June 7, 2023

Cattle-to-cattle transmission of bovine tuberculosis more common than badger-to-cattle transmission, study reveals

A recent study conducted by the Agri-Food & Biosciences Institute (AFBI) in the UK has found that the transmission of bovine tuberculosis (bTB) among cattle is "considerably more common" than transmission from badgers to cattle, BBC reported.

The research analysed genetic data of the bacterium responsible for bTB transmission, and was carried out as part of a five-year Test, Vaccinate or Remove (TVR) project in County Down, Northern Ireland which included selective badger culls.

The AFBI study generated a vast amount of genetic data, totaling 162 gigabytes. By examining this data, the researchers uncovered patterns of bTB transmission within and between cattle and badger populations in the TVR zone near Banbridge.

The findings indicated that cattle-to-cattle transmission was the most prevalent form of disease spread observed, while badger-to-badger transmission was not detected. The scientists did detect instances of transmission between cattle and badgers, but cattle-to-badger transmission appeared to be more common than badger-to-cattle transmission, albeit with significant variation.

According to AFBI, the evidence suggests that cattle play a major role in spreading the disease in the TVR zone, with badgers involved to a lesser extent. But the study acknowledged that when badger-to-cattle transmission occurs, it can amplify within a herd and have a greater impact. There remains a possibility that even a small amount of infection from badgers to cattle could have a disproportionate effect.

The researchers highlighted the increasing importance of using genomics for disease surveillance, drawing parallels to its widespread use during the COVID-19 pandemic. They believe that genomics will play a crucial role in bTB control in the future.

In March 2022, the then-agriculture minister Edwin Poots announced a strategy to tackle Bovine TB in Northern Ireland, which included a proposal for a badger cull. However, the implementation of the cull is currently facing legal challenges.

-      BBC