FENDING OFF MOSQUITOES
Why do some people get bitten so much more than others?
Summertime means mosquito time — whether you’re travelling abroad or not. But why do some people return from a vacation or even an evening in the garden covered in bites, and others don’t? Can you really stop the itching? Here, two leading mosquito experts answer everything you need to know about the buzzing bloodsuckers.
Do Mosquitoes prefer some people to others?
“Absolutely yes,” says Adam Hart, an entomologist at the University of Gloucestershire who admits to being one of the lucky ones, escaping the worst of it in southern Africa while his colleagues are eaten alive.
How attractive you are to mosquitoes is largely determined by your genetics, he says.
“Those with type-o blood are about twice as attractive to mosquitoes as those with type-a, with type-b somewhere in the middle.”
Being a secretor — somebody whose saliva contains their blood-type antigens — also makes you more prone to bites: around one in five of the population are non-secretors. It is only female mosquitoes who bite us. They detect warmth and chemicals in sweat, but mainly track carbon dioxide breathed out by mammals. Your metabolic rate can therefore affect your susceptibility to mosquito bites, because if you give off high levels of carbon dioxide, they will be more drawn to you. This explains why pregnant women with higher-than-normal breathing rates are more prone to bites. Drinking alcohol and exercising can both raise resting metabolic rate.
“Your skin bacteria can have an influence,” he says. “We all have lots of different skin bacteria, but some are more attractive and repulsive to mosquitoes.
“Heat is also important, so if you’re the sort of person who tends to be running a little warmer than others, you probably attract mosquitoes a bit more.” Again this is bad news for pregnant women, who have slightly raised body temperatures.
how Do i avoid bites?
So, you’ve drawn the genetic short straw and your blood type makes you irresistible to mosquitoes. Is there anything you can do?
Dr. Nick Scriven, president of the Society for Acute Medicine, advises “loose clothing that covers your limbs” — advice also given by the U.K.’S National Health Service (NHS), which says: “If you’re outside at a time of day when insects are particularly active, such as sunrise or sunset, cover your skin wearing loose sleeves and (pants, and) wear shoes (not flip-flops) when outdoors.”
“The classic advice is covering up,” Hart says.
“Humans are large, warm and easy to spot. When it’s warm, we’re wearing shorts, T-shirts, and swimming (outfits), so we have this perfect storm of behaviour.”
A moisturizer by Avon called Skin So Soft, which contains citronella, has developed a reputation as a surprisingly effective mosquito repellent, after it was reported that the Royal Marines use it to fend off insects. Hart advises sticking to repellents with DEET, a spray-on liquid that many travellers avoid because of its unpleasant smell. Female mosquitoes bite humans because they are looking for blood to produce eggs, he says — “so they are really driven to feed on you. People think, ‘Oh, we’ll get away with it this time,’ but you probably won’t.”
There is no evidence that food or drink — such as Marmite, garlic or vitamin B supplements — will stop you getting bitten by mosquitoes.
should i avoid Dark colours?
It sounds like an old wives’ tale: don’t wear red in a hot country, as it makes us more visible to bloodsucking insects. But it’s true, Hart says: “Darker colour and reds might make you easier to spot because mosquitoes have quite good eyes.”
to scratch or not to scratch?
Disaster strikes, and you feel the telltale itch of an insect bite. Should you avoid scratching at all costs? Yes, says Scriven: “The bite causes inflammation, which causes itching. If you scratch it, it’ll make the inflammation worse. And you may break the skin. The bite is a microscopic puncture, but if you scratch and scratch it then pretty soon you’ll open the skin a lot more, and end up with secondary infections. The best advice is always the boring advice: not to scratch.”
then how Do i treat it?
Antihistamines can relieve the itchiness, says Hart, and placing an ice cube on to your bite can soothe the affected area.
He also recommends some topical antihistamine cream designed for treating insect bites and “just washing the bite with soap and water.’ ”
A number of firms have begun offering oil-based “bite ointment,” made up of lavender oil, coconut oil and beeswax. Hart says he “can’t find any studies” that test lavender oil, but says it may act as a repellent.
And don’t waste your time, the NHS warns, with tea tree oil, herbal remedies, garlic and yeast extracts or anti-mosquito buzzers — none of them work.