Dengue fever: Dangerous mosquito-borne disease could arrive in England this century - thanks to climate change

Warmer temperatures mean that Asian tiger mosquitos carrying dengue fever and other tropical diseases could become established in England inn the next few decades, government health experts have warned.

Dengue fever - a virus found in many more tropical parts of the world - is spread by bites from an infected mosquito, and is not usually serious. But doctors warn that between one and 5% of patients may develop potentially fatal severe dengue, or dengue haemorrhagic fever.

The virus is spread by the Aedes family of mosquitoes. But climate change means that one species, the Asian Tiger mosquito, has now become widespread in southern Europe. It has also been detected by authorities at UK ports several times in recent years, but so far no local populations have become established. It is known for its striped body and its potential to spread dengue fever, zika virus and chikungunya – and the species tends to live in urban areas as opposed to wetlands and feed during the day, putting people at greater risk of being bitten.

In a new report about the health effects of climate change, the UK Health Security Agency (UKHSA) warned dengue fever could be transmitted in London by 2060 while the mosquito itself could become widely established across England in the 2040s. Officials also said other infectious diseases spread through food or water could become more prevalent, with the risk of future pandemics increasing.

“Things that when I trained many years ago were called tropical diseases will actually become national domestic diseases," UKHSA chief executive Professor Dame Jenny Harries told PA. Climate change was an important threat which undermines public health right across the globe, she continued, "not only by increasing the mortality burden of extreme temperatures and weather effects, but through enhancing the spread of infectious disease and exacerbating the fragility of the global systems that our health depends upon, increasing the vulnerability of populations to existing geopolitical, energy and cost-of-living crises".

“In the summer of 2022, UK temperatures reached above 40C for the first time on record. We had nearly 3,000 excess deaths recorded across that extended heat period while many other countries have experienced bouts of intense and prolonged heat in recent months."

This year is also set to be the hottest in recorded history, and Dame Harries said that using a high emission scenario, UK heat-related deaths were estimated to increase by over 100% in the 2030s, over 500% in the 2050s, and over 1,000% by 2070. Food prices were also likely to become more volatile as much of what the UK imports is from regions sensitive to climate impacts, such as drought.

The planet has already warmed by 1.2C above pre-industrial levels and the amount of carbon in the atmosphere means further warming is already locked in - even if emissions were to start declining immediately. This meant some adaption was necessary alongside cutting emissions - such as improving housing, flood defences, and the extreme temperature warning system would help to mitigate some of these growing dangers, the UKHSA said.

Researchers have previously warned dengue fever – a mosquito-borne disease normally associated with the tropics – is becoming more prevalent in parts of Europe due to climate change. A woman from the UK was infected while on holiday in the south of France in September 2022. The 44-year-old was infected with the tropical disease during a trip to Nice, and experienced fever, headache, muscle pain and a rash for three days - but did not require further medical treatment.

Jolyon Medlock, an entomologist at UKHSA, added that monitoring at borders can help slow the spread of mosquitos, and that at home people can keep them away by covering any standing water or empty containers as the insects lay eggs in them.