Valley Fever (or Coccidioidomycosis) is an infection caused by inhalation of spores of the fungus, Coccidioides, which lives naturally in the soil. It is highly endemic in Arizona and some areas of California, including San Luis Obispo County, Monterey County and the Central Valley region.
Although the fungus that causes Valley Fever can live anywhere in our county, many local cases are from the northern part of the county where conditions are especially dry and windy. When this soil is disturbed—by wind, construction, or other causes—people can breathe in the spores from this fungus and develop Valley Fever.
While many people do not experience symptoms of Valley Fever, it can cause serious complications for some people. More than 60 percent of people who become infected with Valley Fever do not experience any symptoms and do not need treatment. Around 30-40 percent of people develop sudden flu-like symptoms. Most of these people get well on their own within weeks. A small percentage—between one and five percent—will experience a much more serious form of the disease in which the infection spreads throughout the body. People who experience this serious form of Valley Fever are at risk of dying from complications of the disease and may need to take medication for the rest of their lives. Some people are more at risk for this serious form of the disease, including people with compromised immune systems (including people with HIV/AIDS, people currently on chemotherapy, women who are pregnant, and others) and people of African and Asian-Pacific descent.
For more information, see the San Luis Obispo County Valley Fever incidence map, view Public Health's report or pamphlet, or select any of the frequently asked questions below.
Frequently Asked Questions
The most common symptoms are described as flu-like. They include cough, fever, headache, chills, sweats, chest pain, and feeling extra tired. Other symptoms that occur with Valley Fever include rashes on the lower legs and joint pain similar to arthritis. The severity of the symptoms is likely related to the number of spores inhaled.
When chest X-rays are performed on persons with Valley Fever, they typically show fluid in the one or both lungs, glands behind the lungs enlarged, or fluid built up around the lungs.
Unless you have already had Valley Fever, you are at risk of getting this disease by living, working, playing, or passing through an area where the fungus is growing. This includes many parts of San Luis Obispo County.
Many factors can influence the risk of acquiring Valley Fever. Factors which increase the chance of catching Valley Fever include:
- Length of time that you have been living in San Luis Obispo County (longer times increase risk)
- Duration of time spent in dusty conditions (the longer the exposure, the greater the risk)
- Being caught in a dust storm
- Activities that involve intensive contact with undisturbed soils
- Duration of time spent outdoors
- Certain professions
- Time of year (typically, the risk of catching Valley Fever begins to increase in June and continues an upward trend until it peaks during the months of August, September and October)
- Risk for males is 1.4 times higher than for females
- Risk for persons age 15 to 44 is 1.6 times higher than for all other age groups combined
- Area of the county where you live, work or play (the NE corner of the county has the highest number of cases)
Some people are more at risk for the serious form of the disease, including people with compromised immune systems (including people with HIV/AIDS, people currently on chemotherapy, women who are pregnant, and others) and people of African and Asian-Pacific descent.
- Avoid being outdoors during windy conditions.
- Avoid activities in which large amount of dust are generated.
- Minimize exposed soil by using hard ground cover or planting ground cover vegetation.
- Keep disturbed soil wet especially when working directly with the soil.
- Whenever possible provide filtered and conditioned air to living and work spaces.
- Seek prompt medical advice if flu or respiratory illness symptoms occur within a few weeks following exposure to areas where Valley Fever is in the soil.
To report a case of Valley Fever, use this form.
If you experience flu-like symptoms for more than several weeks and suspect you have been exposed to Valley Fever, tell your healthcare provider and ask to be tested for Valley Fever.
No. Once a person becomes infected with Valley Fever they cannot pass the fungus on to anyone else.
View our Epidemiologic Profile to get a comprehensive look at Valley Fever from 1996 - 2012.