Cryptococcosis
Cryptococcosis is a serious fungal infection primarily affecting individuals with compromised immune systems, such as those with HIV/AIDS, and is commonly found in tropical and subtropical regions. It is caused by two fungi, Cryptococcus neoformans and C. gattii, which are typically found in soil and bird droppings. The infection usually begins in the lungs after inhalation of airborne spores, but it can spread to other parts of the body, including the central nervous system, skin, eyes, and bones.
Key risk factors for developing cryptococcosis include exposure to environments rich in bird droppings and soil contaminated with the fungi, particularly for individuals with weakened immunity due to chronic diseases or medication. Symptoms can vary, with lung infections presenting as fever and cough, while central nervous system involvement may lead to meningitis characterized by severe headaches and neck stiffness. Diagnosis often involves physical examinations, imaging tests, and analysis of bodily fluids.
Treatment typically includes antifungal medications, with many patients experiencing resolution of mild symptoms through outpatient care. However, those with AIDS may face more severe symptoms and a higher likelihood of recurrence, highlighting the importance of ongoing treatment and immune system management. Preventative measures focus on avoiding high-risk environments, especially for immunocompromised individuals.
Cryptococcosis
- ANATOMY OR SYSTEM AFFECTED: All
Definition
Cryptococcosis is a serious fungal infection most frequently acquired in tropical and subtropical areas of the world. People with compromised immune function, such as those with human immunodeficiency virus (HIV) infection and acquired immunodeficiency syndrome (AIDS), are often affected.
Causes
Cryptococcosis can be caused by either of two types of fungi Cryptococcus neoformans or C. gattii which are found in soil and bird droppings and in and around tropical trees. Because the fungi enter the body through inhalation of airborne fungal spores, the most common site of infection is the lungs. However, cryptococcosis can develop in any part of the body, including the skin, eyes, central nervous system, and bones.
Risk Factors
Risk factors for cryptococcosis include exposure to areas with a high concentration of bird droppings and to soil or trees contaminated with C. neoformans or C. gattii, in combination with low immunity caused by previous infection, the use of corticosteroids, or chronic disease. People with AIDS are particularly susceptible to cryptococcosis, especially persons with low levels of a particular type of white blood cell, CD4+ T cells. Persons with AIDS who receive ongoing treatment with antiretroviral medications are afforded some protection.
Symptoms
When the lungs are affected, symptoms include fever, cough, shortness of breath, and coughing up blood (hemoptysis). If the central nervous system becomes involved, symptoms of meningitis occur; these include stiff neck, headache, vomiting, and seizures. Skin infection may appear as a rash, swollen area, or blister. Cryptococcosis involving the eyes may cause eye pain and vision loss.
Screening and Diagnosis
A complete physical exam will reveal impaired immunity in combination with symptoms that lend suspicion for cryptococcosis. To confirm the diagnosis, the patient may receive a chest X-ray; routine laboratory testing and culture of skin lesions, blood, urine, or sputum; and a lumbar puncture, which involves aspiration of cerebrospinal fluid for analysis.
Treatment and Therapy
Cryptococcosis is treated with oral or intravenous antifungal medication, such as flucanozole, for about six months. In many patients, symptoms are mild and resolve quickly once treated on an outpatient basis, but persons with AIDS typically have more severe symptoms, require hospitalization, and often experience a recurrence of infection.
Prevention and Outcomes
Avoiding infested tropical and subtropical areas is key to preventing cryptococcosis. Persons with AIDS should be made aware that they may be infected with cryptococcosis more than once because of their suppressed immune systems, but that treatment with antiretroviral medications can increase CD4+ T cell counts and reduce the risk of being infected.
Bibliography
Bennet, John E. “Cryptococcosis.” In Harrison’s Principles of Internal Medicine, edited by Joan Butterton. 17th ed. New York: McGraw-Hill, 2008.
Bellissimo-Rodrigues, Fernando, et al. “Cutaneous Cryptococcosis Due to Cryptococcus gattii in a Patient on Chronic Corticotherapy.” Revista da Sociedade Brasileira de Medicina Tropical 43 (2010): 211-212.
Dromer, Françoise, et al. “Major Role for Amphotericin B-Flucytosine Combination in Severe Cryptococcosis.” PLoS One 3 (2008): e2870.
Jong, Elaine C., and Russell McMullen, eds. Travel and Tropical Medicine Manual. 4th ed. Philadelphia: Saunders/Elsevier, 2008.
Murray, Patrick R., Ken S. Rosenthal, and Michael A. Pfaller. Medical Microbiology. 6th ed. Philadelphia: Mosby/Elsevier, 2009.
Sarosi, George A., and Scott F. Davies, eds. Fungal Diseases of the Lung. 3d ed. Philadelphia: Lippincott Williams & Wilkins, 2000.
"Treatment of Cryptococcosis." Centers for Disease Control and Prevention (CDC), 31 Jan. 2025, www.cdc.gov/cryptococcosis/treatment/index.html. Accessed 2 Feb. 2025.
Webster, John, and Roland Weber. Introduction to Fungi. New York: Cambridge University Press, 2007.