Tehran University of Medical Sciences Iranian Journal of Public Health 2251-6085 51 8 2022 08 11 1847 1856 Peyman Heydarian Department of Medical Parasitology and Mycology, School of Medicine, Qazvin University of Medical Sciences, Qazvin, Iran Vahid Jajarmi Department of Biotechnology, School of Advanced Technologies in Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran 2. Cellular and Molecular Biology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran Adel Spotin Infectious and Tropical Disease Research Center, Tabriz University of Medical Sciences, Tabriz, Iran Keyhan Ashrafi Department of Medical Parasitology and Mycology, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran Mehdi Mohebali Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran Mojgan Aryaeipour Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran Arezoo Bozorgomid Infectious Diseases Research Center, Health Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran Elham Hajialilo Department of Medical Parasitology and Mycology, School of Medicine, Qazvin University of Medical Sciences, Qazvin, Iran Mohammad Javad Abbaszadeh Afshar Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran Mandana Fadaei Tehrani Department of Medical Parasitology and Mycology, School of Medicine, Jiroft University of Medical Sciences, Jiroft, Iran Mohammad Bagher Rokni Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran 2022 08 11 Background: We aimed to detect the genetic diversity of samples identified morphologically as Fasciola spp. from sheep, cattle and goat from Lorestan Province, western Iran using PCR-RFLP method. Besides, we evaluated the genetic diversity indices, sequencing and phylogenetic analysis using mitochondrial gene (ND1 and CO1). Methods: PCR-RFLP analysis of ribosomal ITS1 fragment by RsaI restriction enzyme to investigate the genetic characteristics of Fasciola species obtained from different hosts (18 sheep, 21 cattle, and 17goats) was conducted.  The samples were sequenced. Sequences were evaluated using BLAST software and the parasite species were identified with similarity percentage and overlap with the species registered in the gene bank. Then similarity and diversity of intra-species and intra-species diversity of Fasciola species were calculated. Results: In Lorestan, based on RFLP pattern, 93% (52) of the Fasciola spp. isolates had a RFLP pattern related to F. hepatica and 7% (4) were F. gigantica. No hybrid forms were detected. The CO1 gene could clarify 19 haplotypes against ND1 gene that found 22 haplotypes among livestock. Sequencing results of the mtDNA showed intra-species identity 98. 5%-100% and Intra-species-diversity: 0-1.5% compared to the GenBank sequences. Conclusion: Using PCR-RFLP method, two species of F. hepatica and F. gigantica, were present in Lorestan Province, but F. hepatica was more prevalent. Mitochondrial genes could better test variability indices in different hosts than ribosomal genes, consequently among mitochondrial genes, the ND1 gene could better examine differences and similarities than CO1.  https://ijph.tums.ac.ir/index.php/ijph/article/view/29538 https://ijph.tums.ac.ir/index.php/ijph/article/download/29538/7691