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Valley fever

Valley Fever Basics

What is Valley fever?

Valley fever (also called coccidioidomycosis or “cocci”) is a disease caused by the Coccidioides fungus that grows in the soil and dirt in some areas of California and the southwestern United States. This fungus can infect the lungs and cause respiratory symptoms, including cough, difficulty breathing, fever, and tiredness or fatigue. In rare cases, the Valley fever fungus can spread to other parts of the body and cause severe disease – this type of Valley fever is less common and is called disseminated Valley fever.

Valley fever can be serious and even fatal. Each year in California, there are around 80 deaths from Valley fever and more than 1,000 people are hospitalized with it.

Did you know?

In California, the number of reported Valley fever cases has greatly increased in recent years. Since 2000, the number of cases has increased from less than 1,000 cases to more than 9,000 cases in 2019.

How do you get Valley fever?

You can get Valley fever by breathing in dust from outdoor air that contains spores of the Coccidioides fungus that grows in the soil. Like seeds from a plant, a fungus grows and spreads from tiny spores that are too small to see. When soil or dirt is stirred up by strong winds or while digging, dust containing these fungus spores can get into the air. Anyone who lives, works, or travels in an area where the Valley fever fungus grows can breathe in these fungus spores from outdoor dust without knowing it and become infected. Valley fever is not contagious, meaning it cannot spread from one person or animal to another.

Animals, including pets, can also get Valley fever.

Animals, including pets, can also get Valley fever by breathing in fungus spores from dirt and outdoor dust.

 Where can you get Valley fever?

Most cases of Valley fever in California (over 65%) are reported from the Central Valley and Central Coast regions. People are more likely to get Valley fever if they live, work, or travel in these areas or travel to other places where Valley fever has been reported. There is no commercial test available to see if the Valley fever fungus is in the dirt or dust in certain areas, but we do know that Valley fever has been diagnosed in people living throughout California. The map below shows the rates (or number of cases per 100,000 population) of reported Valley fever cases by county in California from 2014 to 2018.

Valley fever is on the rise in California. Rates are highest in the Central Valley and Central Coast areas

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