Coccidioides (Valley fever) PCR test for primates

Coccidioides species are dimorphic fungi. Coccidioides immitis is endemic to the San Joaquin valley of California; Coccidioides posadasii is found in desert regions of the southwestern United States including Arizona, Utah, New Mexico, and West Texas, and also in parts of Mexico, Argentina, Paraguay and Central America. There is very little difference in morphology or clinical presentation between the 2 species, and both can cause the disease coccidioidomycosis, also referred to as "Valley Fever."

Coccidioides fungi are commonly found in soil and dust in endemic areas (Johnson et al., 2014). Arthroconidida are the infectious form of the fungi. When the arthroconidida dissociate, they can be carried by the wind for many miles. Coccidioidomycosis cases increase when there are rainy summers followed by dry winters, and after earthquakes or after humans disturb the soil by plowing, construction or similar activities.

When the anrthroconidida are inhaled into the lungs, they transform into multinucleated spherical structures containing hundreds of endospores. Most individuals will only develop a mild or asymptomatic pulmonary infection which resolves without intervention. However, some individuals who are infected may develop an apparent community-acquired pneumonia which often has an associated rash and arthralgias. The incubation time for the infection is about 2 weeks after exposure. Often these pneumonias resolve and only a few will progress to chronic pulmonary disease which can present as nodular or cavitary disease. Even fewer cases will progress to systemic or central nervous system coccidioidomycosis, but these forms are quite serious and are associated with heightened morbidity and mortality.

While most healthy individuals will normally not develop significant symptoms after exposure to these fungi, some groups of individuals are at increased risk for progression to extrapulmonary or disseminated coccidioidomycosis. Immunosuppressed animals are particularly susceptible.

Molecular detection by polymerase chain reaction (PCR) is often the method of choice for detection and identification of Coccidioides species, not only because of its speed, sensitivity and specificity, but also because of its utility on a variety of specimen types (Gago et al., 2014). PCR can be used to detect these fungi in environmental samples such as dust, water or soil, as well as in various samples of biological origin.

Utilities:

Detect these fungi in surface dust, soil, water or other environmental sample types
Help confirm the presence of the disease causing agent in biological samples
Help ensure that primate facilities are free of this fungus
Minimize occupational exposure to these fungi
Shorten the time required to confirm a clinical diagnosis of the infection
Selection of appropriate treatment regimens

References:
Gago, S., Buitrago, M.J., Clemons, K.V., Cuenca-Estrella, M., Mirels, L.F. and Stevens, D.A. (2014) Development and validation of a quantitative real-time PCR assay for the early diagnosis of coccidioidomycosis. Diagn. Microbiol. Infect. Dis. 79:214-221.

Johnson, S.M., Carlson, E.L., Fisher, F.S. and Pappagianis, D. (2014) Demonstration of Coccidioides immitis and Coccidioides posadasii DNA in soil samples collected from Dinosaur National Monument, Utah. Med. Mycol. 52:610-617.

Specimen requirements: Surface dust swab or gauze pad, or 10 ml soil, or 10 ml water, or throat or nasal swab, or 0.2 ml cerebrospinal fluid, or 0.2 ml whole blood in EDTA (purple top tube), or 0.2 ml fresh, frozen or fixed tissue

Contact Zoologix if advice is needed to determine an appropriate specimen type for a specific diagnostic application. For specimen types not listed here, please contact Zoologix to confirm specimen acceptability and shipping instructions.

For all specimen types, if there will be a delay in shipping, or during very warm weather, refrigerate specimens until shipped and ship with a cold pack unless more stringent shipping requirements are specified. Frozen specimens should be shipped so as to remain frozen in transit. See shipping instructions for more information.

Turnaround time: 2 business days

Methodology: Qualitative real time PCR

Normal range: Nondetected