''Coccidioides'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

of dimorphic ascomycetes in the family

Onygenaceae The Onygenaceae are a family of fungi in the Ascomycota, class Eurotiomycetes. Genera These are the genera that are in the Onygenaceae, according to a 2021 review of fungal classification. Following the genus name is the taxonomic authority (t ...

. Member species are the cause of

coccidioidomycosis Coccidioidomycosis (, ), commonly known as cocci, Valley fever, as well as California fever, desert rheumatism, or San Joaquin Valley fever, is a mammalian fungal disease caused by '' Coccidioides immitis'' or ''Coccidioides posadasii''. Coccid ...

, also known as San Joaquin

Valley fever A valley is an elongated low area often running between hills or mountains, which will typically contain a river or stream running from one end to the other. Most valleys are formed by erosion of the land surface by rivers or streams ove ...

, an infectious fungal disease largely confined to the

Western Hemisphere The Western Hemisphere is the half of the planet Earth that lies west of the prime meridian (which crosses Greenwich, London, United Kingdom) and east of the antimeridian. The other half is called the Eastern Hemisphere. Politically, the te ...

and endemic in the Southwestern United States. The

host A host is a person responsible for guests at an event or for providing hospitality during it. Host may also refer to: Places * Host, Pennsylvania, a village in Berks County People *Jim Host (born 1937), American businessman * Michel Host ...

acquires the disease by respiratory inhalation of spores disseminated in their natural habitat. The causative agents of coccidioidomycosis are ''

Coccidioides immitis ''Coccidioides immitis'' is a pathogenic fungus that resides in the soil in certain parts of the southwestern United States, northern Mexico, and a few other areas in the Western Hemisphere. Epidemiology ''C. immitis'', along with its relati ...

'' and ''

Coccidioides posadasii ''Coccidioides posadasii'' is a pathogenic fungus that, along with ''Coccidioides immitis'', is the causative agent of coccidioidomycosis, or valley fever in humans. It resides in the soil in certain parts of the Southwestern United States, no ...

''. Both ''C. immitis'' and ''C. posadasii'' are indistinguishable during laboratory testing and commonly referred in literature as ''Coccidioides''.

Clinical presentation

Coccidioidomycosis is amazingly diverse in terms of its scope of clinical presentation, as well as clinical severity. About 60% of ''Coccidioides'' infections as determined by serologic conversion are asymptomatic. The most common clinical syndrome in the other 40% of infected patients is an acute respiratory illness characterized by fever, cough, and

pleuritic Pleurisy, also known as pleuritis, is inflammation of the membranes that surround the lungs and line the chest cavity (pleurae). This can result in a sharp chest pain while breathing. Occasionally the pain may be a constant dull ache. Other sym ...

pain. Skin manifestations, such as

erythema nodosum Erythema nodosum (EN) is an inflammatory condition characterized by inflammation of the fat cells under the skin, resulting in tender red nodules or lumps that are usually seen on both shins. It can be caused by a variety of conditions, and typi ...

, are also common with ''Coccidioides'' infection. ''Coccidioides'' infection can cause a severe and difficult-to-treat meningitis in AIDS and other immunocompromised patients, and occasionally in immunocompetent hosts. Infection can sometimes cause acute respiratory distress syndrome and fatal multilobar pneumonia. The risk of symptomatic infection increases with age.

Epidemiology

The primary coccidioidomycosis-

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found else ...

areas are located in Southern California and southern Arizona, and northern Mexico, in Sonora, Nuevo León, Coahuila, and Baja California, where it resides in soil. Both ''C. immitis'' and ''C. posadasii'' were viewed as desert saprophytes, but recent genomic research revealed ''Coccidioides'' species to have evolved interacting with their animal hosts.

Etymology

The soil fungus ''Coccidioides'' was discovered in 1892 by Alejandro Posadas, a medical student, in an

Argentinian Argentines (mistakenly translated Argentineans in the past; in Spanish ( masculine) or ( feminine)) are people identified with the country of Argentina. This connection may be residential, legal, historical or cultural. For most Argentines, ...

soldier with widespread disease. Biopsy specimens revealed organisms that resembled the protozoan

Coccidia Coccidia (Coccidiasina) are a subclass of microscopic, spore-forming, single-celled obligate intracellular parasites belonging to the apicomplexan class Conoidasida. As obligate intracellular parasites, they must live and reproduce within an ...

(from the Greek kokkis, "little berry"). In 1896, Gilchrist and Rixford named the organism ''Coccidioides'' ("resembling Coccidia") ''immitis'' (Latin for “harsh,” describing the clinical course). Ophüls and Moffitt proved that ''C. immitis'' was a fungus rather than a protozoan in 1900. In 2002, ''C. immitis'' was divided into a second species, '' C. posadasii'', after

Alejandro Posadas Alejandro Posadas (December 28, 1870 – November 21, 1902) was an Argentinian physician and surgeon specializing in pediatric surgery. He was the first person to film an operation and brought the first x-ray to the country of Argentina. Posadas ...

. .

References

''This article cites public domain text from the CDC, as shown.''

External links

''Coccidioides'' sp.National Center for Biotechnology Information: Coccidioides
{{Taxonbar, from=Q142764 Eurotiomycetes genera Onygenales Taxa described in 1896