The risk of valley fever increases in California after heavy winter rains

After California’s record winter rains, public health officials are warning of an increased risk of valley fever this summer.

“California’s dry conditions combined with recent heavy winter rains may result in increased cases of valley fever in the coming months,” said California Director of Public Health Dr. Tomás Aragón, in a press release.

During a drought, the fungus that causes valley fever is often less active, but it grows when the rains return, according to the Department of Public Health. Valley fever cases have been lowest during droughts and highest in the years immediately following a drought, raising concerns for this summer and fall after the record-breaking rains that hit California.

People and animals can become ill when they inhale dust containing the fungus that causes valley fever, also known as coccidioidomycosis.

(California Department of Public Health)

Valley fever, also known as coccidioidomycosis or “cocci”, is caused by a fungus that grows in dirt. People and animals can become ill if they inhale the dust containing the fungus.

It typically affects the lungs, resulting in symptoms including chest pain, cough, fever and fatigue. Symptoms can last for a month or more.

Because the symptoms overlap with other respiratory illnesses, including COVID-19, laboratory tests may sometimes be needed to determine whether the infection is valley fever. People who test negative for COVID-19 but continue to experience symptoms for more than a week should talk to a doctor.

About 20,000 cases are reported each year in the United States, primarily in California and Arizona. Prices are highest in the Central Coast and Central Valley regions, including Kern, Kings, San Luis Obispo, Fresno, Tulare, Madera and Monterey counties. Several cases have been reported in the northern San Joaquin Valley and southern California over the past few years.

People most likely to be infected are those who live or work in areas with high incidences of the disease and those who have close contact with dirt or dust. Black and Filipino people, adults 60 and older, pregnant women, and people with cancer, diabetes, and conditions that weaken the immune system are at higher risk for severe valley fever.