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

Daniel R Kollath,Karis J Miller,Bridget M Barker

doi:10.1080/21505594.2019.1589363

Abstract

ABSTRACTThe 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.

Highlights

The disease coccidioidomycosis, which is commonly known as valley fever (VF), was first described in the late 1800s in Argentina by Dr Alejandro Posadas [1]
This environmental life stage consists of nondescript mycelia that mature into alternating arthroconidia as the fungus grows and ages
The genus Coccidioides consists of two species: C. immitis and C. posadasii

Summary

Introduction

The disease coccidioidomycosis, which is commonly known as valley fever (VF), was first described in the late 1800s in Argentina by Dr Alejandro Posadas [1]. Most ascomycete fungi are saprotrophic in the environment and have an association with plants, but Coccidioides spp. has evolved the ability to infect immunocompetent mammals including humans [21]. The distribution of the fungus in soil is inconsistent and unpredictable even in the endemic region where there is high disease burden [22].

Results

Conclusion