11 - Fungal Infections Flashcards

1
Q

What are some types of infections associated w/ candida?

A
  • Mucosal candidiasis (oropharyngeal, esophageal, vulvovaginitis)
  • Candidemia
  • Invasive/acute disseminated candidiasis involving visceral site or organ
  • Hepatosplenic/chronic disseminated candidiasis (most often in hematologic malignancy, recent neutropenia)
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2
Q

What are the most common candida species associated w/ infections?

A
  • Albicans
  • Glabrata
  • Parasilosis
  • Tropicalis
  • Krusei
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3
Q

Which candida species are most resistant to anti-fungals?

A

Krusei > glabrata > albicans

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4
Q

What can fluconazole prophylaxis cause?

A

Increased occurrence of non-albicans candidiasis

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5
Q

What is candida auris?

A

Emerging healthcare-associated pathogen w/ multi-drug resistance

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6
Q

What are some risk factors for candidiasis?

A
  • ICU > 4 days, septic shock, broad-spectrum antibiotics
  • Central venous catheter (CVC)
  • Liver transplant, severe pancreatitis
  • Peritoneal-dialysis peritonitis
  • Recent GI surgery!
  • Immunocompromised (hematologic malignancy, chemotherapy, transplant suppression, corticosteroids)
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7
Q

How do corticosteroids suppress the immune system?

A

Affect the function of cells (neutrophils don’t function as normal so immune system doesn’t function as normal)

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8
Q

Why are diabetics immunocompromised?

A

High levels of glucose make neutrophils not function properly

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9
Q

How will candida species appear on a microscope?

A

Budding yeast w/ hyphae or pseudo-hyphae

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10
Q

What test can you do for C. albicans?

A

Germ tube test (positive test = C. albicans)

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11
Q

What is used to diagnose candidiasis?

A
  • Microscopic visualization
  • Culture (60-80% positive in candidemia, 50% in invasive infection)
  • Histopathology for deep-seated infections & mold infections
  • Triazole susceptibility testing
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12
Q

What are the clinical signs and sx of candidiasis?

A
  • Endophthalmitis of choroid and retina, fluffy yellow-white lesions +/- viritis (intraocular inflammation) or retinal hemorrhages
  • Skin lesions w/ pustules on erythematous base
  • Hepatosplenic micro-abscesses (presents w/ persistent fever, RQ pain, increased alkaline phosphatase)
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13
Q

What is C. parapsilosis associated with?

A

Line infection/ catheter (tx is to remove catheter)

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14
Q

What is the prognosis of candidemia?

A
  • 30-40% mortality (lower for C. parapsilosis)

- 3x increase in mortality when antifungal therapy delayed > 12-24 h

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15
Q

What else should be done alongside antifungal therapy for candidemia in non-neutropenic px?

A

Remove and/or replace CVC if the source

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16
Q

What are the antifungal options for candidemia in non-neutropenic px?

A
  • Echinocandin (preferably micafungin)
  • For non-critically ill, non-invasive w/o risk factors for fluconazole resistance – flucon (800 mg PO/IV load, 400 mg q24h
  • [Ampho B]
  • Consider PO step-down from IV to flucon (400 mg q24h) after 5-7 days if sx resolved, clinically stable, flucon-susceptible isolate and negative blood culture
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17
Q

Duration of therapy for candidemia in non-neutropenic px? What should be monitored?

A
  • 2 weeks after negative blood culture

- Monitor temp, BP, blood cultures, and white count

18
Q

What are the most common echinocandin-associated adverse effects?

A
  • Infusion site infections
  • Headache, fever/chills
  • Hypokalemia, decreased hemoglobin, increased LFTs
19
Q

What are the most common amphotericin B-associated adverse effects?

A
  • Infusion-related reaction (TNF, IL) w/ N/V, fever, chills, bronchospasm, hypotension
  • Nephrotoxicity
  • Decreased K and Mg
  • Normocytic anemia
20
Q

What does neutropenia mean?

A

Low WBC counts w/ low % neutrophils (less than 10%)

21
Q

What else should be done alongside antifungal therapy for candidemia in neutropenic px?

A
  • More likely GI source than CVC
  • Consider granulocyte colony-stimulating factors/ granulocyte infusions if persistent infection and prolonged neutropenia
22
Q

What are the antifungal options for candidemia in neutropenic px?

A
  • Echinocandin
  • [Amphotericin B] - for intolerance, resistance, pregnancy
  • Cautiously, for non-critically ill, non-invasive and w/o risk of flucon-R = flucon (800 mg PO/IV load, 400 mg q24h)
  • For additional fungal or mold coverage = voriconazole (400 mg PO/IV q12h x 2 doses then 200-300 mg q12h)
23
Q

Duration of therapy for candidemia in neutropenic px?

A

2 weeks after negative blood culture, resolution of sx and neutropenia

24
Q

Susceptibilities and anti-fungal therapy for candida glabrata?

A
  • Dose-dependent anti-fungal activity; increasing flucon-R and emerging echino-R
  • Echino
  • [HD-ampho B or HD-flucon or voricon]
25
Q

Susceptibilities and anti-fungal therapy for candida krusei?

A
  • Intrinsic flucon-R and relatively high ampho B MICs
  • Echino
  • [Voricon or HD-ampho B]
26
Q

When should empirical anti-fungal therapy be used for candidiasis?

A
  • Based on preliminary microbiology, histopathology, or high-risk
  • High risk = fever despite broad-spectrum antibiotics, critically ill, neutropenic fever, immunocompromised, TPN, GI surgery
27
Q

Which anti-fungals are used for empirical therapy of candidiasis?

A
  • Echino or flucon

- [Ampho B] – covers molds, neutropenic fever w/ flucon prophylaxis

28
Q

What should be considered for treating invasive candidiasis?

A

Aggressive and prolonged anti-fungal therapy based on pt characteristics, clinical status, site of infection, and tx response

29
Q

Approved candidiasis indications of fluconazole

A
  • Oropharyngeal
  • Esophageal
  • Invasive
  • Prophylaxis
30
Q

Approved candidiasis indications of itraconazole

A
  • Oropharyngeal

- Esophageal

31
Q

Approved candidiasis indications of voriconazole

A
  • Esophageal

- Invasive

32
Q

Approved candidiasis indications of posaconazole

A
  • Oropharyngeal

- Prophylaxis

33
Q

What is included in the tx for invasive pulmonary aspergillosis?

A
  • Prompt anti-fungal therapy, source control, consider GCSF/granulocyte infusions
  • Voricon
  • [Ampho B]
  • Secondary prophylaxis w/ voricon or posacon during subsequent immunosuppression
34
Q

Duration of therapy for aspergillosis

A

> 6-12 weeks

35
Q

Tx of blastomycosis

A
  • Mild-moderate = itraconazole 200 mg PO q12h

- Moderate-severe = ampho B x 1-2 weeks (max 2 g) then itraconazole 200 mg PO q12h

36
Q

Duration of therapy for blastomycosis

A

> 6-12 months

37
Q

Spectrum of fluconazole

A
  • C. albicans
  • Less C. glabrata
  • NOT C. krusei
38
Q

Spectrum of itraconazole

A
  • Increased endemic (blastomyces)

- Aspergillus

39
Q

Spectrum of voriconazole

A
  • C. glabrata
  • C. krusei
  • Aspergillus
  • Fusarium
40
Q

Spectrum of posaconazole

A

Mucoralis