Tuesday, May 11, 2010

Yellow fever mosquito's resistance to DEET !.....

In continuation of  my update on mosquito repellents,  I found this info  interesting to share with. We know that N,N-Diethyl-meta-toluamide, DEET (see structure), is the most common active ingredient in insect repellents. It is intended to be applied to the skin or to clothing, and is primarily used to repel mosquitoes. In particular, DEET protects against tick bites, preventing several rickettsioses, tick-borne meningoencephalitis and other tick-borne diseases such as Lyme disease. It also protects against mosquito bites which can transmit dengue fever, West Nile virus, eastern equine encephalitis, and malaria. 

Now researchers from Swedish University of Agricultural Sciences (SLU) and associates in the UK, for the first time in laboratory tests have shown that yellow fever mosquito has developed a resistance to the mosquito repellent DEET.
"Through testing, we have found that yellow fever mosquitoes no long sense the smell of DEET and are thereby not repelled by it. This is because a certain type of sensory cell on the mosquito's antenna is no longer active" says Rickard Ignell, a researcher at the Division for Chemical Ecology at SLU in Alnarp....

Rickard Ignell performed the research in collaboration with Rothamstead Research in the UK. The scientists have thus seen that the sensory cell on the mosquito's antenna has stopped reacting to DEET. This have many explanations, such as the protein that binds in to DEET having mutated. The researchers are now urging restrictiveness in the use of DEET and other mosquito repellents on a large scale in a limited area, in order not to make other mosquito species resistant. The mechanism is still to be established, but in my opinion its a interesting finding....

Ref : http://www.pnas.org/content/early/2010/04/26/1001313107


6 comments:

Joerg Kurt Wegner said...

Actually, amazing, and I hate waking up in the middle of the night hunting mosquito's ... and now the repellent is not even working during the day ... poor me ;-)

Syn-chemist said...

Its nice to see you commenting after a long time. U have updated ur webpage also. Nice to see the updated page...

Bennurs said...

"Yellow fever mosquito's resistance to DEET !....." This is not known by many people hence this information is important and should be given wider publicity

Syn-chemist said...

You are right sir....

DEET is believed to work by blocking insect olfactory receptors for 1-octen-3-ol, a volatile substance that is contained in human sweat and breath..
As per the claim by the researchers,
a certain type of sensory cell on the mosquito's antenna is no longer active...

But good news is that, there are many groups working on better and cheaper mosquito repellents...
e.g.,
1.http://synchemist.blogspot.com/2009/09/discovery-of-natural-odors-new-way-to.html

Thanks for your comments.....

Joerg Kurt Wegner said...

Umesh ... I know ... in life all is about making "choices" and I had many business deadlines in the last week ;-) Besides, even listening to others is already a lot of work.

Syn-chemist said...

Yeah, Joerg I agree with you and I think it is our choices that show what we truly are, far more than our abilities... All the best for your endeavour...