If you witness a re-emergence of lice across the U.S., that is because populations in 25 states have developed resistance to commonly used insecticides.
A new study presented at the National Meeting and Exposition of the American Chemical Society on August 18th captured and analyzed 109 populations of lice from all over the United States.
Typically, there are a number of products for both human use and to spray around and in households that combat the appearance of lice, as well as mosquitoes and other pesky insects. These are sold over the counter, without any prescription needed. Nonetheless, they are recommended in schools where the risk of lice jumping from one child to another is high, as they are recommended by doctors.
Things are about to change with the new finding stemming from Ph.D. Kyong Yoon research. Of the 109 lice population collected from 30 different states, 104 were found to have genetically mutated to resist the common substances used to deter them.
These are known as pyrethroids and are commonly used in insecticides across the U.S. The genetical mutations with the lice have been occurring over decades. As the heavy-use insecticides were switched to lighter ones such as pyrethroids, the lice were highly susceptible to their use.
Now, tested for the ‘knock-down-resistance’ mutations or kdr, Yoon discovered that the vast majority of the lice populations collected presented all three types of mutations. Lice have developed a super-resistant nervous system, not susceptible to the use of pyrethroids.
Kdr mutations were found in lice populations from 25 states of the 30 where the samples were collected. In Florida, Texas, Maine and California, the lice populations presented all three krd genetic mutations.
In Oregon, New York, New Jersey and New Mexico, the lice were still highly resistant to the insecticides, although they presented less genetic mutations. The lice population of Michigan was the most susceptible to over-the-counter pyrethroid-containing substances.
Still, there aren’t many options to deal with the re-emergence of lice populations across the U.S. The research team suggests developing new substances and products that can effectively fight the surge of lice populations.
However, that also comes with a precautionary disclaimer. Using a new substance for too long might lead to the same type of mutations as in this present case.
Photo Credits: ctvnews.ca