Where did the TB come from?
The source of infection has not been identified yet. This investigation into the disease’s origin has been on-going since May 2009, when it was confirmed in a farmed cervid herd in Franklin County, Ind. (also called the “index” herd). The investigation process (referred to as epidemiology) requires reviewing purchase, sale and breeding records for all herds that are linked to the index herd in some way, including purchases of animals made more than 5 years ago. Reconstructing records for operations that are no longer in business can be a challenge and take a long time. TB is a slow-growing disease, and the animals involved could have been exposed years ago. The possibility exists that the ultimate source may never be definitively identified.
The source of infection for the most recent case (March 2011) has not yet been identified. The investigation into the disease’s origin is underway. The initial TB-positive cow was identified through routine surveillance at a slaughter facility. No direct links have been identified between the latest case and the positives identified on a cervid herd farm in Franklin County, Ind. in May 2009. The investigation process (referred to as epidemiology) requires reviewing purchase, sale and breeding records for all cattle operations linked to the index herd in some way, including purchases of animals made several years ago. Reconstructing records for operations that are no longer in business can be a challenge and take a long time. TB is a slow-growing disease, and the animals involved could have been exposed years ago. The possibility exists that the ultimate source may never be definitively identified.
