Disturbing soil increases chances of exposure to spores that cause valley fever.

We’ve all heard about this year’s severe flu season, but there’s another “fever” to be aware of that – while not contagious from person to person – has still been a growing source of concern among California public health officials.

Reported cases of valley fever still continue to increase in areas of California. According to the California Department of Public Health, reported cases increased by more than a third from 5,704 cases in 2016 to over 7,000 in 2017. The San Joaquin Valley, a major hub for the disease, is where more than 75 percent of the state’s cases occur.  

The number of confirmed cases varies from year to year and by season, but factors such as increases in temperature and rainfall can potentially contribute to the rise of valley fever.

Although the fungal infection can be a major irritation for those who contract it, it’s important for all people – regardless of age or health – to be knowledgeable about common associated symptoms and to understand preventable strategies to avoid exposure.  For some populations, valley fever can lead to serious or life-threatening complications.

Here’s what you need to know:

Valley fever is an environmental airborne fungus
The fungal infection is caused by microscopic Coccidioides fungi, pathogenic spores that are found in dry desert-like dirt or soil, usually within the top two to 12 inches. When the ground is disturbed by wind, farming or construction, the spores become airborne and can potentially lead to serious respiratory infection or life-threatening complications in some groups.

Improving valley fever research with fungal diagnostics and genomic sequencing
UC Davis Health clinicians and researchers actively work to develop new approaches for the prevention and treatment of valley fever, while leading research to better understand the affects it has on high-risk groups. The UC Davis Coccidioidomycosis Serology Laboratory in the UC Davis Department of Medical Microbiology and Immunology provides diagnostic and consultative services for suspected or established cases of valley fever.

Anyone can contract valley fever, but some groups have a higher risk
The majority of established cases are predominantly among those who live, work or visit areas that are known to be endemic – where the disease is commonly found. About 10,000 cases are reported each year, mostly from Arizona and California. The infection can create health risks for everyone, especially for members of sensitive groups such as:

  • Adults 60 years or older
  • Pregnant women
  • African Americans, Filipinos, and Hispanics
  • Diabetics
  • People with conditions that weaken the immune system, including those with an organ transplant or who have HIV/AIDS

Valley fever is not contagious, but symptoms can mimic the flu
Sixty percent of those exposed to the fungus don’t develop symptoms at all, or experience mild flu-like symptoms that resolve naturally. Sometimes there can be a delay in diagnosis because the symptoms resemble common illnesses such as the flu and bacterial pneumonia.

A very small proportion of people develop disseminated disease that causes chronic pneumonia, joint pain, fever, fatigue or – in particularly worrisome cases – meningitis, a potentially fatal infection of the membranes and fluid covering the brain and spinal cord.

If you experience any of these symptoms and live in or have visited an area where the fungus is common, ask your doctor to test you for valley fever. The benefit of earlier diagnosis and seeking out care is integral to improvement against the infection.

If you have valley fever, you may need treatment with prescription antifungal medication.

Avoiding exposure can be tough, but prevention is key
There is no vaccine to protect against infection. In areas where valley fever is common, it’s difficult to completely avoid environmental exposure, but there are steps you can take to protect yourself. People with weak immune systems or who are at high risk for developing the severe form of the disease should consider these strategies:

  • Limit activities that involve close contact with dirt such as gardening, yard work and digging.
  • During windy weather conditions, stay inside and keep windows and doors closed.
  • Use air filtration measures while indoors, and the recirculation setting on your air conditioner while driving.
  • Clean skin injuries with soap and warm water to reduce the chances of developing a skin infection, especially if the wound was exposed to dirt or dust.
  • Avoid dusty construction areas or excavation sites. If you live around or work in these conditions, think about wearing a ventilated mask that covers the nose and throat when going outside. Not all masks will be effective, especially regular everyday “dust masks.” The California Department of Health recommends choosing a particulate filter mask with two straps, labeled NIOSH and marked with N95, N99 or P100.

More Resources

Recent UC Davis valley fever findings

Centers for Disease Control and Prevention

California Department of Health

UC Davis Coccidioidomycosis Serology Laboratory

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