Coccidioidomycosis – Update

June 1, 2013
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By Stan Deresinski, MD, FACP, FIDSA, Clinical Professor of Medicine, Stanford University, Hospital Epidemiologist, Sequoia Hospital, Redwood City, CA, Editor of Infectious Disease Alert.

In the last issue of Infectious Disease Alert, we summarized a recent report demonstrating the increasing risk of coccidioidomycosis, especially in California and Arizona. The comment ended by pointing out the large number of cases of this fungal infection that occurred during construction of Interstate 5 down the spine of the highly endemic central valley of California and warning about the construction of high speed rail along a similar path in the near future. Since that issue, the problem has been highlighted by reports of two additional events.

The Central Valley of California is nothing if not sun drenched (except during episodes of tule fog — dense ground fog that has been the cause of huge traffic accidents on Interstate 5). An outbreak of coccidioidomycosis involving 28 workers at solar power construction plants in San Luis Obispo county in central California is under investigation by county and state public health personnel, as well as by CalOSHA. The two plants are the California Valley Solar and Topaz Solar Farm, located on the Carrizo Plain in the eastern portion of the county bordering the Central Valley, a semi-arid grassland at a mean 700 m elevation with only 230 mm rain annually features typical of the Lower Sonoran Life Zone that is loved by Coccidioides.

The problem leading to the outbreak is, of course, the disruption of the soil with release of dust containing arthroconidia into the air and their subsequent inhalation. Another project, the Antelope Valley Solar Ranch was recently ordered to cease construction because of dust blowing from the construction site to the nearby California town of Lancaster.

But that’s not the only problem recently presented by this dimorphic fungus. Pappagianis, in 2007, reported that two state prisons, the Pleasant Valley State Prison (PVSP) near Coalinga and Avenal State Prison (ASP) near Avenal on the western side of the San Joaquin Valley, had been hit hard by coccidioidomycosis as early as 2005 - 2006.1 In 2005, serologic testing identified 150 new cases from PVSP as well as 30 from ASP. In 2007-2010, the average annual incidence rates at ASP and PVSP were 1156/100,000 and 374/100,000, respectively.2 These rates were 16-fold and 123-fold greater than in their respective counties (Kings and Fresno). The relative risk for death in males due to coccidioidomycosis in adult institutions was 9.7 (95% CI 6.2 to 15.1) when compared to adult males statewide.

These and additional data have now led J. Clark Kelso, a federal receiver monitoring health in California’s overburdened correctional system, to request assistance from the Centers for Disease Control and Prevention in the investigation of deaths caused by coccidioidomycosis in state inmates.3 More drastically, he has also ordered the transfer of about 40% of the more than 8,200 inmates from the two state prisons. Those ordered to be transferred include patients known to be at risk for severe outcomes of coccidoidal infection, including Filipinos, African-Americans, individuals with immunocompromising disease or illness, and those >55 years of age, and those with signicant other selected comorbidities.

The problem with coccidioidomycosis among prison inmates housed in an endemic area brings to mind an occurrence in relation to World War II, by the end of which there were more than 400,000 enemy prisoners of war held within the U.S.4 More than 10,000 were housed in a prison in Florence, Arizona, which is located midway between Phoenix and Tucson. Unfortunately, coccidioidomycosis became epidemic among the prisoners, including those who were sent there for the climate because they had tuberculosis — a significant proportion of whom also developed the fungal infection. Concerned that they would be accused of violating the Geneva Conventions, authorities transferred inmates to other sites — a harbinger of the solution to be imposed in California more than seven decades later.


1. Pappagianis D. Coccidioidomycosis in California State Correctional Institutions. Ann NY Acad Sci 2007; 1111:103-11.

2. Schneider JL, et al. Coccidioidomycosis cases and deaths – Calfornia prison healthcare services, 2005-2010. Proceedings of the 55th Coccidioidomycosis Study Group Meeting, 2011.

3. Chris Clarke. Uh oh. Valley fever outbreak linked to solar development.

4. Deresinski, SC. The history of coccidioidomycosis. In, “Coccidioidomycosis”. Stevens, DA, Ed., Plenum, NY, 1-20, 1980.