Mosquito repellant lasted 73 days; (study)

[Gert van der Hoek]

Bug repellant lasted 73 days in Fla. study



Bloomberg News / May 27, 2008

SINGAPORE - An experimental mosquito repellant deterred the blood-sucking insects for as long as 73 days, more than four times longer than marketed products, in a study that may help prevent diseases such as malaria and dengue fever.

Scientists at the University of Florida tested 34 repellants on two volunteers in a laboratory who wore the chemicals on cloth patches stuck to a glove, which they inserted into a box containing about 500 insects for one minute.

One chemical warded off the bugs for 73 days, compared with 17 1/2 days for the chemical DEET, which has been used as a repellant for 50 years, the authors wrote in the Proceedings of the National Academy of Sciences.

If commercialized, the research may help health officials around the world stem the spread of mosquito-borne diseases, which sicken more than 550 million people each year, according to the World Health Organization.

Global warming will put millions more at risk, as increases in rainfall, temperature, and humidity enable disease-spreading mosquitoes to breed to higher altitudes, the United Nations said in a November report.

http://www.boston.com/business/articles/2008/05/27/bug_repellant_lasted_73_days_in_fla_study/

 

[Gert van der Hoek]

Re: Mosquito repellant lasted 73 days; (study)

May 27, 2008

New Repellents Without DEET Show Promise in Tests on Humans

By DONALD G. McNEIL Jr.

Researchers have found several new mosquito repellents that appear to work more than three times as long as DEET.

DEET ? or N,N-diethyl-m-toluamide ? has been used for 50 years and is still the gold standard. But new repellents are always needed because the threat from mosquito-borne diseases like malaria, yellow fever, West Nile virus and Rift Valley fever is growing.

Chemists at the University of Florida and the United States Department of Agriculture screened many acylpiperidines, which are related to the active ingredient in pepper.

Their study was published online Monday in The Proceedings of the National Academy of Sciences.

In tests on humans, they found that some acylpiperidines could repel mosquitoes for up to 73 days, while DEET typically lasted only 17 days.

However, the tests did not replicate typical exposures. Volunteers wore thick gloves with holes, over which were taped pieces of muslin soaked in repellent, and their arms were thrust into cages of mosquitoes for only one minute.

?Failure to repel? was recorded on the first day that five mosquitoes bit through the cloth.

Tests of commercial repellents in 2002 done with bare skin found that the most effective were those that contained the most DEET ? and they lasted only about five hours.

Further tests will be needed to see whether the acylpiperidines irritate skin, evaporate, dissolve in sweat or fail in ways that other repellents do.

http://www.nytimes.com/2008/05/27/health/research/27glob.html?_r=1&oref=slogin&pagewanted=print

 

[tropical]

Re: Mosquito repellant lasted 73 days; (study)

We must cautioned new sprayings.

One day I sprayed an commercialized ordinary human-skin bug repellent on the final part of an rose plant carrying many green bugs (plant limpha sucking bugs).

The next day I found that all the rose necrotized, from the roses to the root.