TB hard to trace and testing is only 80 percent accurate
May 4, 2018
LOVELAND, Colo. — According to the U.S. Department of Agriculture's Animal and Plant Health Inspection Service, bovine Tuberculosis is "nearly eliminated from the livestock population of the United States," but one of the biggest obstacles is the lack of traceability when it comes to fully eliminating bovine TB.
Speaking at the dairy meeting during the annual Colorado Livestock Association meeting, Keith Roehr, Colorado state veterinarian, discussed the problems facing Bovine TB testing and tracking.
One of the biggest obstacles concerning bovine TB is the lack of accurate testing. Roehr said the test, "at best" is accurate only 80 percent of the time.
"That's just the reality of what we have," he said.
Colorado has regulations in place that requires TB testing of livestock crossing into the state, but without reliable testing infected animals can still get into the state.
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Unfortunately, it's a problem missing those infected because it could lead to more livestock and eventually humans to become infected the longer it goes undetected.
The last detection in Colorado was on a dairy about eight years ago and wasn't found until the cow was on slaughter surveillance.
Roehr said there are cows that slip through the system, though.
Bovine TB passes through the air, primarily, so with problems with the accuracy of the test, knowing where strains originated from can be an important.
It's hard to trace where some livestock got TB in the first place, especially when the strains are hard to pinpoint.
"It's incredibly frustrating because it's usually a new strain," Roehr said.
But most likely the strain came from Mexico, but with a number of new strains and a test that misses a lot of cases, it's really too tough to tell. Plus it's hard to really catch the trail that leads to certain TB cases.
It's an issue Colorado producers should keep in mind, Roehr said, because of its close proximity to Mexico. But it's also important to know who raises the heifers and what feedlots they're in. That can be an important indicator in a pretty unpredictable situation.
"Most of the dairies that get TB, usually, didn't do anything wrong," Roehr said.
He emphasized the problem in Mexico, due to less stringent regulations as the U.S. has in regards to TB testing and milk processing.
There are high levels of TB in parts of Mexico, Roehr said.
"I tell people: If you go to Mexico, drink the water not the milk. The milk can give you TB unless it's pasteurized."
But, overall, the largest problem comes from a lack of better technology when it comes to TB. With tests only about 80 percent accurate, on the optimistic end, and the dead ends that tracing strains lead to, it's hard to completely eliminate TB at this time.
"The skin test we have is the same we had before," Roehr said. "Still looking for the needle in the haystack." ❖
— Fox is a reporter for The Fence Post. She can be reached at (970) 392-4410, firstname.lastname@example.org or on Twitter @FoxonaFarm.