Coccioioides infection begins in the lungs, following inhalation of the spores. About 60% of infections resolve without ever causing symptoms and are only recognized by a positive coccidioidin skin test.
In the remaining 40% of infections, symptoms range from mild (such as cold-like or flu-like symptoms) to severe, such as pneumonia. In less than one percent of infections, widespread disease occurs when the fungus spreads from the lungs through the blood stream to involve the skin, bones, joints, lymph nodes, and central nervous system or other organs.
Individuals of African or Philippine descent and people with a weak immune system, such as patients with AIDS or diabetes or those taking immunosuppressive medications, can develop more serious infections. Occasionally the acute infection can develop into a chronic pulmonary (lung) disease or can "reactivate" after a long latent period.
A history of travel to an endemic region is the key to suspecting coccidioidal infection. Arizona, California (especially San Joaquin Valley), and to a lesser extent western Texas are endemic regions in the USA.
|