threatening condition, especially in critically ill patients.
• Candida spp. are the leading cause; C. auris is an emerging global threat.
• Early diagnosis, removal of the source, and prompt antifungal therapy are essential.
• Culture and non-culture-based methods (T2, BDG) improve detection.
• Prevention includes infection control, antifungal stewardship, and risk stratification.

Further Readings

• https://www.sciencedirect.com/topics/medicine-and-dentistry/fungemia
• https://www.ncbi.nlm.nih.gov/sites/entrez?Db=mesh&Cmd=DetailsSearch&Term=%22Fungemia%22%5BMeSH+Terms%5D
• https://www.amjmed.com/article/0002-9343(79)90073-1/fulltext
• https://www.mdpi.com/2309-608X/9/4/400
• https://www.frontiersin.org/journals/epidemiology/articles/10.3389/fepid.2023.1180331/full
• https://www.scielo.br/j/ramb/a/8WWxwXftPCJ7XZLp7N48MhB/
• https://jamanetwork.com/journals/jamasurgery/fullarticle/588862
• https://www.amjmed.com/article/0002-9343(79)90073-1/fulltext
• https://pubmed.ncbi.nlm.nih.gov/3125578/
• https://www.scielo.br/j/ramb/a/8WWxwXftPCJ7XZLp7N48MhB/
• https://www.numberanalytics.com/blog/managing-fungemia-in-clinical-practice
• https://www.medicoverhospitals.in/diseases/fungemia/