Bovine TB infection status in cattle in Great Britain in 2023.

In 2023, 3078 cattle herds experienced a new bovine tuberculosis (TB) incident out of a total of 68,895 registered cattle herds in Great Britain (GB). This was a 13.6 per cent decrease in the number of new TB incidents and a 3.3 per cent decrease in the number of registered herds compared with 2022. Similarly, the number of TB incidents in England fell by 16.9 per cent and the number of herds reduced by 4.3 per cent. In Scotland, there was also a decline in the number of TB incidents (-18.2 per cent) and herds (-0.5 per cent). In contrast, Wales experienced a 2.3 per cent increase in the number of new TB incidents, and a 2.0 per cent decrease in the number of herds. In GB the herd incidence rate of TB decreased for the third consecutive year, with 6.5 new cases per 100 herd years at risk (100 HYR) in 2023, compared with 7.2 in 2022 (incidence rate ratio [IRR]=0.90, P<0.001). Similarly, the herd incidence rate in England decreased significantly in 2023 compared with 2022, from 8.4 to 7.3 new TB incidents per 100 HYR (IRR=0.87, P<0.001). This decrease was mainly observed in the High risk area. The herd incidence rate in Wales increased non-significantly in 2023 compared with 2022, from 6.5 to 6.8 incidents per 100 HYR (IRR=1.05, P=0.38). Changes in incidence rate were not universal across Wales TB areas, with a significant increase observed in the High TB Area West, and a significant decrease in the Intermediate TB Area North. Scotland remained Officially TB Free in 2023, with an annual herd incidence rate of 0.6 TB incidents per 100 HYR, slightly lower than in 2022 (0.7) (IRR=0.84, P=0.51). At GB level, there was a slight decrease in TB prevalence from 3.9 per cent in 2022 to 3.6 per cent in 2023. TB prevalence in England in 2023 declined in all TB risk areas relative to 2022. There was a small increase in TB prevalence in Wales in 2023 (5.4 per cent) compared with 2022 (5.3 per cent). TB prevalence in Scotland remained unchanged between 2022 and 2023 (0.1 per cent).