What is the Cryptococcus Antigen (CrAg) Test?

The Cryptococcus Antigen (CrAg) Test is a highly sensitive laboratory test that detects antigens released by the fungi Cryptococcus neoformans and Cryptococcus gattii. It is widely used for the early diagnosis of cryptococcal meningitis and other invasive cryptococcal infections. The test is especially valuable for people with weakened immune systems, such as individuals living with HIV/AIDS, organ transplant recipients, or patients receiving immunosuppressive therapy.

Who should take this test?

• Individuals with suspected cryptococcal meningitis.
• People living with HIV/AIDS, especially with low CD4 counts.
• Organ transplant recipients or patients on immunosuppressive therapy.
• Individuals with persistent fever, severe headache, neck stiffness, or confusion.
• Patients with suspected fungal infections affecting the lungs or central nervous system.
• Doctor-recommended evaluation for invasive cryptococcal infection.

Preparation & Test Process

Understanding Your Results

Positive Cryptococcal Antigen indicates the presence of Cryptococcus infection and requires prompt medical evaluation and treatment.

Negative results suggest that cryptococcal antigen was not detected. However, if symptoms strongly suggest infection, additional testing may be required.

Results should always be interpreted together with your symptoms, physical examination, immune status, CSF findings, fungal culture, and imaging studies when appropriate.

FAQs – Cryptococcus Antigen (CrAg) Test