Cryptococcal Meningitis: Sensitivity and Specificity

Introduction: Cryptococcal meningitis is caused by Cryptococcus neoformans and typically causes extremely high intracerebral pressures. Note that the serum antigen test is sensitive for AIDS patients only.

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The sensitivity and specificity of findings for Cryptococcal Meningitis are listed below. See the left navigation bar to change the display.

Sensitive and Specific Findings

Cryptococcal Antigen in CSF

93%

at least 93% sensitivity and specificity (depending on the kit), versus culture as gold standard

similar sensitivity numbers from different series, across host types (see second reference)

Study: J Clin Microbiol. 1994;32(7):1680-4. PMID 7929757

J Clin Microbiol. 2005 Nov;43(11):5828-9. PMID: 16272534

Sensitive Findings

Cryptococcal Antigen in Serum
Duplicate

99%

83.3%

in AIDS patients!

Specificity is from the first reference, which gives a sensitivity of only 91%.

Study: J Med Assoc Thai. 1999;82(1):65-71. PMID 10087741

J Clin Microbiol. 2005 Nov;43(11):5828-9. PMID: 16272534

Cryptococcal Antigen in Serum
Duplicate

Sensitivity = 87%

non-HIV immunocompromised. No data for immunocompetent hosts.

Study: J Clin Microbiol. 2005 Nov;43(11):5828-9. PMID: 16272534

Poorly Diagnostic Findings

India Ink stain of CSF

Sensitivity = 75%

in AIDS patients. sensitivity is 50% in non-AIDS patients

Study: UpToDate, references PMID 3299095 and PMID 4811791

Non-contrast Head CT

Sensitivity = 17%

abnormal findings include cryptococcomas and hydrocephalus. these were more common in non-AIDS and especially immunocompetent hosts.

Study: Clin Infect Dis. (2000) 31 (2): 499-508. http://cid.oxfordjournals.org/content/31/2/499.long