Infectious Disease · Topic 8 of 10
Invasive Fungal Infections
Infectious disease · fungal infections
Invasive Fungal Infections
Candidemia: echinocandin, pull the line, dilated eye exam, 14 days after clearance. Invasive aspergillosis in the neutropenic or transplant patient: voriconazole.
Key numbers
Treat 14 days after blood clears14 d after clearance
Step down to fluconazole in 5–7 daysstep-down 5–7 d
Treat aspergillosis at least 6–12 weeks≥ 6–12 weeks
01 · GiveEchinocandin first for candidemia
Start an echinocandin for candidemia: caspofungin 70 mg load then 50 mg daily, micafungin 100 mg daily, or anidulafungin 200 mg load then 100 mg daily (IDSA 2016, strong recommendation).
02 · DoRemove the central venous catheter early
In nonneutropenic patients with candidemia, remove central venous catheters as early as possible — the line is a typical portal of entry and source.
03 · The ruleTreat 14 days after blood clears
Treat candidemia without metastatic complications for 2 weeks after documented clearance of Candida from the bloodstream and resolution of symptoms; draw follow-up blood cultures daily or every other day until negative.
01
Causes & risk factors
Why it happensCentral lines, TPN, broad antibiotics raise candidemia riskCandidemia risk rises with central venous catheters, broad-spectrum antibiotics, parenteral nutrition, neutropenia, immunosuppression and prolonged hospitalization; the catheter and the GI tract are the usual portals of entry.
C. glabrata, C. krusei, C. auris resist fluconazoleC. glabrata (Nakaseomyces glabrata) is less fluconazole-susceptible, C. krusei (Pichia kudriavzevii) is intrinsically fluconazole-resistant, and multidrug-resistant C. auris spreads in hospitals — all are treated first with an echinocandin.
Prolonged neutropenia and transplant: think AspergillusInvasive aspergillosis follows inhaled spores in the severely immunocompromised: neutropenia lasting more than 7 days, stem cell transplant with graft-versus-host disease, solid organ transplant, prolonged glucocorticoids and chronic granulomatous disease.
02
Diagnosis & monitoring
Work-upDilated eye exam within the first week must knowEvery nonneutropenic patient with candidemia needs a dilated ophthalmologic examination, ideally within the first week, to detect Candida endophthalmitis, which starts as asymptomatic white retinal lesions.
Galactomannan in serum or BAL fluidSerum and BAL galactomannan are accurate markers of invasive aspergillosis in hematologic malignancy and stem cell transplant; don't use serum galactomannan for routine screening during mold-active prophylaxis, though BAL fluid can still be tested.
Check voriconazole levels at steady statePerform therapeutic drug monitoring of mold-active triazoles such as voriconazole once steady state is reached.
03
Do right now
In this orderFirst moves
1
→Echinocandin first for candidemia
2
→Remove the central venous catheter early
3
→Dilated eye exam within the first week
4
Treat 14 days after blood clears14 d after clearance
Why each step
Echinocandin first for candidemiaStart an echinocandin for candidemia: caspofungin 70 mg load then 50 mg daily, micafungin 100 mg daily, or anidulafungin 200 mg load then 100 mg daily (IDSA 2016, strong recommendation).
Remove the central venous catheter earlyIn nonneutropenic patients with candidemia, remove central venous catheters as early as possible — the line is a typical portal of entry and source.
Dilated eye exam within the first weekEvery nonneutropenic patient with candidemia needs a dilated ophthalmologic examination, ideally within the first week, to detect Candida endophthalmitis, which starts as asymptomatic white retinal lesions.
Treat 14 days after blood clearsTreat candidemia without metastatic complications for 2 weeks after documented clearance of Candida from the bloodstream and resolution of symptoms; draw follow-up blood cultures daily or every other day until negative.
04
Management
OrdersVoriconazole for invasive aspergillosis must knowVoriconazole is the primary treatment for invasive aspergillosis; isavuconazole (isavuconazonium) or posaconazole are equally effective with fewer adverse effects, and liposomal amphotericin B is the alternative.
Step down to fluconazole in 5–7 daysSwitch from the echinocandin to fluconazole, usually within 5–7 days, once the patient is clinically stable, the isolate is fluconazole-susceptible and repeat blood cultures are negative.
Empiric echinocandin for the high-risk septic ICU patientConsider empiric antifungal therapy in critically ill patients with risk factors for invasive candidiasis and no other cause of fever; an echinocandin is the preferred empiric agent in nonneutropenic ICU patients.
Chest CT whenever aspergillosis is suspectedOrder a chest CT whenever invasive pulmonary aspergillosis is suspected — far more sensitive than radiography; look for nodules with a halo sign (surrounding ground-glass haze) or cavitation.
05
The rules
Know theseCandida in blood is never a contaminantCandida from blood or another sterile site is definitive evidence of invasive infection and always needs systemic therapy; Candida in sputum or respiratory secretions usually means colonization and rarely needs treatment.
Asymptomatic candiduria: remove the catheter, don't treatDo not treat asymptomatic candiduria — remove the bladder catheter — unless the patient is neutropenic, a very-low-birth-weight infant or about to undergo urologic manipulation.
Treat aspergillosis at least 6–12 weeksContinue treatment of invasive pulmonary aspergillosis for at least 6–12 weeks and reduce or stop immunosuppressive drugs when feasible; recurrence is common if neutropenia returns.
06
Candidemia or invasive aspergillosis?
Commonly confused| Typical host | ICU patient with a central line, TPN, broad antibiotics |
|---|---|
| Diagnosis | Blood culture |
| First-line drug | Echinocandin, step down to fluconazole |
| Source control | Remove the central line |
| Duration | 14 days after blood clears |
07
More detail
ReferenceShow 6 reference facts
Serum (1,3)-β-D-glucan is often positive in invasive candidiasis and a negative result makes it unlikely; Candida PCR is more sensitive and, combined with blood cultures, is about 98% sensitive.
Lipid amphotericin B (3–5 mg/kg daily) is the alternative for intolerance, limited availability or resistance to other antifungals; for C. krusei an echinocandin, lipid amphotericin B or voriconazole is recommended.
Combining voriconazole with an echinocandin may be considered in selected patients with documented invasive aspergillosis; echinocandins alone are salvage therapy for aspergillosis.
Posaconazole prophylaxis is generally recommended for patients at high risk of aspergillosis, such as those with graft-versus-host disease or protracted neutropenia from acute myeloid leukemia.
An aspergilloma (fungus ball in an old lung cavity) does not respond to systemic antifungals; resection is considered for local complications, especially hemoptysis.
For C. glabrata, step down to high-dose fluconazole 800 mg daily or voriconazole only if the isolate is susceptible.
Candida in the blood is never a contaminant: echinocandin, line out, eyes checked, 2 weeks from the first clean culture.
Sources · Pappas PG et al. Clinical Practice Guideline for the Management of Candidiasis: 2016 Update by the IDSA. Clin Infect Dis 2016;62(4):e1–e50 · Merck Manual Professional — Candidiasis (Invasive) · Patterson TF et al. Practice Guidelines for the Diagnosis and Management of Aspergillosis: 2016 Update by the IDSA. Clin Infect Dis 2016;63(4):e1–e60 · Merck Manual Professional — Aspergillosis (Nov 2025) · Starter sheet built from the verified AGACNP fact map (facts reviewed 2026-10-15).