Coccidioidomycosis (Coccidioides Species)

Coccidioidomycosis, also known as Valley fever, is a systemic fungal infection endemic to Arizona, California, Texas, other western states in the United States, and other countries throughout the Western Hemisphere. Of an estimated 150,000 US infections per year, a third require medical attention and an even smaller number are accurately diagnosed. Infection is initiated by inhalation of a fungal spore (arthroconidium) arising from endemic soil. In tissue, growth occurs as a spherule that produces endospores that are released and propagate new spherules. Illness, 1 to 3 weeks after infection, most commonly appears as a community-acquired pneumonia and includes skin rashes, musculoskeletal pain, and striking fatigue. Although most illnesses eventually resolve without treatment, they are very debilitating for weeks to many months. A small percentage of patients develop symptomatic fibrocavitary pneumonia or hematogenous spread to other organs, most commonly the skin, the skeleton, and the meninges. These complications necessitate therapy. Diagnosis requires specific laboratory tests, most commonly to detect specific anticoccidioidal serum antibodies. Current therapy most frequently is fluconazole or other oral azole antifungal drugs. Patients with very widespread infection or who are rapidly deteriorating are often treated with amphotericin B initially. Antifungal treatment is not curative, courses of treatment for complicated infections range from a year to many years to lifelong, and discontinuation of treatment often results in relapse. A preventative vaccine does not currently exist, but a vaccine candidate is under development for use in dogs.