According to a team of British researchers, the bloodsucking insects are becoming resistant to DEET, the chemical found in most insect repellents whether dispensed by aerosols, liquid pump sprays or lotions.
DEET does not kill the bugs, but works as a deterrent, and scientists from the London School of Hygiene and Tropical Medicine have found that mosquitoes are getting used to the smell.
The new research indicated that the mosquitoes were initially repelled by the chemical, but went on to ignore it just a few hours later.
“What we found was the mosquitoes were no longer as sensitive to the chemical, so they weren’t picking it up as well,” researcher Dr James Logan told the British Broadcasting Corporation (BBC).
“There is something about being exposed to the chemical that first time that changes their olfactory system – changes their sense of smell – and their ability to smell DEET, which makes it less effective,” he added.
The authors of the London study, published in the journal PLOS One, said more research into alternative repellents is needed.
DEET, which was originally developed by the United States military for use in jungle warfare, was approved for use by the general public in 1957. It is now present in a variety of products under several different brand names.
While the government has repeatedly evaluated the safety of DEET, consumer anxiety has persisted to some extent over the years.
Heavy exposure can cause memory loss, headache, muscle and joint pain, and fatigue, according to some studies.
Yet DEET does not pose a health concern provided exposure is brief and consumers follow label directions, the Environmental Protection Agency (EPA) ruled in 1998.
The American Academy of Pediatrics recommends that products containing DEET should not be used on infants younger than 2 months.
Reprinted from Caribbean360