The earliest signs of summer herald my annual metamorphosis – from woman to lifesize pincushion. Whether at home or abroad, when mosquitoes begin their hunt for blood I am reminded, via a blanket of red blotches that have more than once swelled to the size of a golf ball, that mine is a godlike nectar. On a single day last December, a tropical Christmas trip quickly became a less-than-festive scratchathon after a glut of bites arrived, following which I was stung by jellyfish, then wasps. At this point, I can only assume the mosquitoes are giving other species ideas.
But there are signs that a solution for the 20% of the population who receive above-average numbers of bites may soon be at hand. Earlier this month, researchers at the Hebrew University of Jerusalem (HUJI) developed a new repellant capable of reducing the number of mosquitoes feeding by 80%. Applying a thin coating made from naturally occurring cellulose nanocrystals (CNC), a renewable raw material found in the likes of cotton and wood, and indole, an organic compound with an unpleasant odour, to skin served as “chemical camouflage”, said the study published in PNAS Nexus. This combination – which derails the cues that mosquitoes use to select their victims – is “unprecedented”, according to Jonathan Bohbot, a senior lecturer at HUJI and one of the paper’s co-authors. Indeed, the results are considered so promising that further human studies are planned, with a view to having the coating approved by regulators ahead of commercial use. “The CNC-repellant combination will have a longer efficacy and range of action than other products currently available on the market,” says Bohbot, adding that they expect “high levels of product adoption” if and when it does hit shelves.
