Fungal meningitis facts*
*Fungal meningitis facts medical author: Charles P. Davis, MD, PhD
- Fungal meningitis is rare; the most common cause is Cryptococcus spp. infection, but many other fungi may occasionally cause meningitis.
- Fungal meningitis is not transmitted from person to person. The fungi are usually inhaled and then spread by the blood to the central nervous system; fungi may also be directly inserted into the central nervous system by medical techniques or enter from an infected site near the central nervous system to cause meningitis.
- Risk factors include any disease or treatment that may weaken the immune system, surgical procedures and medications may introduce fungi into the central nervous system, and other factors such as pregnancy or living in areas that have high fungal concentrations in the soil or air increase the risk of fungal meningitis.
- Headache, stiff neck, fever, nausea and vomiting, photophobia, and altered mental status are potential symptoms of fungal meningitis.
- Blood and cerebrospinal fluid are cultured and examined to diagnose fungal meningitis.
- Treatment of fungal meningitis is with IV antifungal drugs; the length of treatments vary with the patient's immune status.
- Although no specific activities are known to cause fungal meningitis, people with immune system problems are advised to avoid areas and geographical regions where soil, dust, or bird droppings may have high fungal contamination.
Fungal meningitis is rare and usually the result of spread of a fungus through blood to the spinal cord. Although anyone can get fungal meningitis, people with weakened immune systems, like those with HIV infection or cancer, are at higher risk.
The most common cause of fungal meningitis for people with weakened immune systems is Cryptococcus. This disease is one of the most common causes of adult meningitis in Africa.
Fungal meningitis is not contagious, which means it is not transmitted from person to person. Fungal meningitis can develop after a fungus spreads through the bloodstream from somewhere else in the body, as a result of the fungus being introduced directly into the central nervous system, or from an infected body site infection next to the central nervous system.
You may also get fungal meningitis after taking medications that weaken your immune system. Examples of these medications include steroids (such as prednisone), medications given after organ transplantation, or anti-TNF medications, which are sometimes given for treatment of rheumatoid arthritis or other autoimmune conditions.
Different types of fungus are transmitted in several ways. Cryptococcus is thought to be acquired through inhaling soil contaminated with bird droppings, and Histoplasma is found in environments with heavy contamination of bird or bat droppings, particularly in the Midwest near the Ohio and Mississippi Rivers. Blastomyces is thought to exist in soil rich in decaying organic matter in the Midwest United States, particularly the northern Midwest. Coccidioides is found in the soil of endemic areas (Southwestern US and parts of Central and South America). When these environments are disturbed, the fungal spores can be inhaled. Meningitis results from the fungal infection spreading to the spinal cord. Candida is usually acquired in a hospital setting.
Meningitis Symptoms and Signs
The classic signs and symptoms of meningitis are headache, fever, and stiff neck (in adults and older children). Symptoms of meningitis may appear suddenly and can also include nausea and vomiting. Changes in behavior, such as confusion, sleepiness, and difficulty waking up, are other important symptoms. In infants, symptoms of meningitis are often much less specific and may include irritability or tiredness, poor feeding, and fever.
Certain diseases, medications, and surgical procedures may weaken the immune system and increase your risk of getting fungal infection, which can lead to fungal meningitis. Premature babies with very low birth weights are also at increased risk for getting Candida blood stream infection, which may spread to the brain.
Living in certain areas of the United States may increase your risk for fungal lung infections, which can also spread to the brain. For example, bird and bat droppings in the Midwestern United States may contain Histoplasma, and soil in the Southwestern United States may contain Coccidioides.
African Americans, Filipinos, pregnant women in the third trimester, and people with weakened immune systems are more likely to get Coccidiodes infection, which is also called valley fever.
Signs and Symptoms
Signs and symptoms of fungal meningitis may include the following:
If meningitis is suspected, samples of blood or cerebrospinal fluid (near the spinal cord) are collected and sent to a laboratory for testing. Knowing the specific cause of meningitis is important because the severity of illness and the treatment will differ depending on the cause.
To confirm fungal meningitis, specific lab tests can be performed, depending on the type of fungus suspected.
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Fungal meningitis is treated with long courses of high dose antifungal medications, usually given through an IV line in the hospital. The length of treatment depends on the status of the immune system and the type of fungus that caused the infection. For people with immune systems that do not function well because of other conditions, like AIDS, diabetes, or cancer, treatment is often longer.
No specific activities are known to cause fungal meningitis. Avoid soil and other environments that are likely to contain fungus. People with weakened immune systems (for example, those with HIV infection) should try to avoid bird droppings and avoid digging and dusty activities, particularly if they live in a geographic region where fungi like Histoplasma, Coccidioides, or Blastomyces species exist. HIV-infected people cannot completely avoid exposure.