The mysterious desert dwellers:Coccidioides immitis and Coccidioides posadasii, causative fungal agents of coccidioidomycosis

Abstract

The genus Coccidioides consists of two species: C. immitis and C. posadasii . Prior to 2000, all disease was thought to be caused by a single species, C. immitis . The organism grows in arid to semiarid alkaline soils throughout western North America and into Central and South America. Regions in the United States, with highest prevalence of disease, include California, Arizona, and Texas. The Mexican states of Baja California, Coahuila, Sonora, and Neuvo Leon currently have the highest skin test positive results. Central America contains isolated endemic areas in Guatemala and Honduras. South America has isolated regions of high endemicity including areas of Colombia, Venezuela, Argentina, Paraguay, and Brazil. Although approximately 15,000 cases per year are reported in the United States, actual disease burden is estimated to be in the hundreds of thousands, as only California and Arizona have dedicated public health outreach, and report and track disease reliably. In this review, we survey genomics, epidemiology, ecology, and summarize aspects of disease, diagnosis, prevention, and treatment.

Primary cutaneous coccidioidomycosis in an immunocompetent oil field worker in West Texas

“…Observed increases in incidence may be attributable to improved reporting, better diagnostic tools, changing climate, increased construction and soil disturbance, and population growth. [3] Those at greater risk for exposure include people involved in construction work, farm work, archeological digs, and also prison inmates and guards. [3] In addition, populations known to have greater risk for severe disease include African Americans, Filipinos, pregnant women, and immunosuppressed individuals, such as those with HIV/AIDS, hematologic malignancies, inflammatory arthritides, diabetes mellitus, as well as those with solid organ transplantation and subsequent use of immunosuppressive agents.…”

“…[3] Those at greater risk for exposure include people involved in construction work, farm work, archeological digs, and also prison inmates and guards. [3] In addition, populations known to have greater risk for severe disease include African Americans, Filipinos, pregnant women, and immunosuppressed individuals, such as those with HIV/AIDS, hematologic malignancies, inflammatory arthritides, diabetes mellitus, as well as those with solid organ transplantation and subsequent use of immunosuppressive agents. [2] Our patient had a workrelated exposure in an underreported, likely endemic area, and was of a racial background (African American) known to carry increased risk for infection and spread.…”

“…[2] The disease was first described in the late 1800's in Argentina by Dr. Alejandro Posadas, but it wasn't until the 1930's when the broad clinical spectrum of coccidioidomycosis was appreciated. [3,4] The Coccidioides species are dimorphic, soil-dwelling fungi capable of causing systemic disease through inhalation of airborne arthroconidia from the soil. Primary pulmonary coccidioidomycosis is the most common site of infection, with an estimated 60% of cases being asymptomatic.…”

Proper Care and Feeding of Coccidioides: A Laboratorian's Guide to Cultivating the Dimorphic Stages of C. immitis and C. posadasii

“…Mycelia are the saprobic phase of Coccidioides and are useful for studying physiology related to the environmental phase of the lifecycle (Fisher, Koenig, et al, 2001;Kollath, Miller, & Barker, 2019). These fungi are often associated with rodents/rodent burrows, armadillos, or archeological sites and are more likely to degrade animal proteins than those associated with plants (Baptista-Rosas, Catalán-Dibene, et al, 2012;Del Rocio Reyes-Montes et al, 2016;Emmons, 1942;Kollath, Teixeira, Funke, Miller, & Barker, 2020;Sharpton et al, 2009).…”

Strong population structure in Venezuelan populations ofCoccidioides posadasii

“…Coccidioidomycosis or “Valley Fever” is an example of one of these primary fungal diseases, and is caused by the saprobic species Coccidioides immitis and C. posadasii (17). The disease range overlaps arid regions throughout the American continent, but California and Arizona encompass the vast majority of reported cases of the disease (18).…”