04 Aug ‘Super lice’ have spread to 48 US states, study finds
A new study that suggests ‘super-lice,’ or lice that are resistant to over-the-counter medication, have become more widespread in the United States.
The research, published in the March edition of the Journal of Medical Entomology, found that lice resistant to common treatments containing pyrethroids have reached 48 U.S. states, up from an estimated 25 states reported by another group in February.
The study, which is making its media rounds now at the start of the school year, concluded that head lice collected at 138 sites across the country had a resistance aelle frequency (RAF) of 98 percent and that these lice contained a resistant trait called knockdown resistance (kdr), indicating their resistance to pyrethroids.