Test Details: Cryptococcus neoformans is a fungus, found in the soil, which produces spores that can be inhaled. The cryptococcal test is used to diagnose any infection with the fungus in the blood. Cryptococcus can cause life-threatening infection in the brain called cryptococcal meningitis. Cryptococcal antigen can be detected in serum in patients with cryptococcal pneumonia or meningitis or other extra-pulmonary site infection, especially in patients with HIV/AIDS.