C. neoformans Infection Risk & Prevention

C. neoformans infections are extremely rare among people who are otherwise healthy. Most cases of C. neoformans infection occur in people who have weakened immune systems^1-3, such as people who:

• Have advanced HIV/AIDS,
• Have had an organ transplant, or
• Are taking corticosteroids, medications to treat rheumatoid arthritis, or other medications that weaken the immune system.

No. The infection can’t spread between people or between people and animals.

Yes. Pets can get C. neoformans infections, but it is very rare, and the infection cannot spread between animals and people.^4-5 If you’re concerned about your pet’s risk of getting a C. neoformans infection, or if you think that your pet has the infection, please talk to a veterinarian.

It’s difficult to avoid breathing in C. neoformans because it’s thought to be common in the environment. Most people who breathe in C. neoformans never get sick from it. However, in people who have weakened immune systems, C. neoformans can stay hidden in the body and cause infection later when the immune system becomes too weak to fight it off. This leaves a window of time when the silent infection can be detected and treated early, before symptoms develop (see “Detecting silent cryptococcal infection in people who have HIV/AIDS”).

One approach to prevent cryptococcal meningitis is called "targeted screening." Research suggests that C. neoformans is able to live in the body undetected, especially when a person's immune system is weaker than normal. In a targeted screening program, a simple blood test is used to detect cryptococcal antigen (an indicator of cryptococcal infection) in HIV-infected patients before they begin taking antiretroviral treatment (ART). A patient who tests positive for cryptococcal antigen can take fluconazole, an antifungal medication, to fight off the silent fungal infection and prevent it from developing into life-threatening meningitis.