Fungal meningitis is rare in the United States. It can develop after a fungus spreads from somewhere else in the body to the brain or spinal cord.
Some causes of fungal meningitis include Cryptococcus, Histoplasma, Blastomyces, Coccidioides, and Candida.
Certain fungi that can cause meningitis live in the environment:
- Cryptococcus lives in soil, on decaying wood, and in bird droppings throughout the world.
- Histoplasma lives in environments with large amounts of bird or bat droppings. In the United States, the fungus mainly lives in the central and eastern states.
- Blastomyces lives in moist soil and in decaying wood and leaves. In the United States, the fungus mainly lives in midwestern, south central, and southeastern states.
- Coccidioides lives in the soil in the southwestern United States and areas of Central and South America.
These fungi are too small to see without a microscope. People can get sick if they breathe in fungal spores. People get meningitis if the fungal infection spreads from the lungs to the brain or spinal cord. Fungal meningitis does not spread between people.
The fungus Candida can also cause meningitis. Candida normally lives inside the body and on the skin without causing any problems. However, in certain patients who are at risk, Candida can enter the bloodstream or internal organs and cause an infection.
Although anyone can get fungal meningitis, people with weakened immune systems are at increased risk. Certain health conditions, medications, and surgical procedures may weaken the immune system. HIV infection and cancer are examples of health conditions that can weaken the immune system. Medications that can weaken the immune system include:
- Steroids (such as prednisone)
- Medications given after organ transplantation
- Anti-TNF medications, which are sometimes given for treatment of rheumatoid arthritis or other autoimmune conditions
Premature babies with very low birth weights are also at increased risk for getting Candida bloodstream infection, which may spread to the brain.
Living in certain areas of the United States may increase the risk for fungal lung infections, which can cause meningitis.
Signs and symptoms of fungal meningitis may include the following:
- Stiff neck
- Nausea and vomiting
- Photophobia (eyes being more sensitive to light)
- Altered mental status (confusion)
If a doctor suspects meningitis, he or she may collect samples of blood or cerebrospinal fluid (fluid surrounding the spinal cord). Then laboratories can perform specific tests, depending on the type of fungus suspected. Knowing the cause of fungal meningitis is important because doctors treat different types of fungi differently.
Doctors treat fungal meningitis with long courses of high-dose antifungal medications, often given directly into a vein through an IV. After that, patients also need to take antifungal medications by mouth. The total length of treatment depends on the patient’s immune system and the type of fungus causing the infection. Treatment is often longer for people with weak immune systems, like those with AIDS or cancer.
No specific activities are known to cause fungal meningitis. People with weak immune systems should try to avoid
- Large amounts of bird or bat droppings
- Digging in soil
- Dusty activities
This is especially true if they live in a geographic region where fungi like Histoplasma, Coccidioides, or Blastomyces exist.