Question to the Department for Environment, Food and Rural Affairs:

To ask the Secretary of State for Environment, Food and Rural Affairs, with reference to the UK Health Security Agency news announcement of 21 May 2025, how much he has spent on testing mosquitoes through the Vector-Borne Real-time Arbovirus Detection and Response programme; and what the Ct value was for the PCR tests which located fragments of the West Nile virus in two mosquitoes.

The Vector-Borne RADAR (Real-time Arbovirus Detection and Response) programme is a three-year funded collaborative grant worth £1.15 million which is 80% funded by Defra / UK Research & Innovation, and 20% by each of the collaborative organisations, the Animal and Plant Health Agency, the British Trust for Ornithology, the Institute of Zoology and the UK Health Security Agency.

Approximately 50,000 mosquitoes across 6,000 pools in 2023 and 2024 combined have been screened from across southern and eastern England.

The programme retrospectively screened 2,000 Aedes vexans mosquitoes that were trapped in Gamston, Nottinghamshire in July 2023. These were split into 200 pools of 10 mosquitoes and screened using three separate rt-PCRs. Two pools were positive for West Nile virus (WNV) RNA (Ct values 30.7 -33.4 across all three PCRs).

More significantly, the positive RNA extracts were also submitted for GridION sequencing (an Oxford Nanopore based system). One pool amplified a 402bp region of the WNV genome, with a read depth of c500 reads which generated a consensus sequence showing a conserved section of the WNV genome and clusters with WNV lineage 1a sequences from Europe, the Middle East and North America.