One in five roadkill badgers tested positive for bovine TB

Prof Bennett said while these findings strongly suggest both badgers and cattle were part of the same geographically expanding epidemic in Cheshire, the direction of any cross-species transmission and the drivers of this expansion cannot be determined from this study.

He said: "Determining whether or not badgers on the edge of the cattle epidemic have TB is the first step in unpicking this tangle of cause and effect, and examining badgers that had already been killed on the roads seemed the obvious way to collect the evidence for this pilot study."

At the time of planning the project, bTB in cattle in much of Cheshire was regarded as sporadic and it was intended that the study investigate bTB in badgers ahead of the epidemic front.

2014 saw large increase in recorded bTB outbreaks in Cheshire herds, over a wider area than in previous years.

Another Cheshire farmer, who did not want to be named, added: “Those of us who were farming around bTB, especially in the east of the county, were seeing breakdowns typical of anywhere in the South West and not what you would expect of a cattle only issue.

"We expected a badger infection level similar to counties in the South West, where badgers had long been implicated in disease spread.

“I would not say we were glad to find they were infected, but it did mean that we as farmers may be believed now, because we had evidence that it was not just cattle.”

Gloucestershire vet Roger Blowey, who has been TB testing cattle for 50 years, said: “It was a superb idea to see if TB in badgers tracked ahead of TB in cattle, but bTB unfortunately has overtaken the project. Ideally the survey should be repeated further away from the Edge area for example where the Low Risk Area joins the Edge.

“If the prevalence of TB slowly rises in the badger population before it rises in cattle, then we have the answer.

“It would be interesting to analyse the current data in more detail, and geographically on an area basis within the Edge, to see if badger TB ran ahead of cattle TB, or whether cattle TB moves geographically ahead of badgers.

"The fact that 20 per cent of all badgers had TB compared with 0.05 per cent of the cattle in the same area might in itself suggest that the former was correct, i.e. badgers then cattle.”

Mr Blowey highlighted the case of Thornbury, South West England, where the badger cull in 1975-81 removed all badgers and, as a result, saw no bovine TB in the area for 10 years.

“TB recolonised the cull area. When the TB did start to reappear, you can see that it started from the edges and slowly moved across the area,” he added.

The results of the study were published today (December 6), in Scientific Reports.