Climate change could make the UK vulnerable to insect-borne tropical diseases previously confined to hot countries, scientists have warned. They urge ministers to bolster efforts to contain these diseases abroad, warning that cuts to international aid could undermine surveillance and control programmes in endemic regions.
The UK Health Security Agency recently detected West Nile virus in UK mosquitoes for the first time, though no human transmission has been found. Global heating has expanded the range of West Nile virus, dengue, chikungunya, and Zika into cooler areas, including parts of Europe. In 2024, Europe saw over 1,400 locally acquired West Nile cases and several hundred dengue cases, mainly in France and Italy.
Dr Robert Jones of the London School of Hygiene and Tropical Medicine said that in extreme warming scenarios, dengue and chikungunya outbreaks in Europe could increase fivefold by the 2060s. While a dramatic surge in the UK is unlikely, rising temperatures could make the country more hospitable to disease-carrying insects, potentially leading to West Nile virus epidemics by the second half of the century.
Currently, the UK lacks sufficient populations of the right mosquitoes for sustained transmission. However, as temperatures rise, local mosquito populations are changing, which could enable local transmission of tropical diseases, especially in southern England. Experts stress that controlling these diseases overseas is crucial for UK protection, as infectious diseases do not respect borders.
Professor Heather Ferguson of the University of Glasgow emphasised that investing in disease control in tropical countries is the top priority, noting that malaria still kills a child under five every minute. She warned that cuts to foreign aid would lead to more deaths from tropical diseases and undermine global elimination efforts.
