Northern Michigan at High Risk for Bovine Tuberculosis

The Michigan Department of Agriculture and Rural Development has established 2 "Potential High Risk Areas" for the disease after the Michigan Department of Natural Resources found a white-tailed deer tested positive for bovine TB in Presque Isle County. Another deer was also found with the disease in northwestern Montmorency County.

The designation requires all nearby cattle and bison herds be tested for bovine TB within the next 6 months. The cattle and bison on farms within a 10-mile [16-km] radius of either deer found with TB will have to be tested for the disease. According to the Department of Agriculture, some cattle farms are already tested for TB on an annual basis. No additional TB testing will be needed on those farms.

All impacted cattle owners will be contacted and asked to schedule a test to avoid the possibility of quarantine being placed on their farms.

A meeting will also be held on [8 Apr 2014] to discuss the TB Program and the regions designated as Potential High Risk Areas. It will take place at the Presque Isle District Library in Rogers City at 7 pm.

Bovine tuberculosis has one of the widest host ranges of all the tuberculosis complex and can readily spill over into a variety of domestic and wild mammals, including humans. This makes control by culling very frustrating and inefficient.

In North America, naturally occurring tuberculosis has been reported in white-tailed deer, elk, and mule deer. Surveillance efforts like the one that detected these cases of bovine TB in deer are key to provide an early warning of risk of transmission to livestock and also to produce crucial data to better understand the eco epidemiology of the disease.

Bovine TB is usually transmitted to humans by infected milk, although it can also spread via aerosol droplets. Actual infections in humans are rare, mainly because pasteurisation kills any bacteria in infected milk; also, cattle are randomly tested for the disease and immediately culled if infected, but can still be used for human consumption. However, in areas of the developing world where pasteurisation is not routine, Bovine TB is a relatively common cause of human tuberculosis.

Bovine TB is a chronic infectious disease which affects a broad range of mammalian hosts, including humans, cattle, deer, llamas, pigs, domestic cats, foxes, coyotes, opossums, mustelids and rodents. It rarely affects equids or sheep The disease can be transmitted in several ways; for example, it can be spread in exhaled air, sputum, urine, faeces and pus, so the disease can be transmitted by direct contact with the excreta of an infected animal, or inhalation of aerosols, depending on the species involved.