Scientists with the USDA’s Agricultural Research Service have created a new test for detecting bovine tuberculosis.

The new blood-based assay test can detect the disease in most species of mammals with a single blood sample. That’s an important breakthrough as animals will only have to be handled once. Currently, the only government-approved tuberculosis test is a skin test that causes a reaction which must be checked in 72 hours. That means animals are handled twice which increases the chance for injury and stress for the animals — especially wildlife species.

A patent application for the test has been submitted by the U.S. Department of Agriculture on behalf of the inventors, veterinarians Ray Waters and Mitch Palmer. They work in the Bacterial Diseases of Livestock Research Unit at ARS' National Animal Disease Center in Ames, Iowa.

The assay works by detecting nitrite — as an indication of nitric oxide production — in blood-sample cultures. Mammals produce nitric oxide as a natural response when fighting tuberculosis.

  According to Waters, the test is an inexpensive and easy process for diagnostic laboratories and regulatory agencies. It will likely be used on livestock species such as cattle, sheep and goats and on wildlife such as deer, bison and elk.

The new, still-unnamed test can detect all three types of tuberculosis — human, avian, and bovine —according to Palmer. He notes that another test, an interferon gamma assay already in use for livestock, is based upon the same blood-culture principle as their procedure. However, it can't be used on other species and can only be applied in conjunction with the skin test.

To learn more about this new test, check out the November issue of Agricultural Research magazine, on the World Wide Web at:

Agricultural Research Service