Molecular characterization and genetic diversity of ectoparasite <i>Pediculus humanus</i> (head lice) in Mosul city

Head lice (Pediculus humanus capitis) are among the most common parasites infecting school-age children worldwide, including in Iraq. Despite their medical and social importance, molecular data on genetic variation among head lice populations in Mosul are scarce. The present study aimed to explore the molecular characteristics and potential genetic diversity of the head louse parasite, as analyzed from samples collected from children in Mosul, Iraq. The focus of this study was on 65 head lice specimens gathered from 6- to 13-year-old children in certain areas of Mosul, Iraq, between December 2024 and March 2025. The molecular analysis utilized the Internal Transcribed Spacer (ITS) region of DNA and the polymerase chain reaction (PCR) technique. Based on the evidence, the isolates appeared to differ in strains of the human head louse, Pediculus humanus. The molecular data were submitted for further investigation to the National Centre for Biotechnology Information (NCBI) database. Six of them were newly identified isolates designated MG73, with accession code OQ319012.1. Those isolated sequences completely matched already stored sequences in the NCBI database. Additional scrutiny of the genetically based divergence among isolated strains revealed that all isolates could be primarily grouped into a single, fundamental core cluster. These results support the findings of the molecular identification and cross-sampling, which confirm the assertion of the close relationship between the strains. The observed genetic uniformity is indicative of diverse and thorough scientific attempts directed toward a single hypothesis, drawing conclusions grounded in different approaches.