Coccidioides immitis infection

Clemons KV, Leathers CR, Lee KW. Systemic Coccidioides immitis infection in nude and beige mice. Infect Immun 1985 47 814-821. 

Magee DM, Cox RA. Interleukin-12 regulation of host defenses against Coccidioides immitis. Infect Immun 1996 64(9) 3609-3613. 

Coccidioidomycosis is caused by infection with Coccidioides immitis. The endemic regions encompass the semi-arid regions of the southwestern United States from California to Texas, known as the Lower Sonoran Zone. It encompasses a spectrum of illnesses ranging from primary uncomplicated respiratory tract infection that resolves spontaneously to progressive pulmonary or disseminated infection. 

Coccidioides immitis is a dimorphic fungus that grows in soil in much of the southwestern United States infection results from inhalation of airborne C. immitis arthroconidia. Coccidioidomycosis is not transmitted from person to person. Approximately 60% of infected persons are asymptomatic the remainder can develop a spectrum of disease from mild influenza-like illness to pneumonia to disseminated disease, including meningitis. Because the incubation period for this infection ranges from 1 to 4 weeks, persons who may... 

Chrysosporium zonatum was detected recently as the agent of a disseminated infection in a patient with chronic granulomatous disease. C. zonatum is the anamorph of the heterothallic ascomycete Uncinocarpus orissi [276]. Although a dimorphism is absent, this species is phylogenetically closely related to Coccidioides immitis [277]. It produces abundant arthroconidia and degrades cellulose as well as keratin [277]. 

For systemic treatment of fungal infections in dogs and cats, ketoconazole and fluconazole are available as tablets and oral suspensions, itraconazole as capsules, while miconazole and fluconazole are available as parenteral solutions. Even though ketoconazole is often effective, itraconazole may be the preferred azole for the treatment of systemic disease caused by dimorphic fungi (Blastomyces dermatitidis, Histoplasma capsulatum, Sporothrix schenckii). The activity of fluconazole against dimorphic fungi is limited to coccidioidal disease (Coccidioides immitis), but this azole penetrates the blood-brain barrier. 

Individuals in certain occupations are more frequently exposed to the contaminated soil (dust) and therefore are more likely to be infected with Coccidioides immitis. Among them agricultural and construction workers or military personnel, geologists, archaeologists, etc. are most frequently affected. It is well known that the fungus poses a health hazard to hospital and medical laboratory workers even outside the endemic regions (Johnson 1981). 

This helps to understand the transmission of certain diseases by air. Valley Fever, for example, is a sometimes very serious disease caused by the fungal agent Coccidioides immitis (Cl). Infection starts with the inhaling of airborne particles, most of these averaging less than 10 microns in diameter. Over 80 percent of people in certain endemic areas of the western United States test positive for having been exposed to CI,25 a clear demonstration of how infectious particles can spread by aerosol. 

Coccidioidomycosis is caused by infection with Coccidioides immi-tis, a dimorphic fungus found in the southwestern and western United States, as well as in parts of Mexico and South America. In North America, the endemic regions encompass the semiarid areas of the southwestern United States from California to Texas known as the Lower Sonoran Zone, where there is scant annual rainfall, hot summers, and sandy, alkaline soil. C. immitis grows in the soil as a mold, and mycelia proliferate during the rainy season. During the dry season, resistant arthroconidia form and become airborne when the soil is disturbed. 

With chronic, persistent pneumonia, C. immitis often can be cultured from the sputum for a period of several years. Chest radiographs usually demonstrate apical fibronodular lesions or slowly progressive cavitation. With CNS infection, analysis of the CSF generally reveals a lymphocytic pleocytosis with elevated protein and a decreased glucose concentration. Although serum usually is positive for coccidioidal CF antibodies, the coccidioidal skin test is often negative. 

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