What is cryptococcal meningitis?

Meningitis is an infection and inflammation of the meninges, which are the membranes that cover the brain and spinal cord. Meningitis can be caused by different germs, including bacteria, fungi, and viruses.

Two types of fungus can cause cryptococcal meningitis (CM). They are called Cryptococcus neoformans (C. neoformans) and Cryptococcus gattii (C. gattii). This disease is rare in healthy people. CM is more common in people who have compromised immune systems, such as people who have AIDS.

The symptoms of CM usually come on slowly. Within a few days to a few weeks of contact, an infected person may develop the following symptoms:

In some cases, the infected person may experience a stiff neck and fever.

If left untreated, CM may lead to more serious symptoms, such as:

Untreated, CM is fatal, especially in people with HIV or AIDS. According to the British Medical Bulletin, 10 to 30 percent of people with HIV-related CM die from the illness.

A fungus called C. neoformans causes most cases of CM. This fungus is found in soil all over the world. It’s usually found in soil that contains bird droppings.

C. gattii also causes CM. It isn’t found in bird droppings. It’s associated with trees, most commonly eucalyptus trees. It grows in the debris around the base of the eucalyptus tree.

CM usually occurs in people who have a compromised immune system. C. gattii is more likely to infect someone with a healthy immune system than C. neoformans. But the conditional rarely occurs in someone who has a normal immune system.

Your doctor will also perform a physical examination when trying to figure out if you have CM. They’ll look for the symptoms associated with this disease.

If your doctor suspects you have CM, they will order a spinal tap. During this procedure, you’ll lie on your side with your knees close to your chest. Your doctor will clean an area over your spine, and then they’ll inject numbing medication.

Your doctor will insert a needle and collect a sample of your spinal fluid. A lab will test this fluid to find out if you have CM. Your doctor may also test your blood.

You’ll receive antifungal drugs if you have CM. The most common choice is amphotericin B. You’ll need to take the drug daily. Your doctor will monitor you closely while you’re on this drug to watch for nephrotoxicity (meaning the drug can be toxic to your kidneys). You’ll typically receive amphotericin B intravenously, meaning directly into your veins.

You’ll probably also take flucytosine, another antifungal medication, while you’re taking the amphotericin B. This combination helps treat the condition quicker.

You’ll need to get spinal fluid testing repeatedly during treatment. If your tests come back negative for CM for two weeks, your doctor will probably ask you to stop taking amphotericin B and flucytosine. You’ll probably switch to taking only fluconazole for about eight weeks.

Most people who develop CM already have severely compromised immune systems. According to the U.S. Centers for Disease Control and Prevention (CDC), infections by C. neoformans occur yearly in about 0.4 to 1.3 cases per 100,000 people in the general healthy population.

However, in patients with HIV or AIDS, the yearly incidence rate is between 2 and 7 cases per 1,000 people. It’s far more common in people with HIV or AIDS patients in Sub-Saharan Africa, where people with this disease have a mortality rate that’s estimated to be 50 to 70 percent.

In many cases, people need to continue taking fluconazole indefinitely. This is especially true in people who have AIDS. Taking this medication helps prevent relapses.