The number of individual cattle coming up as reactors at TB tests has increased steadily throughout the year, to hit a record high in the latest figures published by DAERA for September 2024.

The data shows that annual animal incidence rate in September was 1.16%. In other words, for every 100 cattle presented at a TB test in the last 12 months, 1.16 showed up as reactors.

Animal incidence rate started out 2024 at 0.98% and it rose to 1.1% by June. Previously, it has consistently stayed below 1% across the DAERA dataset, which goes back to 2002. In 2010, the rate was down at 0.4%.

It is also important to note there is significant variation across NI. The highest animal incidence continues to be seen in the area covered by Enniskillen Divisional Veterinary Office (DVO), with the rate over the last 12 months at 1.77%. Newtownards DVO is next at 1.5%, followed by Omagh, Newry and Dungannon DVOs, all of which have rates over 1%.

With high individual animal rates of disease, it is no surprise that total TB reactor numbers in 2024 are also at record highs. To the end of September 2024, a total of 14,748 cattle have been removed off farms, up 21% on the same period in 2023 and 27% more than the equivalent figure in 2022. Back in 2010, just 4,701 reactors were found at TB tests over the same nine-month period.

Herd incidence

While the animal incidence figure has spiked since the start of the year, the herd incidence figure has remained fairly consistent at around 10.2%.

Annual herd incidence is a measure of new reactor herds as a proportion of all herds tested over the last 12 months. Given the number of herds already with the disease, it is becoming a less relevant figure.