The Department for Environment, Food and Rural Affairs (Defra) has announced changes to disease control measures for bluetongue as February 1 marked the beginning of a “seasonally low vector period”.
A seasonally low vector period means that midge activity is much lower, and they are not actively feeding due to the drop in temperature.
As a result, the department has made the decision to not cull infected animals where test results indicate older infection and there is a presence of BTV-3 antibodies.
The reduced risk from midges means that some restrictions on movements of live animals from the temporary control zones (TCZ) can now be eased if they meet certain conditions, including testing negative in a pre-movement test.
Some restrictions on movements of animals into and within the TCZ have also been eased.
Institute Fellow in vector ecology at the Pirbright Institute, Dr Marion England, said that current weather conditions mean that Cuilcoides – the type of midge able to spread viruses – are “highly unlikely” to transmit virus to livestock.
“Under these conditions, midges previously infected with BTV-3 are currently highly unlikely to transmit the virus,” she said.
“The most active period for midges is during the warmer months in spring, summer and autumn, and midges can become newly infected with bluetongue virus and spread disease when the weather is above 12° for a sustained period.
“Midges infected in late autumn 2023 are now not likely to be a risk for spreading disease because they usually die off during winter, and are not actively biting when temperatures are below 4°.”
There are currently 70 confirmed bluetongue cases in England on 43 premises across three counties.
Bluetongue
On the changes, Defra said: “The reduced risk from midges means that some movements of live animals out of the zone can now be temporarily permitted subject to pre-movement testing and that they meet certain licence conditions.
“These relaxations will only apply during periods of low vector activity and will not apply to animals that test positive in a pre-movement test.
“During this low vector activity period we will also ease the licence restrictions on movements of animals into and within the TCZs.”
The department said these restrictions will be revisited when vector activity increases again with warmer temperatures in March or April.
“We will keep the situation under review and provide further updates if circumstances necessitate a change in approach.”
Advice to farmers from Ruminant Health & Welfare (RH&W) remains three-fold: farmers need to beware, take action to report any signs and remain vigilant.
Farmers can call the bluetongue hotline to get advice or ask questions linked to the current situation on 024 7771 0386.
