The latest California numbers suggest 2025 will be another record-smashing year for valley fever, the illness linked to drought and precipitation and spread by fungal spores.<\/p>\n
There were 6,761 cases reported through the end of July, according to state health officials<\/a> \u2014 a significant increase over the 10-year average of 3,833 for that same time period and a slight jump from last year\u2019s total of 6,364. The 10-year low was in 2016, when there was less than a quarter of what there is now. <\/p>\n Last year\u2019s total of nearly 12,500 cases<\/a> is the most on record for California and far more than the 7,000 to 9,000 cases per year the state averaged between 2016 and 2024.<\/p>\n \u201cCalifornia had a record year for Valley fever in 2024 and, so far, case counts are high in 2025. Valley fever is a serious illness that\u2019s here to stay in California,\u201d said Erica Pan, director of the state public health department. <\/p>\n Officials say the current count is likely to be revised upward as there are often delays in reporting. <\/p>\n Valley fever is most prevalent in the San Joaquin Valley and southern part of the state where the fungus, Coccidioides, thrives in dry, arid soil. Case numbers are also climbing in the northern Central Valley, though, and along the state\u2019s Central Coast.<\/p>\n Researchers speculate<\/a> the rise is tied to patterns of drought and precipitation. Periods of severe drought followed by wet winter and dry summer seem to coincide with more people getting sick.<\/p>\n They also suspect climate change has expanded the fungi\u2019s range<\/a> into areas where it was previously rare. For instance, since 2023, Monterey County\u2019s case numbers have exploded<\/a>. There were 47 cases in 2023 and 348 this year as of July 31. <\/p>\n Cases also doubled since 2023 in Contra Costa, Fresno, San Luis Obispo and Merced<\/a> counties. <\/p>\n People contract Valley fever by inhaling the Coccidioides spores, released when wind, wildfire, tractors, bulldozers, digging or even dancing disturbs the soil. <\/p>\n