Bluetongue cases in Ireland rise to 39 as Wexford leads outbreak

Ireland has confirmed 39 bluetongue cases, with Co. Wexford now the worst-affected county in the country. The Department of Agriculture, Food and the Marine (DAFM) released the updated figure on Tuesday, October 20, confirming the outbreak continues to widen during the highest-risk window for midge-borne transmission.

The case profile remains overwhelmingly bovine. Of the 39 detections, three are in sheep. Co. Wexford alone accounts for 15 of them: 14 bovine cases and one sheep case. That concentration gives the south-east county the unenviable position of outbreak epicentre, and it places livestock keepers there under the sharpest scrutiny for clinical signs.

Why the timing matters

Ireland sits inside the traditional high-risk period for bluetongue spread, which runs from April to November. The virus moves through infected biting midges of the Culicoides species, and many of those species live throughout the island of Ireland. Midge activity depends on average temperatures, which means the risk curve tracks the weather.

That relationship is shifting. Rising global temperatures and mild winter conditions may keep midges active for longer, extending the periods in which the virus can transmit between animals. Wind speed and direction add another variable: they determine how far midges can travel and could accelerate spread into previously unaffected areas.

What is driving the wider risk?

Bluetongue is currently present across many parts of Europe. Historically, the disease — driven by serotypes 1, 4 and 8 — appeared more often in southern Europe, where warmer climates suit the vector.

That geography has changed. Since autumn 2023, a new serotype, BTV-3, has spread across mainland Europe and Great Britain, raising the risk of introduction into disease-free areas. Only a small number of countries and territories, mainly in eastern Europe, remain free of the disease.

For Irish farmers, the BTV-3 spread matters because it sits close to home. Movement of the virus through Britain and the continent has shortened the distance between the outbreak frontier and Irish herds. Midges carried on wind currents do not respect trade barriers.

What should farmers watch next?

The immediate question is how far the case count climbs before midge activity falls with winter temperatures. If mild conditions persist, as DAFM's guidance on extended vector activity suggests they may, the transmission window could run longer than the traditional November cut-off.

Livestock keepers in Wexford and neighbouring counties should watch for clinical signs in both cattle and sheep, given that both species have now tested positive nationally. The three sheep cases confirm the virus is not confined to bovine holdings.

The next DAFM updates will show whether the Wexford cluster stabilises or seeds further detections elsewhere. Farmers should also monitor department guidance on vaccination, which has emerged as the principal control response elsewhere in Europe. The weeks between now and the first sustained frost will decide whether Ireland closes this outbreak season at 39 cases or well beyond it.