Cryptococcal meningitis is a serious infection of the brain and spinal column that can occur in people living with HIV. It is caused by a fungus—Cryptococcus neoformans.
Cryptococcus neoformans is very common in the environment and can be found in soil and in bird droppings. If soil containing Cryptococcus neoformans is kicked up into the air, it can be inhaled and deposited in the lungs. From there, the fungus can travel through the blood to the spinal column and brain where it can cause disease.
While most adults and children have been exposed to this fungus at some point during their lives, they generally have immune systems that are healthy enough to prevent Cryptococcus neoformans from causing disease. At one time, between 5 and 8 percent of people with HIV developed cryptococcal meningitis. Since the introduction of potent combination antiretroviral (ARV) therapy, however, that number has dropped significantly. People with compromised immune systems, particularly HIV-positive people with CD4 cell counts below 50, are more likely to experience cryptococcal meningitis.
Cryptococcal meningitis results in inflammation and swelling of the brain. This can be extremely debilitating and/or painful and can cause damage to the brain. Cryptococcus neoformans can also cause disease in the lungs and, less commonly, in the kidneys, skin, urinary tract, and lymph nodes.
If it is not treated correctly, cryptococcal meningitis can be fatal. Thus, it is very important for HIV-positive people with compromised immune systems to monitor their health closely and report any symptoms to their health-care provider.