West Nile Virus Found in UK Mosquitoes for First Time: Climate Change Tied to Spread

For the first time, West Nile virus has been identified in mosquitoes within the UK, with increasing temperatures elevating the likelihood of vector-borne illnesses becoming more prevalent across Europe.

So far, there haven’t been any human cases in the UK, and the risk to the general public remains “very low,” as stated by the UK Health Security Agency (UKHSA).

However, the agency is increasing monitoring efforts and instructing physicians to test specific patients whose medical problems might be connected to the virus.

The agency reported that traces of West Nile virus were detected in two batches of mosquitoes gathered from wetland areas in Nottinghamshire in July 2023. Additionally, out of another 198 sets of mosquito samples taken from the same location, all tests came back negative for the virus.

"Although this is the initial discovery of West Nile virus in mosquitoes within the UK, it was anticipated since the virus has become prevalent across Europe," stated Dr Meera Chand, Deputy Director of Travel Health, Zoonoses, Emerging Infections, Respiratory and Tuberculosis at UKHSA, in an official release.

West Nile, which belongs to the same virus family as dengue And yellow fever, which is frequently encountered in birds, spreads via mosquito bites. Although people can get infected, roughly 80 percent of them won’t show any signs of illness.

The virus was initially discovered in Uganda back in 1937, and it is frequently encountered in Africa, the Middle East, North America, and Western Asia.

Linked spread to climate change

It has been appearing more often in northern and western Europe In recent times, as milder temperatures linked to climate change make the area more welcoming for mosquitos.

Dr Arran Folly, an arbovirologist at the UK’s Animal and Plant Health Agency (APHA), stated, "The discovery of West Nile virus in the UK reflects broader shifts occurring globally. As a result of climate change, regions previously unaffected are now seeing the spread of mosquito-transmitted illnesses."

Where the West Nile virus is prevalent, infections typically occur during the summer season. Often, individuals experience either no symptoms or only minor ones similar to those of the flu; however, in uncommon instances, it may result in severe conditions like encephalitis or meningitis.

In light of the virus' detection in the UK, doctors are being advised "as a precaution" to run additional tests on people with unexplained brain swelling, or encephalitis, the UKHSA said.

There is no vaccine or targeted treatment for West Nile virus.

James Logan, a professor of medical entomology at the London School of Hygiene and Tropical Medicine, urged public health and veterinary officials to enhance monitoring efforts to "get ahead" of the virus.

Logan stated in a release, "This is an opportunity to acknowledge that the UK is now vulnerable to certain illnesses previously thought of as 'tropical'."

"We are entering an era where we must learn to live smarter in a bug’s world".