2019 Valley Fever Cases Exceeded Official Numbers

TOPLINE:

Coccidioidomycosis, or valley fever, constituted a considerable public health burden, with surveillance data capturing only a fraction of actual cases. In 2019, the true annual incidence was approximately 10-18 times higher than reported cases, totaling an estimated 273,000 cases and 900 coccidioidomycosis-related deaths nationwide.

METHODOLOGY:

• Researchers assessed the annual burden of symptomatic coccidioidomycosis in the US using data reported to the National Notifiable Diseases Surveillance System (NNDSS) from January 1, 2019, to December 31, 2019, as inputs for their models.
• The analysis used multipliers from US public health surveillance that accounted for healthcare-seeking behavior, underdiagnosis, underreporting, and in-hospital mortality, based on literature review and expert opinion.
• Regional estimates were generated by categorizing states as high-endemic states (Arizona and California), low-endemic states (Nevada, New Mexico, Texas, Utah, and Washington), or states with unknown endemicity (all other states and Washington, DC).

TAKEAWAY:

• An estimated 273,000 incident symptomatic coccidioidomycosis cases (95% credible interval [CrI], 206,000-360,000) occurred in 2019, with high-endemic states accounting for 125,000 cases (95% CrI, 94,000-165,000).
• The national incidence was calculated as 83 cases per 100,000 people (95% CrI, 63-110), with regional rates of 267 per 100,000 in high-endemic states, 102 per 100,000 in low-endemic states, and 44 per 100,000 in states with unknown endemicity.
• An estimated 23,000 coccidioidomycosis-associated hospitalizations (95% CrI, 18,000-28,000) occurred nationwide, with high-endemic states accounting for 12,000 cases (95% CrI, 10,000-14,000).
• Approximately 900 coccidioidomycosis-related deaths (95% CrI, 700-1100) were estimated nationwide in 2019.

IN PRACTICE:

“Increased awareness nationwide is needed among clinicians and the general public, as patients with knowledge of coccidioidomycosis may be more likely to be diagnosed earlier than those unfamiliar with the disease,” the authors wrote.

SOURCE:

This study was led by Samantha L. Williams, MPH, National Center for Emerging and Zoonotic Infectious Diseases, CDC, Atlanta. It was published online on June 3, 2025, in JAMA Network Open.

LIMITATIONS:

The NNDSS data, used as the primary model input, captured only cases from states where coccidioidomycosis was reportable, requiring approximations for nonreporting states. Several multiplier values relied on expert opinion and lacked validation due to limited data. This study also did not account for demographic, medical, or exposure-related risk factors or lifelong immunity. 

DISCLOSURES:

This study did not receive any specific funding. Few authors reported receiving funds from the CDC. Additionally, three authors reported receiving financial aid from certain pharmaceutical organizations.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.