Warwick researchers predict spread of TB

Researchers at Warwick University have devised the first national model to predict the spread of Bovine Tuberculosis (bTB) in cattle herds.

Using a mathematical model, the researchers demonstrated that the pattern of the disease’s transmission followed multiple routes of transference including failed cattle infection tests, cattle movement and reinfection from environmental reservoirs.

This research is thus allowing key recommendations to be made to limit its spread.

Professor Matthew Keeling, from Warwick’s School of Life Sciences and the Department of Mathematics, commented on the recent breakthrough.

“Our model offers a dispassionate, unbiased view of the spread of bTB through the cattle industry of Great Britain. The model is based on the recorded pattern of positive and negative tests and uses the known movement of cattle around the country.”

The disease has been granted an epidemic status in England, with the number of herds “not officially TB free” having doubled in the last 10 years to 9,236 in 2013.

The disease may also cross species barriers and infect other domestic and wild animals. Although rare, bTB transmission to humans is also possible.

On average, costs for the bTB infection amounted to £14,000 for the typical farmer and £20,000 for the government. The slaughter of infected cattle, and the resulting compensation, blood tests, and movement restrictions all contributed to such costs.

The Warwick research has highlighted that only a small number of farms are likely to be responsible for much of the transmission. This is down to irregularities in the time lag between testing and diagnosis, or to inaccuracies within the tests themselves.

Whilst the government has invested in a system of detection and protection including tracking and testing, vast sums of money have been spent on widespread culls, even amongst badgers.

Professor Keeling remarked that: “Models such as ours can be combined with economic analysis to assess a wide range of future control options.”