Following the discovery of what is believed to be maternal transmission of BTV8 to calves born to imported dams in Northern Ireland, emergency research has been instigated to assess the dangers of this transmission route.

The work will be carried out at the Institute for Animal Health, Pirbright, in conjunction with Animal Health Bury St Edmunds and the Vet Lab Agency, and will look into whether this is an effective overwintering method for the virus and what the reproductive effects of this could be.

This process of transplacental transmission would provide an effective “overwintering” mechanism for BTV8.

Virus-positive calves or lambs might, therefore, be born this spring just in time for the new midge season, and act as a reservoir for re-emergence and further spread of the virus, explains Karin Darpel of the Arbovirology unit at IAH.