Washington - A lucky few people seem immune to the bites of mosquitoes. Others can’t seem to avoid them.
New research explains mosquitoes’ apparent selectivity. According to an article in Smithsonian magazine, an estimated 20 percent of people are “especially delicious” to mosquitoes, and they are bitten more often than others.
Why? A number of factors are at play. Chief among them is blood type. “Not surprisingly – since, after all, mosquitoes bite us to harvest proteins from our blood – research shows they find certain blood types more appetising than others,” says the article.
Type O is at the top of the list. Additionally, about 85 percent of people secrete a chemical signal that indicates their blood type; these “secretors” are more prone to bites, regardless of their blood type.
Another factor is the amount of carbon dioxide people emit when they breathe. Larger people exhale more of the gas, which may explain why adults tend to get bitten more often than children. This also means obese people are more prone to getting bitten than average or underweight people, tall people more prone than short.
Sweat, high body temperatures and skin bacteria also play a role.
Pregnancy, which increases body temperature and carbon dioxide emission, may also increase the likelihood of bites.
And if you have a beer at a braai, you may make yourself a mosquito target. No one has been able to pinpoint why this is.
Some have theorised that the elevation in body temperature and the amount of ethanol in sweat may play a role, but neither theory has panned out. Still, it appears that even a small bottle is enough to do the trick. – The Washington Post