equine assay data sheet

Histoplasma

Test code: F0006 - Ultrasensitive qualitative detection of Histoplasma species by real time polymerase chain reaction

Histoplasma is a genus of dimorphic fungi belonging to the family Ajellomycetaceae which are commonly found in bird and bat fecal material. The Histoplasma genus includes H. capsulatum which causes histoplasmosis; H. farciminosum which causes epizootic lymphangitis in horses; and H. duboisii which causes African histoplasmosis.

H. capsulatum is most prevalent in the Ohio and Mississippi river valleys. The disease caused by H. capsulatum is called histoplasmosis, also known as "cave disease," "Darling's disease," "Ohio Valley disease," "Reticuloendotheliosis," "spelunker’s lung" and “caver's disease.” Symptoms primarily affect the lungs, but other organs can be affected if the fungus spreads in the body. Histoplasmosis is commonly found in immunocompromised individuals such as AIDS patients and cancer patients.

People can be infected by inhaling microscopic fungi borne from bird or bat feces, or decomposing human biological fluids including urine, vomit, and feces.

Histoplasmosis can be diagnosed by detection of antigens in blood or urine samples by immunological or molecular methods. However, immunology is not very specific because antigens of Histoplasma can cross-react with antigens of blastomycosis, coccidioidomycosis, paracoccidioidomycosis and Penicillium marneffei infection. Formal histoplasmosis diagnoses may be confirmed by culturing the fungus directly. However, cultures may take up to 6 weeks for diagnostic growth to occur. Molecular detection by polymerase chain reaction (PCR) can provide a rapid, specific and sensitive method for diagnosis of this fungus (Elias et al., 2012).

Utilities:

• Help confirm the disease causing agent
• Shorten the time required to confirm a clinical diagnosis of Histoplasma infection.
• Help ensure that herds are free of this fungus
• Early prevention of spread of this fungus
• Minimize personnel exposure to this fungus
• Safety monitoring of biological products and vaccines that derive from horses

References:
Elías, N.A., Cuestas, M.L., Sandoval, M., Poblete, G., Lopez-Daneri, G., Jewtuchowicz, V., Iovannitti, C. and Mujica, M.T. (2012) Rapid identification of Histoplasma capsulatum directly from cultures by multiplex PCR. Mycopathologia. 174:451-456.

Specimen requirements: 0.2 ml bird or bat feces, or 0.2 ml whole blood in EDTA (purple top) tube, or urine, or sputum, or bronchoalveolar lavage, or fecal swab, or 0.2 ml fresh, frozen or fixed tissue, or environmental surface swab.

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