Coccidioidomycosis-associated Hospitalizations, California, USA, 2000–2011

Gail Sondermeyer

, Lauren Lee, Debra Gilliss, Farzaneh Tabnak, and Duc Vugia

Author affiliations: California Department of Public Health, Richmond, CA, USA

Abstract

In the past decade, state-specific increases in the number of reported cases of coccidioidomycosis have been observed in areas of California and Arizona where the disease is endemic. Although most coccidioidomycosis is asymptomatic or mild, infection can lead to severe pulmonary or disseminated disease requiring hospitalization and costly disease management. To determine the epidemiology of cases and toll of coccidioidomycosis-associated hospitalizations in California, we reviewed hospital discharge data for 2000–2011. During this period, there were 25,217 coccidioidomycosis-associated hospitalizations for 15,747 patients and >$2 billion US in total hospital charges. Annual initial hospitalization rates increased from 2.3 initial hospitalizations/100,000 population in 2000 to 5.0 initial hospitalizations/100,000 population in 2011. During this period, initial hospitalization rates were higher for men than women, African Americans and Hispanics than Whites, and older persons than younger persons. In California, the increasing health- and cost-related effects of coccidioidomycosis-associated hospitalizations are a major public health challenge.

Coccidioidomycosis, also known as Valley fever, is a reemerging infectious disease caused by inhalation of Coccidioides fungi spores, which reside in the soil of regions where coccidioidomycosis is endemic, including the southwestern United States (1–5). California and Arizona have the highest rates of reported coccidioidomycosis cases in the United States (4,6). In California, the pathogen is most common in the San Joaquin Valley, and compared with other Californians, residents of this region are at increased risk for infection (6,7). Although most coccidioidomycosis cases are asymptomatic, symptomatic disease will develop in ≈40% of patients and can range from self-limited influenza-like illness to disseminated disease and chronic meningitis (7,8). Symptomatic disease can require expensive and aggressive treatments, prolonged absence from work or school, multiple hospitalizations, and years of monitoring (9,10). Populations at particular risk for severe disease include African Americans, immunocompromised persons, and persons > 65 years of age (2,11).
Over the past decade, increases in the number of reported cases of coccidioidomycosis have been documented from Arizona and California (6,12–16). In California, the rates of reported cases increased > 6-fold from 2000 to 2011 (2.4 to 14.4 cases/100,000 population, respectively) (13,15). Cases among prisoners in California also increased during this time, making prisoners a population of concern (17,18). To determine the epidemiology, extent, and effect of the disease in California, we reviewed coccidioidomycosis-associated hospitalizations in the state for 2000–2011.