Coccidioidomycosis / Valley Fever (Coccidioides spp.)
2011 Case Definition

Clinical Criteria

Infection may be asymptomatic or may produce an acute or chronic disease. Although the disease initially resembles an influenza-like or pneumonia-like febrile illness primarily involving the bronchopulmonary system, dissemination can occur to multiple organ systems. An illness is typically characterized by one or more of the following:

• Influenza-like signs and symptoms (e.g., fever, chest pain, cough, myalgia, arthralgia, and headache)
• Pneumonia or other pulmonary lesion, diagnosed by chest radiograph
• Erythema nodosum or erythema multiforme rash
• Involvement of bones, joints, or skin by dissemination
• Meningitis
• Involvement of viscera and lymph nodes

Laboratory Criteria for Diagnosis

A confirmed case must meet at least one of the following laboratory criteria for diagnosis:

• Cultural, histopathologic, or molecular evidence of presence of Coccidioides species, OR
• Positive serologic test for coccidioidal antibodies in serum, cerebrospinal fluid, or other body fluids by:
  • Detection of coccidioidal immunoglobulin M (IgM) by immunodiffusion, enzyme immunoassay (EIA), latex agglutination, or tube precipitin, OR
  • Detection of coccidioidal immunoglobulin G (IgG) by immunodiffusion, EIA, or complement fixation, OR
  • Coccidioidal skin-test conversion from negative to positive after onset of clinical signs and symptoms

Case Classification