Tuesday, November 3, 2015

Why Mosquitoes Like Some People Better Than Others

Do You Smell Good to A Mosquito?
We have known for some time that mosquitoes are attracted to the CO2 we breath out. However, more recently studies have been examining the mosquitoes attraction to how we smelll. It turns out mosquitoes think some folks smell better than others.

None of us like getting bitten by mosquitoes. However, it becomes really important if you live in an area with malaria. So, researchers are trying to figure out how to make people smell bad to a mosquito.

HLA Genes
It turns out that human leukocyte antigen (HLA) genes are involved in regulation of human body odor. So, HLA genes were studied and it was discovered that those with HLA gene Cw.07 are more attractive to mosquitoes. The same research looking at the genes also looked at the scents that were associated with these people and found out that limonene, 2-phenylethanol and 2-ethyl-1-hexanol were associated with individuals that were not very attractive to the mosquitoes while  lactic acid, 2-methylbutanoic acid, tetradecanoic acid and octanal was very attractive to the mosquitoes. 

The fact that the people repelling the mosquitoes had a limonene component in their scent is no surprise since limonene containing essential oils are used as mosquito repellants. There are various research experiments showing limonene containing herbs as effective for use as  insect repellents.

The Skin Microflora Changes How Mosquitoes React to You
Now where it became really interesting to me as a person fascinated with all the bugs that live on and in our body, is the research looking at human skin microbiota and how the scent from the microflora on our skin is more or less attractive to the mosquitoes

It turns out that the people most attractive to the mosquitoes are the people with a high number of skin bacteria but lower diversity of bacteria on the skin. Those with more microbial diversity were less attractive. 

They even looked at which bacteria were more or less attractive to the mosquitoes. The mosquitoes seemed to like the smell of Staphylococcus epidermidis. People with a higher amount of Pseudomonas spp. or Variovorax spp. and had greater overall diversity were less attractive to mosquitoes.

This means in the not so distant future, you might be spraying bacteria over your skin when in a mosquito infested area. There is already bacteria skin (Nitrosomonas eutropha) spray that is being used to decrease body odor. Soon, there will be one to repel mosquitoes.