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Mosquito Advisory

Mosquito Advisory

The Florida Department of Health has issued a statewide mosquito advisory.  In the past two months there has been an increasing number of malaria cases in the state.  Malaria is transmitted by infected Anopheles mosquitos.  The Florida cases have all been due to these mosquitos transmitting Plasmodium vivax.  So far, there have been no deaths but several people required hospitalization. 

The health department recommends reducing the chance for bites by wearing long pants and sleeves and using repellant (either on skin or on clothing) especially at dawn and dusk when mosquitos are most active.  They also recommend “cover and drain” measures to eliminate standing water where mosquitos breed:  garbage cans, house gutters, buckets, pool covers, flowerpots and plastic children’s pools. 

The symptoms of malaria include; fever, chills, sweats, nausea, vomiting and headache and should prompt individuals to seek immediate medical treatment. 

Catnip and Mosquitoes

Catnip and Mosquitoes

Neuroscientists at Northwestern University have made an amazing discovery about catnip, it repels mosquitoes and other insects.  The active component of catnip (Nepeta catoria) is nepetalactone which stimulates a neuroreceptor called TRPA1.  TRPA1 is found in most animals from insects to humans, and transmits pain sensation to the brain.  TRPA1 can also be triggered by hot, cold, and irritants. 

The interesting thing is that when applied to humans as a repellant it does not trigger a pain response in the human, nor does it trigger pain in felines.  In felines it triggers a different receptor involved in pleasure sensation. 

Work is underway to find an effective way to use nepetalactone in an easily applied skin vehicle to provide a non-DEET alternative for summer misery.

Mosquito repellant works well, but…

Mosquito repellant works well, but…

The frequent rains this summer have led to a bumper crop of hungry mosquitoes. Although many repellants are available, the most effective compound seems to be DEET. It works because its scent is extremely irritating to biting insects, such as mosquitoes and fleas.  Unfortunately, DEET is fairly allergenic with upwards of 30 percent of individuals developing a rash after repeated use. The types of rash seen are contact dermatitis (looks like poison ivy), eczema and urticaria (hives). The fact that DEET is a somewhat irritating chemical, and that it is repeatedly applied to the same skin areas, leads to the development of allergy.
Luckily, a new effective repellant has recently been developed – picordin. It, too, works because its scent dissuades biting insects; however, unlike DEET, it is not irritating or allergenic to the skin. Also, it is tolerated even in individuals already allergic to DEET.