Study reveals TB spread risks

Cattle are ten times more likely to catch TB from badgers than badgers are to catch it from cattle, new research has shown.

But work led by scientists from the University of Edinburgh has also shown that either species is twice as likely to catch it from their own kind as they are to pick it up from the other species.

Experts this week claimed that the findings of the research – which was conducted in Gloucestershire over a 15-year period – could improve control strategies, reduce disease transmission and cut costs associated with the disease which has been a long-standing scourge for cattle farmers in many areas south of the Border. Bovine TB is an infectious respiratory disease of cattle that is mainly spread through inhaling infectious particles in the air. It is caused by the bacterium Mycobacterium bovis, which can also infect and cause disease in other mammals, including humans, deer, goats, pigs, cats and dogs.

Using data from an undisturbed population of badgers in a Gloucestershire hotspot and nearby cattle farms, the study provided the first direct evidence of transmission between badgers and cattle. The researchers analysed the entire genetic make-up of the bacteria from 230 badgers and 189 cattle and combined the results with detailed information on where the cattle and badgers lived, when they were infected, and whether they could have had contact with one another. And by estimating how often the two species spread TB the researchers found that badgers played an important role in the maintenance of the disease in this area.

Rowland Kao, professor of veterinary epidemiology and data science at the University of Edinburgh, said the work would “…allow for a more targeted control of tuberculosis in cattle and badgers, aiding efforts to control the disease and reduce the impact on the badger population”.