Equine Infectious Anemia
Equine Infectious Anemia (EIA or swamp fever) is a viral disease spread by horseflies, for which there is no vaccine and no cure. For some horses there may be a period of general illness. As a result, EIA detection may not appear for over a month. Asymptomatic carriers can appear healthy.
Many states have stringent EIA testing requirements before horses can be transported across their borders. For example Kentucky requires proof of a negative USDA-approved EIA test within the past several months, and still reserves the right to quarantine horses upon entry.
The AGID, more commonly known as the Coggins test, is the international standard for the detection of antibodies to the EIA by measuring antibodies to the genetically stable (p26) core protein of the virus. It has been proven to be very reliable and is therefore the primary method to certify horses free of EIA for exportation, transportation, and show purposes. The test is simple to perform, but is subject to interpretation results, which are not available for 24-48 hours.
Limitations of the Coggins test include:
- Possible false negative results with very low antibody levels
- Possible false positive results when EIA-negative foals are born to EIA-positive mares when the foals receive colostral antibodies against the EIA virus
- Weak sensitivity to newly infected animals; animals usually only test positive by 15-25 days post infection.
To overcome these limitations, AAD is developing an on-site test that will perform a simultaneous measurement of both the (p26) antibody response and the activated lymphocyte reactivity upon re-exposure to the core (p26) antigen.
This simultaneous detection has become feasible through a novel application of the AAD patent portfolio. The AAD UDP™ solution will be performed on-site and will be available in hours, whereas the AGID answer must be done in a remote laboratory and will not be available for 24-48 hours. The UDP™ is also more sensitive to newly infected animals than the AGID test.
Broader Impact
The application of this technology extends to other diseases where the antibody response may be not immediate. Well known examples of this condition are Jones Disease, Bovine Tuberculosis and Lyme disease.