New weapon in war on mosquitoes

12 September 2013 09:06

Mosquitoes have long been the enemy of holidaymakers

Mosquitoes have long been the enemy of holidaymakers

Holidaymakers could in future make themselves invisible to dreaded mosquitoes - and it will all be down to a substance that occurs naturally in human skin.

Scientists at the American Chemical Society meeting revealed they have discovered compounds in the skin which can block mosquitoes' ability to sniff out potential targets to feast on.

To test the theory to the extreme, they put a hand containing the chemicals inside an enclosure which was filled with the hungry insects - and discovered the skin was completely ignored.

As well as helping holidaymakers avoid bites while overseas, the discovery also has the potential to stop the spread of deadly diseases for which the insects are so often responsible.

One such disease is malaria, which the World Health Organisation said killed about 600,000 across the world in 2010 and is a particular problem in the developing world. When travelling in parts of the world where malaria is prevalent, it is always advisable to take out medical travel insurance for the trip.

The repellent Deet is currently heavily used to ward off the insects, but Ulrich Bernier of the United States Department of Agriculture, who presented the research, said his team was investigating alternatives to Deet as some people cannot use it and some studies have indicated it is losing its effectiveness.

"Repellents have been the mainstay for preventing mosquito bites... [but] we are exploring a different approach, with substances that impair the mosquito's sense of smell. If a mosquito can't sense that dinner is ready, there will be no buzzing, no landing and no bite," said Dr Bernier.

People often joke that mosquitoes are more attracted to some people than others, and Dr Bernier's research has now in effect backed up that theory.

His team has identified chemical components secreted naturally in the body that can hide the human smell from the insects.

To see which smells attract mosquitoes, the team sprayed different substances on to one side of a cage.

Dr Bernier and the other experts paid particular attention to compounds that did not seem to attract the insects. They then tested those compounds further by spraying them on to a human hand - and discovered the bugs did not even attempt to bite.

He explained that those compounds were found to have blocked the mosquitoes' sense of smell.

The team now believes the compounds could be added to lotions to keep the insects at bay.

James Logan, of the London School of Hygiene and Tropical Medicine, told BBC News: "If a new repellent can be developed which is more effective, longer lasting and affordable, it would be of great benefit to travellers and people living in disease endemic countries."

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