Invasive Aedes aegypti mosquito breeds in east London

The tropical mosquito species Aedes aegypti has been found breeding in homes in east London. This marks the first confirmed breeding of the species in the United Kingdom.

Normally found in tropical and subtropical regions, Aedes aegypti can transmit dengue, chikungunya, and Zika viruses in countries where these diseases circulate. While rarely fatal, these illnesses can cause complications. Zika virus is linked to serious problems during and after pregnancy.

The UK Health Security Agency (UKHSA) stated the risk to the public from this discovery is low. There is no evidence the mosquitoes in east London have caused human infections.

Discovery and source

The initial finding was reported through the UKHSA's mosquito watch surveillance scheme. The agency said the insects could have entered the UK in vehicles, baggage, or imported plants. If they find a suitable climate, they can survive.

The agency confirmed that despite evidence of breeding, the species is not established in the UK. The typical UK climate is too cold for them to survive for long.

Climate change warnings

However, the UKHSA warned that in a warming climate, "we will continue to see incursions of invasive mosquitoes, and increased reports of them being able to survive in the UK". David Smith, advocacy and social change manager at the charity Buglife, said the rapidly warming climate is creating more favourable conditions for exotic and potentially invasive species to establish in the UK.

A study earlier this year found that chikungunya, an excruciating tropical disease, can now be transmitted in most of Europe because of higher temperatures caused by the climate crisis. That analysis was the first to assess the effect of temperature on the virus's incubation time in the Asian tiger mosquito.

Smith linked the discovery to broader biosecurity concerns. "Recent reports of non-native invertebrates, including mosquito species, highlight the urgent need for the government to strengthen biosecurity, improve surveillance and address pathways such as the movement of potted plants and soils, through which numerous invertebrates can hitchhike undetected," he said.

Response and public advice

The UKHSA said control measures have been implemented to destroy the larvae. The area will continue to be monitored closely to identify and eradicate any further mosquitoes and larvae.

The agency advised residents to remove standing water from gardens and outdoor spaces. This includes water in buckets, containers, paddling pools, and plant pots. Removing these water sources reduces opportunities for all mosquito species to breed. This is the fourth time the Aedes aegypti species has been detected in the UK.