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https://www.theguardian.com/science/2023/may/07/mosquitoes-repellant-bite-summer-science-medical-research>
"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.
Whether you get bitten or not is, in large part, a foregone conclusion: by some
estimates, genes account for 85% of a person’s propensity to be stung, while
DNA testing company 23andMe says it has identified 285 heritable genetic
markers responsible for their frequency, itchiness and size.
Mosquitoes are attracted to humans by volatiles (organic compounds) we emit in
our breath. But it is those we release through our skin that serve as signposts
to where they should feed from; chemicals we naturally produce, such as lactic
acid and ammonia. The more lactic acid your body produces, the worse the
feeding frenzy is likely to be. Given the limitations in changing our
physiology, repellants are, for now, really the only defence we have – bought
across the globe in such numbers that the market is predicted to reach $9bn
(£7.2bn) by 2026."
Cheers,
*** Xanni ***
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mailto:xanni@xanadu.net Andrew Pam
http://xanadu.com.au/ Chief Scientist, Xanadu
https://glasswings.com.au/ Partner, Glass Wings
https://sericyb.com.au/ Manager, Serious Cybernetics
