Molecular Markers of Pesticide Resistance and Pathogens in Human Head Lice (Phthiraptera: Pediculidae) From Rural Georgia, USA.

Although the head louse, Pediculus humanus capitis De Geer, and body louse, Pediculus humanus humanus L., both have a worldwide distribution, the occurrence of head louse pediculosis appears to be more prevalent in modern societies despite systematic use of various pediculicides. This study tested head lice collected in rural Georgia and body lice collected in Russia for the prevalence of a kdr-biomarker that is associated with permethrin resistance. This study also screened lice for the presence of DNA from Bartonella quintana and Acinetobacter species. The kdr-permethrin resistance biomarker for the T917I mutation was detected by RFLP and PCR in 99.9% of head lice tested from Georgia, whereas only 2.9% of body lice from Russia tested positive for this kdr biomarker. DNA of B. quintana was detected in 10.3% of head lice from Georgia, whereas 84.8% of body lice from Russia tested positive. Acinetobacter DNA was detected in 80.8% (95% CI, 68-89%) of head lice from Georgia and all body lice from Russia tested.