Mosquitoes could bring diseases such as dengue fever and West Nile virus to the UK within the next few decades, experts have warned. Writing in The Lancet Infectious Diseases journal, scientists from Public Health England said warmer UK temperatures could make conditions favourable for the insects to breed.
There are already 34 different species of mosquito in the UK, and in parts of Europe, mosquitoes and ticks are on the rise. Over the past decade, malaria has spread to Greece, West Nile virus to eastern Europe, and chikungunya to Italy and France.
The report said warmer temperatures in the UK could provide ideal conditions for the Asian tiger mosquito (Aedes albopictus), which spreads dengue and chikungunya. Using climate change modelling, the report predicted that seasonal activity of ticks, mosquitoes and parasites could increase if temperatures rise by more than a few degrees, particularly in southern England.
However, the report conceded that the direct effects of climate change could not be predicted confidently. The British climate is already suitable for West Nile virus transmission, but no human cases have been reported so far.
Dr Jolyon Medlock, head of medical entomology at Public Health England, said all invertebrates are affected by temperature changes. 'They develop faster at higher temperatures, so during a mild winter they won't be killed off,' he said. He noted that mosquitoes often lay eggs in flooded areas, and species originating in Asia have probably been imported through the global trade in used tyres.
The report emphasised that climate change is just one of many factors influencing the spread of vector-borne diseases, alongside urbanisation, land use change, migration and globalisation. The authors stressed the need to assess risks and prepare for future outbreaks.
