West Nile Virus Detected in UK Mosquitoes for the First Time

London, May 21, 2025 – Health officials in the UK have confirmed the first-ever detection of West Nile virus in British mosquitoes. The virus, which can cause serious illness and even death, has never been found in UK insects before.

The UK Health Security Agency (UKHSA) said the virus was discovered in Aedes vexans mosquitoes, a species that lives in Britain. These infected mosquitoes were found near the River Idle, close to Gamston village in Nottinghamshire.

What Is West Nile Virus?

West Nile virus mostly affects birds. It spreads through mosquito bites, especially from mosquitoes that bite both birds and humans. It is common in Africa, the Middle East, and South Asia but rare in Europe.

This is the first time UK scientists have found the genetic material of the virus in mosquitoes collected in Britain. The samples came from a joint study by UKHSA and the Animal and Plant Health Agency (APHA) in 2023.

Is There a Risk to the Public?

According to UKHSA, the risk to the public is very low. The virus does not spread from person to person, and only one in five infected people get symptoms.

What Are the Symptoms?

Symptoms may include:

• Fever

• Headache

• Tiredness

• Skin rash on the body, neck, and limbs

Most people recover in a few days or weeks. However, less than 1% of infected people develop West Nile neuroinvasive disease (WNND) — a severe brain infection. This can cause:

• Seizures

• Disorientation

• Coma

• Paralysis

The death rate for WNND is between 3% and 15%, especially in older adults, young children, or those with weak immune systems.

How to Stay Safe

To protect yourself from West Nile virus, health officials advise:

• Wearing insect repellent

• Using long-sleeve clothing in the evening and early morning

• Removing standing water around your home (where mosquitoes breed)

The UKHSA says it will share guidance with healthcare professionals to monitor any future risks.

This is a serious but low-risk situation. The discovery of West Nile virus in British mosquitoes is a wake-up call for better mosquito control and public awareness. UK health officials are working quickly to monitor and prevent any spread to humans.