Head Lice: New Mutation In 25 States Resistant To Medication

Last week, a finding was presented on head lice at the 250th National Meeting and Exposition of the American Chemical Society. In the presentation, health scientists detailed how a particular mutated strand of head lice had made its way into 25 states in America.

Dr. Kyong Yoon said at the conference that the strain of head lice is extremely resistant to over-the-counter medications.

“We are the first group to collect lice samples from a large number of populations across the U.S. What we found was that 104 out of the 109 lice populations we tested had high levels of gene mutations, which have been linked to resistance to pyrethroids.”

The pyrethroids are what are commonly used in indoor and outdoor pesticides. Permethrin, a type of pyrethroid, is the most active ingredient in the most commonly sold lice treatments.

Dr. Yoon said that pyrthroid-resistant lice has been growing and mutating for several years, with the first strains of drug-resistant lice being discovered in Israel in the 1990s. Dr. Yoon discovered the first American case of the drug-resistant lice in 2000 when he was doing undergraduate work at the University of Massachusetts in Amherst.

“I was working on insecticide metabolism in a potato beetle when my mentor, John Clark, suggested I look into the resurgence of head lice. I asked him in what country and was surprised when he said the U.S.”

Dr. Yoon started collecting head lice samples from neighboring schools and soon discovered the drug-resistant head lice.

After several years of study, Dr. Yoon came to the conclusion that a combination of various chemicals, which are often prescribed to treat head lice, can actually work against its spread.

“If you use a chemical over and over, these little creatures will eventually develop resistance. So we have to think before we use a treatment. The good news is head lice doesn’t carry disease. They’re more a nuisance than anything else.”

There is no real preventative for head lice. Given the often close proximity of their heads while playing, head lice is most prominent in children. Lice being able to “jump” or “hop,” however, is a myth, as the most the worm-like insects can do is crawl. Daily baths are not a real preventative, since head lice can survive submerged in water for up to 20 minutes. Furthermore, the eggs of lice, which glue themselves to shafts of hair very close to the scalp, are often immune to any and all chemicals.

The American Academy of Pediatrics suggests that the best way to stop the spread of lice is for parents to be vigilant, detecting and inspecting their children regular for infestation. Once found, the early treatment of head lice prevents the spread of the insects to others.

[Photo by Matt Cardy/Getty Images]