First Rapid Test for Chronic Wasting Disease, Validated in Colorado, Approved for Nationwide Use

The first rapid test to detect chronic wasting disease in deer has been granted a license by the United States Department of Agriculture for use nationwide. The test was validated by Colorado State University’s Veterinary Diagnostic Laboratory in cooperation with other Colorado State agencies.

The Bio-Rad rapid test for chronic wasting disease, or CWD, is an efficient procedure for diagnosing large numbers of samples in a short period of time. It takes only five hours to complete compared to the five days necessary for the "gold standard" Immunohistochemistry test. Additionally, the rapid test permits two to three times more samples to be processed in a single day. The IHC assay was also first validated at Colorado State’s Veterinary Diagnostic Laboratory in Fort Collins, Colo.

Through a cooperative effort among the Veterinary Diagnostic Laboratory, the Colorado Division of Wildlife, Colorado Department of Agriculture and the Colorado Veterinary Medical Association, a testing system for CWD was established for the collection of hunter-killed samples.

In this system, Colorado hunters now may submit deer and elk carcasses to the Division of Wildlife at sample collection sites or to participating veterinarians from the Colorado Veterinary Medical Association. Tissue samples are extracted and sent to Colorado State

University for diagnosis using the rapid rest for detection of possible CWD infection. The Immunohistochemistry test is used to confirm positive test results. If the rapid test shows a negative result, the IHC test would not be required. Results are released through the Colorado Division of Wildlife website three to seven days after the samples are taken, depending on daily sample volume.

The rapid test (CWD Antigen Test Kit, ELISA), manufactured by Bio-Rad Laboratories, a U.S. company based in California, looks for the Chronic Wasting Disease antigen in brain and lymphoid tissues using the Enzyme Linked Immunosorbant Assay, or ELISA method. The ELISA test allows for the rapid screening and quantification of the presence of the CWD antigen in the sample.

The rapid test performed well in field validation trials performed on more than 7,000 samples, successfully identifying all positive animals. Moreover, the test showed that lymphoid tissues are the more accurate choice for diagnosis of the disease as opposed to brain tissues. These findings appear to be consistent with current research indicating that abnormal prions accumulate in the lymphoid tissue prior to entering brain tissue.

Bio-Rad Laboratories, Inc. is a multinational manufacturer and distributor of life science research products and clinical diagnostics. It is based in Hercules, California with a network of more than 30 wholly-owned subsidiary offices.