Evaluation of resistance of human head lice to pyrethroid insecticides: a meta-analysis study

Abstract

AbstractIntroductionPediculosis is one of the most common annoying infections caused by insects in humans. Pyrethroids are one of the main insecticides used to treat this infection. But recently, due to the resistance of lice to this group of insecticides, its therapeutic effects have been affected. Based on this, the present study was conducted to investigating the prevalence of resistance to treatment against these insecticides in the world in the form of a meta-analysis.MethodsThis study was conducted as a meta-analysis on the prevalence of treatment resistance in human head lice against pyrethroid insecticides in the world. Based on this, all articles published without a time limit until the end of June 2022 in PubMed/MEDLINE, Web of Science (ISI), Scopus, and Google Scholar databases were extracted and using random effects model statistical methods in the meta-analysis, Cochrane, Index I2 and funnel plot were analyzed by STATA software.ResultsTwenty studies were included in the meta-analysis process. According to this the prevalence of resistance to pyrethroid insecticides in human head lice was estimated at 59% (CI95%: 50% to 68%). Among pyrethroid insecticides, the highest prevalence of resistance to treatment against permethrin insecticide was 65%. Regarding the prevalence of resistance by year, the prevalence before 2004 was estimated at 33%, but after 2015, this rate reached 82%. Also, the prevalence of resistance to treatment was estimated at 68% using genetic diagnosis methods and 43% using clinical diagnosis methods.ConclusionMore than half of human head lice are resistant to pyrethroid insecticides. Based on this, it is recommended that before using this treatment method to treat human head lice infestation, the prevalence of resistance to treatment in that area should be investigated and if the prevalence of resistance is high, alternative or combined treatment methods should be used.