James Logan's malaria myth busters

James Logan is a lecturer in medical entomology at the London School of Hygiene & Tropical Medicine (LSHTM). Any views expressed are his own. World Mosquito Day is celebrated by LSHTM on August 20 to mark Ross's discovery at the Ross Institute on Aug. 20, 1931. The institute was absorbed into LSHTM in 1934.

It is often said that certain foods make you repellent to mosquitoes such as vitamins (like vitamin
B12), marmite (which contains vitamin B12), alcohol and garlic.

Although you can often smell it yourself if you have eaten garlic, no studies have shown that it repels mosquitoes.

Things that do not work (i.e. there is no real scientific evidence to back it up):

• Garlic – might repel other people but not mosquitoes!
• Brewer’s yeast tablets
• Vitamins
• Marmite
• Guinness
• Electronic devices and high pitched sounds
• Perfume

Things that do work

There are two most important measures – especially if people are travelling to tropical countries:

1. Insect repellents (always follow the labels)
2. Mosquito nets – they are more effective if also treated with an insecticide

Other things you can do

• Wear loose clothing and long sleeves/trousers. Mosquitoes will even bite through jeans!
• Many mosquitoes bite at dawn and dusk so avoid going outdoors at these times if you can!
• Air movement like a fan or air conditioning can help a little as mosquitoes don’t like flying in strong wind
• Get rid of any pots containing standing water – this is a breeding haven for mosquitoes

Why do some people never seem to get bitten?

Mosquitoes are attracted to the scent of some people more than others because everybody’s body odours are different!

Around 15 percent of the population claim to be rarely bitten by mosquitoes.

Scientists at LSHTM, Rothamsted and Aberdeen University have shown that this is because those lucky people are producing natural repellents in their body odour – almost as if the body has a natural defence against mosquitoes. These natural chemicals are now being developed as a repellent product.

That doesn’t mean that they shouldn’t use a repellent though, as one bite from an infected mosquito is enough to pick up a disease.

Why do I react more than others to bites?

Mosquitoes are crafty!

When mosquitoes bite they inject their saliva into your body. The saliva contains a cocktail of chemicals which stops the blood from clotting and stops you from feeling pain!

Your body reacts to the saliva and this often creates itchy red lumps. Over time, if bitten a lot, certain people can become less sensitive to the bites.

For more about World Mosquito Day visit YouTrust