Spanish lab sterilises mosquitoes as climate change fuels spread of dengue fever

NAQUERA, Spain - A Spanish laboratory is breeding and sterilising thousands of tiger mosquitoes to fight dengue fever and other diseases as climate change encourages the invasive species to spread across Europe.

Using an electron accelerator, the regional government-funded Biological Pest Control Centre in Valencia sterilises and releases about 45,000 male mosquitoes every week so they can pair with females - whose bite transmits diseases among humans - and eventually reduce the overall mosquito population.

"It's a species that is becoming more common with climate change ... There is a favourable environment for its development for longer periods of time throughout the year and its populations are increasing all the time," said Vicente Dalmau of Valencia region's health, agriculture and fisheries department.

The specimens for reproduction come from the region, and scientists then use a machine to separate female pupae from the males, before using radiation to sterilise the males.

Sterilisation techniques have been used in other parts of the world but the lab, using its experience with fruit flies, is pioneering their use on tiger mosquitoes in Europe at a time of growing concern over a rise in mosquito-born diseases such as dengue, zika and chikungunya.

[[nid:651365]]

Data from the European Centre for Disease Prevention and Control shows an increase in cases imported from regions where dengue is endemic, as well as an increasing number of local outbreaks of West Nile virus and dengue in Europe.

The striped tiger mosquito, or Aedes albopictus, is spreading north, east, and west in Europe, and now has self-sustaining populations in 13 countries, including Spain.

The World Health Organisation said last year that dengue rates were rising globally, with reported cases since 2000 up eightfold to 4.2 million in 2022, as a warmer climate is thought to help the mosquitoes multiply faster.