Cryptococcosis
OVERVIEW
- Cryptococcosis is a fungal infection caused by two different yeast species, that usually manifests as meningitis or pneumonia.
- cryptococcus neoformans meningitis is an AIDS defining illness
ETIOLOGY
- Cryptococcus is distributed worldwide and exists in high concentrations in bird guano, particularly pigeons and chickens (infections do NOT usually involve direct contact with birds)
- Cryptococcus neoformans (two variants – grubei and neoformans; 4 serotypes A-D) -> AIDS and immunocompromised patients
- cryptococcus gattii-> endemic to tropical and subtropical areas, travelers, increasing found in temperate areas
ASSESSMENT
Clinical manifestations (vary with species and serotype)
- meningitis – headache of insidious onset, neck stiffness often absent, fever often late
- other sites involved in AIDS: lungs, bone marrow, skin (often resembles molluscum contagiosum), and genitourinary tract
- C. gattii predominantly causes pneumonia
Investigations
- blood culture
- biopsy lesions
- CXR and/or CT chest (pneumonia)
- CT head (exclude mass lesion)
- CSF (LP must be performed even in the absence of neurological features)
— India ink stain (51% sensitive)
— MCS, high opening pressure, high protein, high WCC (low glucose if severe)
— Cryptococcal latex agglutination test for capsular polysaccharide antigen = 90% sensitive and specific (false positives if rheumatoid factor positive)
COMPLICATIONS
- immune reconstitution inflammatory syndrome (IRIS) with HAART in AIDS patients with Cryptococcal disease
MANAGEMENT
General
- Resuscitation
- supportive care and monitoring
Antimicrobial therapy
- two week induction phase, followed by an 8 week consolidation phase, and then a prolonged maintenance phase thereafter
- induction phase (2 weeks): amphotericin B (0.7 to 1 mg/kg/day) plus flucytosine (100 mg/kg/day)
- consolidation phase (8 weeks): fluconazole 400 mg daily for 8 weeks
- maintenance (at least 12 months): fluconazole (200 mg daily) is recommended once CSF sterilization has occurred
Other specific therapy
- opening pressures greater than 25 cm of CSF should be treated with serial (e.g., daily) lumbar punctures until the pressure normalizes to less than 20 cm of CSF
References and Links
- Chaturvedi V, Chaturvedi S. Cryptococcus gattii: a resurgent fungal pathogen. Trends Microbiol. 2011 Nov;19(11):564-71. PMC3205261.
- Singh N, Dromer F, Perfect JR, Lortholary O. Cryptococcosis in solid organ transplant recipients: current state of the science. Clin Infect Dis. 2008 Nov 15;47(10):1321-7. PMC2696098.
- Warkentien T, Crum-Cianflone NF. An update on Cryptococcus among HIV-infected patients. Int J STD AIDS. 2010 Oct;21(10):679-84. PMC3134968.
- Wiesner DL, Boulware DR. Cryptococcus-Related Immune Reconstitution Inflammatory Syndrome(IRIS): Pathogenesis and Its Clinical Implications. Curr Fungal Infect Rep. 2011 Dec 1;5(4):252-261. PMC3289516.
Critical Care
Compendium
Chris is an Intensivist and ECMO specialist at the Alfred ICU in Melbourne. He is also a Clinical Adjunct Associate Professor at Monash University. He is a co-founder of the Australia and New Zealand Clinician Educator Network (ANZCEN) and is the Lead for the ANZCEN Clinician Educator Incubator programme. He is on the Board of Directors for the Intensive Care Foundation and is a First Part Examiner for the College of Intensive Care Medicine. He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives.
After finishing his medical degree at the University of Auckland, he continued post-graduate training in New Zealand as well as Australia’s Northern Territory, Perth and Melbourne. He has completed fellowship training in both intensive care medicine and emergency medicine, as well as post-graduate training in biochemistry, clinical toxicology, clinical epidemiology, and health professional education.
He is actively involved in in using translational simulation to improve patient care and the design of processes and systems at Alfred Health. He coordinates the Alfred ICU’s education and simulation programmes and runs the unit’s education website, INTENSIVE. He created the ‘Critically Ill Airway’ course and teaches on numerous courses around the world. He is one of the founders of the FOAM movement (Free Open-Access Medical education) and is co-creator of litfl.com, the RAGE podcast, the Resuscitology course, and the SMACC conference.
His one great achievement is being the father of three amazing children.
On Twitter, he is @precordialthump.
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