C. immitis and C. posadasii cannot be distinguished on cytology or by symptoms, but only by DNA PCR.An indirect demonstration of fungal infection can be achieved also by serologic analysis detecting fungal antigen or host IgM or IgG antibody produced against the fungus. The available tests include the tube-precipitin (TP) assays, complement fixation assays, and enzyme immunoassays. TP antibody is not found in cerebrospinal fluid (CSF). TP antibody is specific and is used as a confirmatory test, whereas ELISA is sensitive and thus used for initial testing.If the meninges are affected, CSF will show abnormally low glucose levels, an increased level of protein, and lymphocytic pleocytosis. Rarely, CSF eosinophilia is present. Imaging
Chest X-rays rarely demonstrate nodules or cavities in the lungs, but these images commonly demonstrate lung opacification, pleural effusions, or enlargement of lymph nodes associated with the lungs. Computed tomography scans of the chest are more sensitive than chest X-rays to detect these changes. Prevention
Preventing Valley fever is challenging because it is difficult to avoid breathing in the fungus should it be present; however, the public health effect of the disease is essential to understand in areas where the fungus is endemic. Enhancing surveillance of coccidioidomycosis is key to preparedness in the medical field in addition to improving diagnostics for early infections. Currently there are no completely effective preventive measures available for people who live or travel through Valley fever-endemic areas. Recommended preventive measures include avoiding airborne dust or dirt, but this does not guarantee protection against infection.
In harmony with the mycelium life cycle, incidence increases with periods of dryness after a rainy season; this phenomenon, termed "grow and blow", refers to growth of the fungus in wet weather, producing spores which are spread by the wind during succeeding dry weather. While the majority of cases are observed in the endemic region, cases reported outside the area are generally visitors, who contact the infection and return to their native areas before becoming symptomatic. North America
In the United States, C. immitis is endemic to southern and central California with the highest presence in the San Joaquin Valley. C. posadassi is most prevalent in Arizona, although it can be found in a wider region spanning from Utah, New Mexico, Texas, and Nevada. An estimated 150,000 infections occur annually, with 25,000 new infections occurring every year. The incidence of coccidioidomycosis in the United States in 2011 (42.6 per 100,000) was almost ten times higher than the incidence reported in 1998 (5.3 per 100,000). In area where it is most prevalent, the infection rate is 2-4%.Incidence varies widely across the west and southwest. In Arizona, for instance, in 2007, there were 3,450 cases in Maricopa County, which in 2007 had an estimated population of 3,880,181 for an incidence of approximately 1 in 1,125. In contrast, though southern New Mexico is considered an endemic region, there were 35 cases in the entire state in 2008 and 23 in 2007, in a region that had an estimated 2008 population of 1,984,356, for an incidence of approximately 1 in 56,695.