Diseases & Conditions



What is coccidioidomycosis? Coccidioidomycosis, also known as Valley Fever, is a fungal disease caused by Coccidioides species. These organisms live in the soil of semiarid areas. It is endemic in areas such as the southwestern United States, parts of Mexico and South America. It is a reportable disease in states where the disease is endemic, such as California, New Mexico, Arizona and Nevada. Of people who live in an endemic region, about 10-50% will have evidence of exposure to Coccidioides. Who gets coccidioidomycosis? Most of the people who get the disease are people who live in or visit places where the fungus is in the soil and who engage in activities that expose them to dust (such as construction, agricultural work, military field training and archeological exploration). How do coccidioidomycosis infections spread? People get infected with Coccidioides by inhaling fungal spores that become airborne after disturbance of contaminated soil by humans or natural disasters (e.g., dust storms and earthquakes). Is coccidioidomycosis contagious? No, the infection is not spread from person to person, or from animals to people. The infectious form of the fungus exists when the fungus grows in the environment. The fungus changes its form when it infects a person, and this form cannot be transmitted from one person to another. It is important to note, however, that Coccidioides growing in culture as a mold in the laboratory may cause infection in laboratory personnel if the cultures are not handled properly and the appropriate precautions are not taken. What should I do if I have been exposed to Coccidioides in the laboratory? There are currently no guidelines about Coccidioides exposure in the laboratory. If you are concerned that you have had a laboratory-based exposure, you should immediately contact the Occupational Health and/or Infection Control Departments for the laboratory where the exposure occurred. If you are not able to contact Occupational Health or Infection Control, or your laboratory does not have these services, then you should contact your local city, county, or state health department. There are no data to say whether taking an antifungal drug to prevent infection after an exposure helps or not. What are the symptoms of coccidioidomycosis? About 60% of infections do not cause any symptoms. People who develop symptoms may experience a flu-like illness, with fever, cough, headache, rash and muscle aches. Most people make a full recovery, within weeks to months of symptom onset, but a small number of people may develop chronic pulmonary infection or widespread disseminated infection. When the infection spreads outside of the lungs, it most commonly results in skin lesions, central nervous system infection, such as meningitis, and bone and joint infection. Some people are at increased risk for developing disseminated infection: people of African-American, Asian or Filipino descent appear to be at increased risk, as do pregnant women during the third trimester and immunocompromised persons. How soon do symptoms appear? Symptoms may appear between 1-3 weeks after exposure. If I have symptoms, should I see my doctor? Yes, you should see your doctor. How is coccidioidomycosis diagnosed? There are a number of different ways to diagnose the infection. Your doctor may take a specimen of blood or other body fluid to look for antibodies against the fungus that causes coccidioidomycosis (called a “serological” test). Another way to diagnose coccidioidomycosis is to do a biopsy of the affected tissue. The tissue can be examined under a microscope to look for the fungus. A culture of tissue or body fluids can also be performed. How is coccidioidomycosis treated? Symptoms from the acute infection may resolve on their own without treatment. However, some doctors prefer to prescribe antifungal drugs, such as fluconazole, to treat patients with acute, uncomplicated coccidioidomycosis. There is not enough information about whether treating acute, uncomplicated pulmonary coccidioidomycosis is beneficial or not, although many experts feel that persons at risk for developing severe disease should receive treatment. Antibacterial drugs do not treat coccidioidomycosis. In more severe infections, treatment with antifungal drugs is necessary. People who have pneumonia from coccidioidomycosis affecting both lungs, people who have disseminated disease, and people who have chronic pneumonia all need treatment. How can coccidioidomycosis infections be prevented? Avoidance of dusty environments in endemic regions may help to prevent infection. In addition, persons at risk for severe disease should avoid activities that may result in dust exposure, such as digging. Have there been any recent outbreaks? If you live in an endemic area, such as Arizona or the San Joaquin Valley area of California, contact your local or state health department for the most up-to-date information. Outbreaks of coccidioidomycosis do occasionally occur, particularly following earthquakes or other events that disturb large amounts of soil in endemic regions. More recent outbreaks have occurred among military trainees and among archeological workers.