Diagnosing and assessing cryptococcosis
Chang 2023Chang 2021Chang 2024
Cryptococcosis often presents as a subacute or chronic illness characterised by malaise, fever and weight-loss; site-specific symptoms can also occur. In cryptococcal meningitis, central nervous system (CNS)–based symptoms that may occur include altered mental state, headache, confusion, nausea, vomiting, and visual and hearing impairment. In pulmonary cryptococcosis, respiratory-based symptoms that may occur include cough, shortness of breath, and hoarse voice (in the case of laryngeal cryptococcomas).
Cryptococcus may be suspected based on the symptoms discussed above. It may also be incidentally detected on imaging of the brain or chest, or on culture of blood, sputum or tissue. If cryptococcosis is suspected or confirmed, the following tests should be undertaken:
- serum and cerebrospinal fluid (CSF) cryptococcal antigen
- blood and, if producing sputum, sputum cultures
- chest imaging (computed tomography [CT] with contrast or, if not available, X-ray)
- CNS imaging (magnetic resonance imaging [MRI] brain, or if not available, CT brain with contrast)
- lumbar puncture with measurement of opening pressure and collection of CSF for microscopy, culture and biochemistry – recommended for all patients1.
If cryptococcosis is confirmed, an assessment of the patient’s immune function should be performed. At a minimum, perform the following tests:
- full blood examination
- CD4:CD8 lymphocyte ratio
- HIV antibody/antigen.
Management of cryptococcosis depends on the site of infection. For more information, see cryptococcal meningitis and pulmonary cryptococcosis.