22 October 1999

Triplet trial aims to fill gaps in culling research

Too many questions on TB

remain unanswered for a

control policy to begin,

delegates at TB The Facts

conference were told.

Jessica Buss reports

KILLING all badgers is not a viable option for controlling cattle TB.

John Bourne of the Independent Scientific Group said the evidence the Krebs study and ISG analysed shows that if badgers are killed on a large scale it will have an impact on cattle TB.

"But thats not acceptable, and if badgers are culled on a small scale it may make the problem worse.

"We have to find middle ground, so cattle and badgers can live together," he told the conference.

The triplet trial now underway aims to find out whether reducing badger numbers will help and how responsible they are for transmission of TB to cattle.

In triplet trial sites badgers are being culled and collected for investigation into TB in badgers in one area; in a second area social groups of badgers are culled in response to cattle TB outbreaks; and the third area is a control area where there is no treatment.

But when questioned by the audience, Prof Bourne acknowledged that the last triplet site would not be cleared of badgers until 2001. It would then take five years to complete the study in that area.

The triplet sites were also dependent on trapping badgers, both for welfare reasons and because carcasses were needed for investigations into TB in badgers, he said. A live test was too unreliable to indicate true incidence and whether badgers with TB were infectious or had dormant infection.

But Prof Bourne admitted trapping only caught 80% of badgers in an area. This will be taken into account in the analysis of results, he said.

Other research could provide some advice on control or prevention of TB in the next two years, he added. This was likely to be from TB99 questionnaires being completed by producers in areas where there are breakdowns.

"We dont know from the previous TB49 questionnaire what the risk factors are. We accept TB99 is not easy to fill out, but its an important part of the study."

TBANDBADGERS

&#8226 Wait for research.

&#8226 Triplet study long-term.

&#8226 Questionnaire results in two years.

UNANSWEREDQUESTIONS

&#8226 What are the sources of TB infection and their relative importance?

&#8226 How are animals infected with the TB organism?

&#8226 What species is responsible for what proportion of disease transfer?

&#8226 What makes a herd susceptible to TB?

&#8226 How can we stop false negative results?

&#8226 Can husbandry help reduce risks?

&#8226 Will culling some badgers reduce or increase TB in cattle?