Coccidioidomycosis (, kok-SID-ee-oy-doh-my-KOH-sis), 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. Coccidioidomycosis is endemic in certain parts of the United States in Arizona, California, Nevada, New Mexico, Texas, Utah, and northern Mexico.C. immitis is a dimorphic saprophytic fungus that grows as a mycelium in the soil and produces a spherule form in the host organism. It resides in the soil in certain parts of the southwestern United States, most notably in California and Arizona. It is also commonly found in northern Mexico, and parts of Central and South America. C. immitis is dormant during long dry spells, then develops as a mold with long filaments that break off into airborne spores when it rains. The spores, known as arthroconidia, are swept into the air by disruption of the soil, such as during construction, farming, low-wind or singular dust events, or an earthquake. Windstorms may also cause epidemics far from endemic areas. In December 1977, a windstorm in an endemic area around Arvin, California led to several hundred cases, including deaths, in non-endemic areas hundreds of miles away.Coccidioidomycosis is a common cause of community-acquired pneumonia in the endemic areas of the United States. Infections usually occur due to inhalation of the arthroconidial spores after soil disruption. The disease is not contagious. In some cases the infection may recur or become chronic.
In retrospect, Smith played a major role in both medical research and raising awareness about coccidioidomycosis, especially when he became dean of the School of Public Health at the University of California at Berkeley in 1951. Coccidioides immitis was considered by the United States during the 1950s and 1960s as a potential biological weapon. The strain selected for investigation was designated with the military symbol OC, and initial expectations were for its deployment as a human incapacitant. Medical research suggested that OC might have had some lethal effects on the populace, and Coccidioides immitis started to be classified by the authorities as a threat to public health. However, Coccidioides immitis was never weaponized to the publics knowledge, and most of the military research in the mid-1960s was concentrated on developing a human vaccine. Currently, it is not on the U.S. Department of Health and Human Services or Centers for Disease Control and Preventions list of select agents and toxins. In 2002, Coccidioides posadasii was identified as genetically distinct from Coccidioides immitis despite their morphologic similarities and can also cause coccidioidomycosis. Research
As of 2013, there is no vaccine available to prevent infection with  Coccidioides immitis or Coccidioides posadasii, but efforts to develop such a vaccine are underway. Other animals
Valley fever is not contagious. In dogs, the most common symptom of coccidioidomycosis is a chronic cough, which can be dry or moist. Other symptoms include fever (in approximately 50% of cases), weight loss, anorexia, lethargy, and depression.