Battle to Eradicate Bovine TB
Testing in 2004 on white-tailed deer shows that much progress toward eradication of bovine TB in the wildlife population has been made, according to a Michigan Department of Natural Resources study.
In 15,127 white-tailed deer tested in 2004, 28 animals turned up bovine TB-positive. In Deer Management Unit (DMU) 452 in northeastern Lower Michigan, the hardest hit area for bovine TB, the prevalence for the disease was 1.7 percent, according to the study, which was a decrease of 65 percent since 1995, when the disease was first detected in that area.
"While it is too early to claim a victory against bovine TB, we are very encouraged by the 2004 test results," said Stephen Schmitt, wildlife veterinarian-in-charge at the DNR's Wildlife Disease Laboratory. "Our intervention strategies are working, and we need to stay the course. We also are looking for new intervention methods that will help us further reduce the disease rate in deer. These strategies also should be more acceptable to hunters and landowners."
Currently, the strategies for eradication of the disease have centered on reducing the deer population densities through hunting and reducing deer congregation by restricting or eliminating bait and feed. New strategies, though not intended to replace the existing strategies, would involve live-trapping and TB testing of wild deer and the removal of infected animals.
In 2004, the DNR also worked on developing a more accurate blood test for bovine TB. The pilot program involved hunters in DMU 452 who collected blood samples from deer harvested in the area. The hunters submitted the blood sample and deer head to a deer check station. The lymph nodes from the deer head were cultured for TB, and the results were compared to four different TB tests on the blood. One TB test appeared promising, Schmitt said, and could be performed in the field with results ready in less than 15 minutes.
In 2005, the DNR will continue TB surveillance in DMU 452 and northeastern Michigan and focus on a collaborative effort with federal and private scientists to develop an accurate TB blood test and an effective TB vaccine.
"Clearly, we are winning important battles in the war on bovine TB," Schmitt said. "Eradication of this disease from the white-tailed deer herd is important to economic vitality of northeastern Michigan, and our research and management of this disease is crucial to that effort."
For more information on the study, please visit the bovine tuberculosis section of Michigan's Emerging Diseases Web site.