Knockdown resistance (kdr) Associated organochlorine Resistance in human head lice: Systematic review and meta-analysis

Introduction Pediculosis is one of the vector-borne diseases that has spread in most regions of the world and has affected many populations. In previous decades, organochlorine poisons were used to treat it. But resistance to treatment against this group of insecticides affected its control. Based on this, the present study was conducted to investigate the prevalence of Knockdown Resistance in human head lice against organochlorine insecticides in the world in the form of a systematic review and meta-analysis. Methods To determine the prevalence of Knockdown Resistance against organochlorine insecticides, all English and non-English articles (at least with English titles and abstracts) were published worldwide without a time limit until the end of May 2022 and were extracted and analyzed. Statistical analysis of the data was done using statistical tests of fixed and random effects model in the meta-analysis, Cochrane, meta-regression, and I2 index. Results 8 articles with a sample size of 7249 head lice were included in the meta-analysis process. The prevalence of knockdown resistance was estimated at 65.3%. Also, the prevalence of homozygote resistance was 71.9% and heterozygote resistance was 28.1%. Conclusion Based on the findings, more than half of the lice were resistant to organochlorine insecticides. As a result, due to the high prevalence of resistance, it is recommended to determine the resistance against them before using this group of insecticides to treat pediculosis and then adopting the appropriate treatment.