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Smell of infected people attracts more anophelines

July 1, 2014 - 11:13 -- William Jobin

We are all aware of the Stinky Feet effect, in which human skin odors attract female anophelines in a dark bedroom. And to many of us, this suggests that we should wash our feet before going to bed.

Now, Mescher of ETH Zurich, De Moraes and others - in a recent article in Proc. of the National Academy - indicated that mice infected with Plasmodia are more attractive to anophelines than ordinary mice. SO

If this evolved as a durable trait in anopheline mosquitoes, it means it conferred either a survival advantage, or a reproductive advantage to the mosquito.

1. It is hard to see how it would give females a survival advantage to pick up an infection, but

2. It might easily give a reproductive advantage because it means the female mosquito has an extra signal to help her locate her bloodmeal in this dark room, and thus would lay eggs more often than females which could not find a meal.

It would be interesting to determine whether nightly washing of our feet would also take away the female mosquitoes advantage, and cause her to go hungry. Could foot-washing be as useful as a bednet?

And maybe a slight perfume made of neem tree oil or eucalyptus oil would be the clincher. Perfume instead of a repellent, because perfumes are attractive for people, although maybe repellent for mosquitoes. You never know!

Bill - an engineer

Comments

Bart G.J. Knols's picture
Submitted by Bart G.J. Knols on

Dear Bill,

Let me provide some more info on this matter. First, African anophelines are sensitive to extremely low concentrations of fatty acids from foot odour - thus, washing will not reduce the number of bites. In fact, these same odours are also produced on other parts of the body...

The study just published on additional attractiveness of gametocyte carrying hosts is not new and has in fact been done in humans and was published back in 2005 (http://www.ncbi.nlm.nih.gov/pubmed/16076240).

The risk of picking up gametocytes is higher when feeding on children than on adults, so gambiae has developed a tendency to prefer biting adults. The parasite obviously needs a 'taxi', so tries to enhance the attractiveness of gametocyte carriers. It's an evolutionary war...

But washing of feet is, unfortunately, not going to help us much...

Bart