Coccidiosis
Coccidiosis is a disease caused by the fungi Coccidioides immitis or C. posadasii, primarily affecting the lungs and potentially spreading throughout the body. Commonly referred to as valley fever, it is endemic in regions such as California, Arizona, and parts of Central and South America, where individuals may inhale the fungus when soil is disturbed. The disease presents with nonspecific symptoms, including cough, fever, chills, joint pain, and fatigue, which can be mistaken for viral illnesses. While most cases resolve without treatment, severe infections are more likely in older adults and those with compromised immune systems, leading to complications such as pneumonia or disseminated infections.
Diagnosis involves clinical evaluation, chest X-rays, and antibody testing, with more severe cases potentially requiring bronchoscopy for further assessment. Treatment typically includes antifungal medications for those at higher risk or experiencing severe symptoms, with treatment duration ranging from three months to several years in chronic cases. Preventive measures focus on minimizing dust exposure in endemic areas, and while no vaccine currently exists for humans, research is ongoing. Awareness and understanding of coccidiosis are crucial for those living in or visiting affected regions.
Coccidiosis
- ANATOMY OR SYSTEM AFFECTED: Lungs, respiratory system
- ALSO KNOWN AS: California disease, coccidioidomycosis, desert rheumatism, disseminated valley fever, valley fever
Definition
Coccidiosis is a group of diseases caused by the fungi Coccidioides immitis or C. posadasii.
Causes
Residents of California, Arizona, Mexico, and parts of Central America and South America are most likely to acquire coccidiosis. People usually inhale the fungus when soil is disturbed. Coccidioides primarily affects the lungs and spreads through the body through the lymphatic system or bloodstream, leading to infection throughout the body.
Risk Factors
Activities that increase exposure to dust in endemic areas increase the risk of coccidiosis. Severe infection can occur in people fifty years of age and older, those who have acquired immunodeficiency syndrome, cancer, or diabetes mellitus, and persons who smoke cigarettes, are pregnant, or take medications that suppress the immune system.
Symptoms
Symptoms are nonspecific. Cough, fever, chills, night sweats, joint pain, and fatigue are often mistaken for a viral illness. Most symptoms resolve within several weeks, even without treatment. Occasionally, lung infection leads to pneumonia, manifested as a lung infiltrate on a chest X-ray. People with weakened immune systems are more likely to present with an infection that spreads to the skin, lymph nodes, joints, bones, or brain.
Screening and Diagnosis
People who have symptoms of valley fever should consult a physician for evaluation. A chest X-ray may show localized or diffuse lung infiltrates. Positive antibody testing against Coccidioides confirms coccidiosis. People with more severe lung infections may require a bronchoscopy, a procedure in which a fiber optic scope is inserted into the airways. The specimens can be sent for culture and histopathology to identify Coccidioides on special growth media and to look at lung tissue under the microscope.
Treatment and Therapy
For most people, coccidiosis resolves spontaneously. However, people with risk factors for disseminated infection and those with more severe lung infections are more likely to benefit from treatment. Antifungal drugs such as fluconazole or itraconazole are given for three to six months. Disseminated infections may benefit from intravenous antifungal medications like amphotericin B. For patients with chronic infections, treatment can last years.
Prevention and Outcomes
People who live in endemic areas should avoid activities that expose them to dust. There is no vaccine against Coccidioides, but one has been in development. A vaccine for canines has been developed and is awaiting approval by the US Food and Drug Administration.
Bibliography
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