Global heating may leave UK open to more tropical diseases, experts warn

Climate breakdown could make the UK vulnerable to insect-transmitted tropical diseases that were previously found only in hot countries, scientists have warned, urging ministers to redouble efforts to contain their spread abroad.

- Anna Bawden

Leading mosquito experts said cuts to international aid would lead to a collapse in crucial surveillance, control and treatment programmes in endemic countries, leading to more deaths from tropical disease.

This week, the UK Health Security Agency announced the discovery of West Nile virus in UK mosquitoes for the first time. The agency said it had found no evidence of transmission to humans and the risk to the British public was low.

West Nile virus is transmitted by mosquitoes and like dengue fever, chikungunya and Zika, used to be confined to hotter regions of the world. But global heating has led to West Nile virus and other tropical diseases expanding into cooler areas, including parts of northern and western Europe.

In 2024, there were more than 1,400 human cases of locally acquired West Nile virus and several hundred cases of dengue, mostly in France and Italy.

According to Dr Robert Jones, an assistant professor at the London School of Hygiene & Tropical Medicine, in the most extreme scenarios - with temperatures rising by 4 to 5 degrees above pre-industrial levels - a five-fold increase in dengue and chikungunya outbreaks would be expected by the 2060s in Europe.