Public warned of rise in Valley fever infections across Southern California

Health officials are warning the public as Valley fever cases are increasing across California.

Valley fever, also known as coccidioidomycosis or “cocci,” typically affects the lungs and can cause prolonged respiratory symptoms including cough, fever, chest pain, and fatigue or tiredness, according to The California Department of Public Health.

Valley fever is caused by breathing in a fungus found in dust from outdoor air, CDPH explained. When heavy rains exist for prolonged periods, the fungus can grow and spread into the air.

For some, the symptoms can be severe enough to interrupt daily life including missing work, school, or other activities.

“Research from the University of California, Berkeley and CDPH shows that during drought, the fungus that causes Valley fever can become less active,” officials said. “However, when the rains return, the fungus can grow, leading to increases in infection. Cases of Valley fever in California have historically been lowest during years of drought and highest during years immediately after a drought. The wet winter season California experienced could lead to more Valley fever cases this summer and fall.”

Due to the historic rainfall in Southern California this past winter, health officials are warning the public of the potential increase in infections while sharing ways to distinguish the illness from other ailments.

Valley fever shares many of the same symptoms with other respiratory diseases, including COVID-19, CDPH said.

Symptoms can last a month or more and laboratory tests are needed to determine whether the issue is caused by Valley fever or another illness.

If a COVID-19 test comes back negative, but respiratory symptoms last more than a week, officials advise speaking to a doctor to inquire whether the symptoms could be caused by Valley fever.

“California’s dry conditions, combined with recent heavy winter rains could result in increasing Valley fever cases in the coming months,” said CDPH Director and State Public Health Officer Dr. Tomás Aragón. ”Individuals with lingering cough and fatigue should talk to a health care provider about Valley fever, especially if they have been outdoors in dusty air.”

Valley fever infections continue to be highest in California’s Central Valley and Central Coast regions, including Kern, Kings, San Luis Obispo, Fresno, Tulare, Madera, and Monterey counties.

“However, as the climate changes, Valley fever has increased in other areas of the state as well,” officials said, most notably in Southern California and in the Northern San Joaquin (Central) Valley.

Those most likely to be infected are anyone who participates in outdoor activities involving close contact with dirt or dust. Anyone who lives in areas typically prone to infections is also at risk.

Those with the highest risk of severe symptoms if infected include adults 60 years or older, pregnant women, people with diabetes, cancer, or conditions that weaken the immune system and people who are Black or Filipino, according to the CDPH.

Tips to mitigate Valley fever infections include:

-When it’s windy outside and the air is dusty, stay indoors and keep windows and doors closed.
-Before digging, wet down soil and dirt to prevent stirring up dust into the air.
-Consider wearing a properly fitted N95 mask if you must be in dusty air outdoors in these areas.
-CDPH encourages people who live in, work, or visit areas where Valley fever is common to learn about the signs and symptoms and the ways to help reduce the risk of infection.
-Employers with employees working outdoors in these areas should train workers about Valley fever symptoms and take steps to limit exposure to dust, such as watering down soil before digging.

“About 20,000 Valley fever cases are reported in the U.S. each year, mostly from Arizona and California, and the number of cases is increasing,” officials said.

Infection rates typically reach their peak during the summer and fall months. If Valley fever is diagnosed, your doctor will determine the best course of treatment. For additional information, visit CDPH’s Valley fever website.