Cryptococcosis is an infection caused by the fungus Cryptococcus neoformans or Cryptococcus gattii.
People may have no symptoms or may have headache and confusion, a cough and an achy chest, or a rash, depending on where the infection is.
The diagnosis is based on culture and examination of tissue and fluid samples.
Antifungal medications are given by mouth or, if the infection is severe, intravenously.
(See also Overview of Fungal Infections.)
Cryptococcus neoformans occurs primarily in soil that is contaminated with bird droppings, particularly those of pigeons. Cryptococcus gattii usually is present in certain species of trees. These fungi are found all over the world. Unlike Cryptococcus neoformans, Cryptococcus gattii is not associated with birds.
Outbreaks of Cryptococcus gattii have occurred in the Canadian province of British Columbia, the U.S. Pacific Northwest, Papua New Guinea, northern Australia, and in the Mediterranean region of Europe.
Cryptococcus infection was relatively rare until the AIDS epidemic began. Cryptococcosis is a defining opportunistic infection for people with AIDS.
The fungus tends to infect people who have a weakened immune system, including those with the following:
Hodgkin lymphoma or another lymphoma
Use of medications that suppress the immune system, such as those used to prevent rejection of an organ transplant and, when taken for a long time, corticosteroids
However, cryptococcosis caused by Cryptococcus gattii can also develop in people with a normal immune system. It is also more likely to occur in people who have other lung disorders, are 50 years old or older, or smoke tobacco.
Infection usually occurs when people inhale the spores of the fungus. Thus, cryptococcosis typically affects the lungs. It most commonly spreads to the brain and tissues covering the brain and spinal cord (meninges), resulting in meningitis.
Cryptococcosis may also spread to the skin and other tissues, such as the bones, joints, liver, spleen, kidneys, and prostate.
Symptoms of Cryptococcosis
Cryptococcosis usually causes mild and vague symptoms. Other symptoms vary depending on where the infection is:
Lung infection: No symptoms in some people, a cough or an aching chest in others, and, if the infection is severe, difficulty breathing
Meningitis: Headache, blurred vision, depression, agitation, and confusion
Skin infection: A rash, consisting of bumps (sometimes filled with pus) or open sores
Lung infection is rarely dangerous. Meningitis is life threatening.
Diagnosis of Cryptococcosis
Culture and examination of a sample of tissue or fluid
To diagnose cryptococcosis, a doctor takes samples of tissue and body fluids, such as cerebrospinal fluid, sputum, urine, and blood, to be cultured and examined. A spinal tap (lumbar puncture) is done to obtain cerebrospinal fluid (the fluid that surrounds the brain and spinal cord).
Blood and cerebrospinal fluid may be tested for certain substances released by Cryptococcus.
Treatment of Cryptococcosis
Antifungal medications
Antifungal medications are usually used to treat cryptococcosis.
People with a healthy immune system
If the infection affects only a small part of lung and does not cause any symptoms, usually no treatment is needed. However, some doctors prefer to always treat cryptococcosis. Fluconazole is given by mouth to shorten the duration of the illness and reduce the risk of the infection spreading.
If a lung infection causes symptoms, fluconazole is given by mouth for 6 to 12 months.
For people with meningitis, treatment is amphotericin B, given intravenously, followed byfluconazole, given by mouth, for many months.
For people without meningitis, treatment is typically with fluconazole for 6 to 12 months.
For people with an infection in the skin, bone, or other sites, treatment is usually with fluconazole given by mouth. If the infection is severe, people are given amphotericin B intravenously, plus flucytosine andfluconazole, given by mouth.
People with a weakened immune system
People with a weakened immune system always require treatment.
Mild to moderate lung infection may be treated with fluconazole given by mouth for 6 to 12 months.
Severe lung infection or meningitis may be treated with amphotericin B, given intravenously, plus flucytosine, followed by fluconazole, both given by mouth.
After cryptococcosis is treated, people with AIDS usually need to continue taking an antifungal medication (such as fluconazole) until theirCD4 count (the number of one type of white blood cell that decrease when AIDS is uncontrolled) is more than 150 cells per microliter of blood.
