Usutu virus has been identified in Scotland for the first time, detected in blackbirds through the Animal and Plant Health Agency's national passive wild avian surveillance programme working alongside Mosquito Scotland, a research programme led by the University of Glasgow. The discovery traces back to the summer of 2025, when residents of the Isle of Arran reported a cluster of blackbirds showing neurological signs or found dead, prompting samples to be sent for testing.
A Glasgow-led field team travelled quickly to Arran and confirmed the presence of several mosquito species near the locations where infected birds were found, including species known to transmit Usutu virus. The virus has circulated in southeast England for six years, and its appearance so far north is a notable marker of how warming conditions are extending the range of mosquito-borne pathogens. The work involved APHA's vector-borne disease group and SRUC Veterinary Services.
No human cases of Usutu virus have been reported in the UK, and the public health risk is assessed as very low. For researchers, however, the detection underlines the value of combining citizen reports, veterinary surveillance and entomology: Scotland's mosquito season runs from April to October, and understanding which species are present, and where, is essential groundwork for anticipating the future spread of vector-borne disease in a changing climate.