Coccidioidomycosis; acute (primary) pulmonary

Alternative names:

San Joaquin Valley fever; valley fever

Definition:

A disease caused by breathing in a fungus found in the soil in certain parts of the southwestern U.S., Mexico, and Central and South America.

Causes, incidence, and risk factors:

Infection is caused by breathing in spores of a fungus, Coccidioides immitis, found in desert regions. About 60% of infections cause no symptoms and are only recognized by a positive coccidioidin skin test. In the remaining 40% symptoms range from mild to severe. Dark-skinned people and people with a weak immune system will have more serious infections. The incubation period is 10 to 30 days. The acute form can develop into widespread disseminated disease or into a chronic pulmonary (lung) disease after a long latent period. Recent travel to or residence in southwestern deserts of the U.S. is a risk factor. The incidence of acute coccidioidomycosis is 1 out of 100,000 people.