Bed bugs: clinical relevance and control options.

the common bed bug, Cimex lectularius

Bed bugs: clinical relevance and control options.
Clin Microbiol Rev. 2012 Jan;25(1):164-92.
http://www.ncbi.nlm.nih.gov/pubmed/22232375
Doggett SL, Dwyer DE, Peñas PF, Russell RC.

Department of Medical Entomology, ICPMR, Westmead Hospital, Westmead, New South Wales, Australia

the species Cimex lectularius and Cimex hemipterus

Cutaneous reactions may occur and can start out as small macular lesions that can develop into distinctive wheals of around 5 cm in diameter, which are accompanied by intense itching.
Occasionally, bullous eruptions may result. If bed bugs are numerous, the patient can present with widespread urticaria or eythematous rashes.

there is no definitive evidence that they transmit any disease-causing organisms to humans.
Anemia may result when bed bugs are numerous, and their allergens can trigger asthmatic reactions.

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Chemistry Research Roundup
September 13, 2013
http://www.npr.org/2013/09/13/222101245/chemistry-research-roundup

researchers at the University of Kentucky have identified the genes in the bug’s shell and use them as targets for attacking the bugs. Susan Jones is a professor of entomology at Ohio State University in Columbus.

we had found data suggesting that a lot of the genes that were involved in resistance were highly expressed in the insect cuticles.
… the insect cuticle is a site of very highly expressed gene activity.

there are a lot of different resistance mechanisms that are being employed and being expressed in the bed bug skin or cuticle.
And some of these are involved in metabolic resistance.
There are others that are involved in target site resistance.
And then others that are involved in other mechanisms as well including the penetration resistance.

one way of looking at it is that they have different enzymes and different mechanisms where they are actually able to degrade and biochemically change the insecticide.
So they can then excrete it from the outside of the body without it ever being able to reach the target site, which is going to be the insect nerve system.

the pyrethroids are affecting what we call the voltage gated sodium channels in the membrane of the nerve.

years ago when we brought – had DDT on the market, it was a chlorinated hydrocarbon, so a different class of chemistry.
But it basically worked the exact same way as pyrethroids work.
And so what this means is because of bed bugs throughout the world being exposed to chlorinated hydrocarbons, we have a condition that’s called cross resistance.

These little bugs can go from egg, through five immature stages, to reach the adult stage in as quickly as three weeks time.
If it’s a little – and that’s at temperatures that are fairly warm, 85 degrees.
But if you decrease the temperature to about 65 degrees, they still are going to complete that lifecycle and become reproductive adults in only three months time.

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video:
http://www.shutterstock.com/video/clip-5134313-stock-footage-bedbug-sitting-on-human-skin.html

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