Symptomatic persons (40% of cases) usually present 1 to 3 weeks after exposure with fatigue, cough, dyspnea, headache, night sweats, myalgias, and rash.1-3 Primary pulmonary disease is often self-limiting, but some patients fail to recover and develop complications or chronic pulmonary disease (approximately 5 to 10% of cases). Disseminated disease occurs in an estimated 1% of cases (higher rates of dissemination are observed in certain risk groups), with bones/joints, soft tissues, and meninges most commonly affected.
Coccidioides immitis (typically in California) and Coccidioides posadasii (typically outside of California).4 Clinical differences between the two species have not been observed.
Reservoir and endemic areas
Soil in the southwestern United States, parts of Mexico, and South America. Highly endemic areas include southern Arizona and California’s southern San Joaquin Valley.
Coccidioidomycosis is typically acquired via inhalation of airborne arthroconidia, often after disturbance of contaminated soil (e.g., small-scale activities including construction or excavation, or large-scale events such as dust storms and earthquakes). Primary cutaneous coccidioidomycosis,5 solid organ donor-derived coccidioidomycosis,6 and fomite-transmitted coccidioidomycosis 7-8 can also occur but are very uncommon.
In persons who develop progressive, chronic, or disseminated disease, symptoms may persist for months or even longer. Meningitis can lead to permanent neurologic damage. Mortality is high in HIV-infected persons with diffuse lung disease.
Serologic tests to detect IgM and IgG antibodies are most often used to diagnose coccidioidomycosis.9 Other methods include culture and microscopy.
- Enzyme immunoassay (EIA): A very sensitive and commonly used method for diagnosing coccidioidomycosis. Two Coccidioides EIAs are currently available:
- Premier ® Coccidioides EIA – Meridian Bioscience, Inc.
- Coccidioides Antibody Enzyme Immunoassay – Immuno Mycologics, Inc. (IMMY)
- Immunodiffusion (ID): detects IgM antibodies; positive early in the course of infection.
- Complement Fixation (CF): detects IgG antibodies and allows for assessment of disease severity.
- Culture: Can be performed on tissue and respiratory specimens; however, sputum can be difficult to obtain for culture since patients’ coughs are often non-productive.
- Microscopy: for detection of spherules in tissue or respiratory secretions; low sensitivity.
- Urinary antigen detection: Not widely used, but may have some utility in diagnosing coccidioidomycosis in immunocompromised patients with severe forms of the disease.10
- Polymerase Chain Reaction (PCR): PCR for detection of Coccidioides directly from clinical specimens is still experimental, but promising.11,12
Laboratory culture of Coccidioides immitis
Lung tissue with Coccidioides spherule
The optimal management for patients with uncomplicated primary pulmonary coccidioidomycosis is unclear. Some infections will resolve without antifungal treatment, but some physicians choose to treat all symptomatic patients. Infectious Disease Society of America (IDSA) guidelines suggest treatment for primary pulmonary coccidioidomycosis in patients who:
- Are immunosuppressed (due to HIV/AIDS, receipt of an organ transplant, or receipt of high-dose corticosteroids or TNF-inhibitors)
- Have diabetes mellitus or underlying cardiopulmonary disease
- Are pregnant
- Are black or Filipino
- Have severe illness
Oral azoles are a popular first-line therapy. Although ketoconazole is the only one that has been approved by the FDA for use in coccidioidomycosis, most experts prefer either fluconazole or itraconazole. Some studies have indicated that azoles should be used at a minimum dose of 400mg daily and that relapses are frequent after discontinuation of therapy.13-14 Fluconazole has shown to be the most effective for treating coccidioidal meningitis.15 For the management of severely ill patients or pregnant women, some clinicians still turn to intravenous amphotericin B. However, amphotericin B intravenously is ineffective for coccidioidal meningitis and must be administered intrathecally. For detailed treatment guidelines, please refer to the Infectious Disease Society of America’s Practice Guidelines for the Treatment of Coccidioidomycosis
People in endemic areas, particularly those who have occupations or participate in activities exposing them to dust (e.g., construction or agricultural workers, archaeologists, and military trainees). Risk factors for severe or disseminated coccidioidomycosis include African-American race16 or Filipino ethnicity,17 HIV/AIDS,18 use of immunosuppressive medications,19 organ transplant,20 diabetes mellitus,16 or pregnancy.21
Surveillance and statistics
Coccidioidomycosis is nationally notifiable and is reportable in the following states: Arizona, California, Delaware, Louisiana, Maryland, Michigan, Minnesota, Missouri, Montana, Nebraska, Nevada, New Hampshire, New Mexico, North Dakota, Ohio, Rhode Island, Utah, Washington, and Wyoming. Check with your local, state, or territorial public health department for more information about disease reporting requirements and procedures in your area. Click here for coccidioidomycosis statistics.
Areas for further research
- Determining the optimal treatment regimen for primary pulmonary coccidioidomycosis
- Identifying host factors associated with increased risk for dissemination in select racial/ethnic groups to target prevention efforts
- Understanding the factors associated with increasing incidence in endemic areas
- Determining the influence of climate change on Coccidioides’ geographic distribution
- Developing improved methods for detection of Coccidioides in environmental samples
- Creating an effective vaccine