Prevalence and Molecular Characterization of <i>cytb</i> Gene of <i>Pediculus humanus capitis</i> in the Northern Regions of Basrah Province, Iraq

Human head lice are widely dispersed ectoparasites in the world and have been divided into 6 haplogroups (A to F). There are no studies about the louse haplogroup type in Iraq. Thus, the study aimed to determine the species of head lice and their prevalence rate in primary school students in north Basrah and also aimed to determine the genotype and haplogroup of head lice in these regions. All louse samples belong to Pediculus humanus capitis and their prevalence rate was significantly higher in female students (34.9%) than in male students (23.2%). Molecular genotyping of the cytb gene using PCR together with the Sanger sequencing method was employed to determine the louse haplogroups and subgroups. Based on species-specific primers, the cytb amplified size was 348 bp for all samples. The cytb sequence results for randomly selected samples showed that samples shared 99.43 to 100% identities and shared 100% identities with GenBank samples (Pediculus humanus capitis). A phylogeny showed all samples belonged to haplogroup A, and the subgroup network separated these sequences into two unique subgroups (S1 and S2). These subgroups shared 99.43% and 100% identities based on nucleotide and amino acid sequences, respectively. The current study reported that the head lice in primary school students in north Basrah belonged to Pediculus humanus capitis and their prevalence rate ranged from 23.2 to 34.9%. It was also informed for the first time in Iraq that these lice were ancestry from two unique subgroups of haplogroup A.