Cryptococcosis screening
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Cryptococcosis Microchapters |
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Diagnosis |
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Treatment |
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Cryptococcosis screening On the Web |
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American Roentgen Ray Society Images of Cryptococcosis screening |
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Risk calculators and risk factors for Cryptococcosis screening |
Overview
Screening
- Early studies demonstrated that asymptomatic cryptococcal antigenemia can be detected in up to 12% of patients with HIV/AIDS in endemic regions.
- Cryptococcus neoformans was also demonstrated by direct microscopy and culture in the cerebrospinal fluid of approximately 2/3 of patients.
- Further studies conducted in endemic regions in Africa (South Africa, Uganda) demonstrated that asymptomatic cryptococcal antigenemia ranged from 7 to 38%.
- Asymptomatic antigenemia was also demonstrated to be an independent predictor of mortality among these patients, and, during the first year of ART, an antigen titer greater than 1:8 was 100% sensitive and 96% specific for predicting the incidence of cryptococcal meningitis.
- These alarming findings raised a question about the possibility of developing screening programs among high risk HIV/AIDS patients, and providing patients with fluconazole prophylaxis the decrease the risk of active infections.
- Concerns about the cost effectiveness and efficacy of screening and subsequent prophylaxis have not been addressed in adequately designed and powered studies.
- The limited body of evidence suggests that screening and treatment reduces the incidence of cryptococcal meningitis and death in persons with AIDS.[1]
Methods of Screening
- The majority of studies on cryptococcal screening have used cryptococcal antigen also know as CrAg.[1]
- New point-of-care methods for detecting CrAg have been developed.
- A dipstick test that requires a small blood sample can detect silent antigenemia with high sensitivity in less than 10 minutes and for a small cost (less than $2) has been introduced in 2014.[2][3]
Recommendations
- Given that the efficacy of such an approach has not been thoroughly studied, the IDSA does not recommend routine screening for asymptomatic antigenemia in HIV-infected patients in the United States and Europe.
- However, the IDSA recommends that areas with limited HAART availability, high levels of antiretroviral drug resistance, and a high burden of disease should consider it.
- In the case of asymptomatic antigenemia, a lumbar puncture and a blood culture are recommended.
- Positive results should warrant treatment as symptomatic meningoencephalitis and/or disseminated disease if any signs/symptoms are present.
- However, without evidence of meningoencephalitis, patients should be treated with fluconazole 400 mg PO qd.
Click here to learn more about the regimens used for the treatment of symptomatic meningoencephalitis and/or disseminated disease.
References
- ↑ 1.0 1.1 Kaplan JE, Vallabhaneni S, Smith RM, Chideya-Chihota S, Chehab J, Park B (2015). "Cryptococcal antigen screening and early antifungal treatment to prevent cryptococcal meningitis: a review of the literature". J Acquir Immune Defic Syndr. 68 Suppl 3: S331–9. doi:10.1097/QAI.0000000000000484. PMID 25768872.
- ↑ Preventing Deaths Due to Cryptococcus with Targeted Screening. Centers for Disease Control and Prevention (2015). http://www.cdc.gov/fungal/diseases/cryptococcosis-neoformans/screening.html. Accessed on December 20, 2015
- ↑ Kabanda T, Siedner MJ, Klausner JD, Muzoora C, Boulware DR (2014). "Point-of-care diagnosis and prognostication of cryptococcal meningitis with the cryptococcal antigen lateral flow assay on cerebrospinal fluid". Clin Infect Dis. 58 (1): 113–6. doi:10.1093/cid/cit641. PMC 3864499. PMID 24065327.