For the first time, invasive Aedes aegypti mosquitoes and their larvae have been discovered breeding at residential properties in East London. Health officials stress that the public risk remains very low, though experts warn that warming UK temperatures are increasing the likelihood of tropical mosquito incursions.
East London Discovery Marks a UK First for Mosquito Breeding
The UK Health Security Agency (UKHSA) detected the insects through its Mosquito Watch surveillance scheme, marking the first time the species has been documented breeding in the country. While the exact addresses have not been made public, reports indicate the insects were found at residential properties featuring well-kept gardens and potted tomato plants. This discovery represents the fourth modern-day detection of Aedes aegypti in the UK.
Control measures have been implemented to destroy the larvae and prevent the insects from establishing a permanent foothold. Officials emphasize that these mosquitoes likely arrived as accidental hitchhikers in vehicles, baggage, and imported plants.
Assessing Public Health Risk and Disease Transmission
Known as the yellow fever mosquito, Aedes aegypti is capable of transmitting tropical viruses such as dengue, chikungunya, yellow fever, and Zika. However, authorities reiterate that the immediate danger to people in the area is minimal.
There is no evidence that these mosquitoes have caused human infections and importantly, to date, there is no evidence of the mosquitoes or larvae being detected in nearby public areas.
Because these viruses do not typically circulate in Britain, the chance of local contraction remains low.
Climate Warming Accelerates Invasive Species Incursions
Although historical climate conditions in Britain have been too cold for tropical mosquitoes to survive through winter, warming summers are altering that trajectory. Previous government modelling suggested such mosquitoes would be unlikely to get a foothold in Britain until 2040, but recent heatwaves and rising temperatures may accelerate that timeline.
Researchers point out that warmer conditions can accelerate mosquito development and increase the rate at which viruses such as dengue or chikungunya replicate within a competent mosquito. While the UK’s overall climate remains too cold for long-term survival, experts expect similar incursions to persist.
It is expected 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.
Dr Jolyon Medlock, head of medical entomology and zoonoses ecology at the UKHSA
Scientists have found eggs of the Aedes aegypti mosquito in the UK for the first time – a mosquito that spreads many tropical diseases. The eggs were recently discovered in a trap at a freight depot near Heathrow airport and confirmed by DNA testing to be Ae aegypti. The discovery, led by the UK Health Security Agency, also reported further findings of Aedes albopictus, the “Asian tiger” mosquito, at a site in Kent in summer 2024. Both species are invasive and thrive in warm, humid conditions. These Aedes mosquitoes matter because they can spread viruses such as dengue, chikungunya and Zika. Outbreaks of these diseases, once confined to the tropics, are now appearing in Europe. In 2024, Italy recorded over 200 locally acquired dengue cases, mainly in the Marche region, while France and Spain also reported domestic dengue transmission. Chikungunya has become another European concern, with France reporting nearly 500 locally transmitted cases in 2025. Zika has not yet taken hold in Europe, but the same mosquito species could carry it if conditions allow. Two related viruses, West Nile and Usutu, are also spreading further north across Europe. West Nile virus has caused outbreaks in birds, horses and people across Europe, and has now been detected in the UK for the first time. In summer 2023, scientists found West Nile virus genetic material in wild mosquitoes from samples collected in Nottinghamshire. Usutu, which mainly infects birds, was first detected in London blackbirds in 2020.
Surveillance Networks and Citizen Science Efforts
The UKHSA maintains a surveillance infrastructure coordinated by its Medical Entomology and Zoonoses Ecology team. When invasive mosquito eggs are found, entomologists and Environmental Health Officers inspect potential breeding grounds. Residents can assist ongoing monitoring by eliminating standing water in gardens and reporting findings through the UKHSA’s Mosquito Watch surveillance scheme.
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