Although not backed up by spoligotype data, much was made of a couple of lightweight studies which examined cattle movement data from 2002 and 2003, immediately after Foot and Mouth restocks - data which carried a health warning for the rest of us 'Do Not Use' - and concluded cattle were responsible for spreading Tb.
If a cow has Tb when she steps onto a cattle lorry, she is unlikely to have a miraculous recovery during the journey. The question of course should be, has she been the cause of onwards transmission of bTb? And if cattle are not the cause of an outbreak of this infectious disease, what is? New work by the team at Stirling, based on 2004 data, concludes that in around 75 % - yup that's right, SEVENTY FIVE PERCENT of cases - the cause of bTb outbreaks is not cattle movements, neither local nor national.
In an abstract now published, a piece entitled:
"Estimates for local and movement-based transmission of bovine tuberculosis in British cattle" concludes that 75% of bTb outbreaks were caused by what is quaintly described as 'local effects'. A new word for badgers perhaps?
The authors point out that "Both badgers and livestock movements have been implicated in contributing to the ongoing epidemic of bovine tuberculosis (BTB) in British cattle. However, the relative contributions of these and other causes are not well quantified".
We used cattle movement data to construct an individual (premises)-based model of BTB spread within Great Britain, accounting for spread due to recorded cattle movements and other causes. Outbreak data for 2004 were best explained by a model attributing 16% of herd infections directly to cattle movements, and a further 9% unexplained, potentially including spread from unrecorded movements.
So, using 2004 data on actual bTb outbreaks and matching that to cattle movements on to the farm, both local and national (should there have been any) the team found that just 16% could be attributed to such 'On' movements, with a further 9% unexplained. They explain that the model which best matched the actual circumstances on farm assumed low levels of cattle-to-cattle transmission and continue:
The remaining 75% of infection was attributed to local effects within specific high-risk areas.
Pointing out that "Annual and biennial testing is mandatory for herds deemed at high risk of infection, as is pre-movement testing from such herds", the Stirling team confirm that
"herds identified as high risk in 2004 by our model are in broad agreement with those officially designated as such at that time".
In other words, what was actually happening on the ground, was predicted by the modeling exercise which they used.
And of these outbreaks, three quarters were attributed neither to local cattle movements nor national. But to 'local effects'. And a name they dare not speak.