Mosquitoes bring diseases to UK

BBC and Sky News articles recently reported a climate change study that predicts an increase in mosquito-borne diseases in the UK.

Photo: Katja Schulz

The British climate of rising temperatures, with wetter weather and milder winters, are now suitable for mosquitoes that carry West Nile virus. It is predicted that mosquitoes that carry the Dengue Fever and Chikungunya virus will also be entering the UK by 2030 according to a climate change study, published in The Lancet: Infectious Diseases journal, by the emergency response department at Public Health England.

There have already been cases of Dengue Fever, Chikungunya and malaria in Europe in the last few years.

Dr Jolyon Medlock, joint author of the report and head of medical entomology at Public Health England said warmer temperatures and more rain, as a result of climate change, provide ideal conditions for mosquitoes. Mosquitoes breed and develop faster at higher temperatures (flying faster & more adroitly) and milder winters mean they won’t be killed off in the UK. This means by the summer they are much more abundant.

While drier summers make it difficult for mosquitoes to survive, they can survive in water butts and ponds in gardens. Mosquitoes often lay eggs in places that have been flooded.

Climate change simulation models showed a 2C rise in temperature would extend mosquito season by one month and extend their geographical area by 30% by 2030. This would make temperatures ideal for mosquitoes that spread Chikungunya and Dengue Fever. The model also predicted a seasonal increase in the number of ticks in the UK countryside.

Culex mosquitoes lurk underground!

The Culex species of mosquito, known as the main carrier of West Nile virus in Europe, has already been discovered in Kent and Essex in the last few years. The Culex pipiens molestus also lives in the London Underground!

The West Nile virus is a flu-like disease and most cases are not serious, but in rare cases (less than 1%) it can include infection of the brain or spinal cord which can be fatal. No human cases of the virus have occurred in the UK although there have been cases in eastern Europe.

A bigger threat is the Asian tiger (Aedes albopictus) mosquito, which spreads Dengue Fever and Chikungunya. Cases of these have been found in Italy and France in the last few years, as well as malaria in Greece, France & Spain.

These Asian species are thought to be imported into the UK from Asia through the global trade of tyres, fruit containers and anything that is transported with water-based liquids. Mosquitoes can even get into sealed water tanks on ships.

The report underlined climate change is not the only factor contributing to vector-borne diseases in the UK. The authors of the report emphasised the need to assess the risks and factors and prepare for future outbreaks of mosquito-borne diseases.

The only way to prepare for the risk of more and more mosquitoes in the UK is to be ahead of the game and prepare your defence by avoiding mosquito bites.

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References

“Mosquitoes Heading for Warmer UK – Experts.” Sky News, Web.

“Mosquitoes ‘could bring exotic diseases to UK’.” BBC, Web.

“Effect of climate change on vector-borne disease risk in the UK.” Dr Jolyon M. Medlock, PhD, Steve A Leach, PhD, The Lancet: Infectious Diseases, Web.