Cryptococcal meningitis (krip-toh-KOK-uhl men-in-JEYE-tis) is an infection of the lining of the brain and spinal cord. It is not as common as some other opportunistic infections, but it can be deadly. The fungus that causes this infection is found in soil. The risk is highest when CD4 cell counts are below 100. You can get it by breathing in dust. Symptoms include headache, nausea, fever, fatigue, irritability, sensitivity to light, stiff neck, change in mental state, and hallucinations. Unlike bacterial meningitis, this form comes on more slowly, in a few days to a few weeks. This is a serious infection that can be deadly, so get treatment right away. It is treated with drugs to kill the fungus. You might get an oral drug or an IV drug. Some drugs used to treat it can hurt your kidneys. So, it's best to get treatment early, when there's a chance to use drugs that are less toxic. Even after treatment, the fungus can come back. You might need to take drugs all the time to prevent it from coming back. This form of meningitis only affects people with weak immune systems, like people with AIDS, cancer, or diabetes.