Epidemiology, characteristics and results of coccidioidomycosis
Summary and introduction
Based on a 1957 Geographic Seropositivity Survey by Coccidioides, 3 counties in southwest Utah, United States, were listed as endemic to coccidioidomycosis, but there has been a lack of information on the burden of disease in Utah since then. We report the results of a recent clinical and epidemiological study on coccidioidomycosis in Utah. To describe the clinical features, we identified all coccidioidomycosis cases in an integrated health system in the country in 2006–2015. For the epidemiological analysis, we used cases reported to the Utah Department of Health in 2009–2015. The average incidence was 1.83 cases / 100,000 population / year. Washington County in southwest Utah had the highest incidence at 17.2 cases / 100,000 people / year. In a generalized linear model with time as a fixed effect, the mean annual temperature, population, and new build were associated with regional variations in incidence. Using these variables in a spatiotemporal model, we estimated the adjusted regional variation by county to predict areas where Coccidioides infections could increase.
Coccidioidomycosis, also known as Valley fever, is caused by Coccidioides immitis and C. posadasii, endemic, environmental dimorphic fungi found in the soil of the southwestern United States, Mexico, and Central and South America. Clinical infections range from asymptomatic to various manifestations, including pneumonia, soft tissue and osteoarticular infections, meningitis, and disseminated disease. Based on findings from the groundbreaking 1957 seropositivity study which established the generally accepted geographic distribution of Coccidioides in the United States, 6 states have been classified as endemic to coccidioidomycosis (Arizona, California, Nevada, New Mexico, Texas, and Utah); California and Arizona had the highest seroprevalence. Based on this study, 3 counties in southwest Utah were considered endemic to coccidioidomycosis: Iron, Kane, and Washington. With the exception of reports of a widespread coccidioidomycosis outbreak in 2001 during an archaeological dig in Uintah County at the US Park Service’s Dinosaur National Monument,[5–7] There is little published data on this disease in Utah. However, recent data suggests that southwest Utah may be an area of increased disease burden. Here we report a description of the epidemiology of coccidioidomycosis in Utah and examine environmental and climatic factors that contribute to regional variations in statewide incidence using data from cases reported to the Utah Department of Health (UDOH) during the period 2009-2015 became. We also describe clinical features and outcomes using patient-level data from the Intermountain Healthcare System in 2006-2015.