Molecular analysis reveals expansion of Fasciola hepatica distribution from Afghanistan to China.

Recently, phosphoenol pyruvate carboxykinase (pepck) and DNA polymerase delta (pold) were established as reliable nuclear markers for species identification of Fasciola spp. in multiplex polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism-based assays, respectively. Currently, little is known about Fasciola species distribution in Central Asia. Therefore, the objective of the present study was to perform precise molecular species identification of liver flukes from Afghanistan and to reveal their dispersal route(s) via phylogenetic analysis based on mitochondrial nad1 haplotypes. Ninety-two Fasciolaflukes collected from sheep in Kabul, Afghanistan, were identified as F. hepatica based on pepck and pold screening. Although the pepck fragment pattern obtained via multiplex PCR analysis could not distinguish the species of the seven Fasciola flukes, the pepck nucleotide sequence data confirmed that they were F. hepatica.The 20 nad1 haplotypes detected among the Afghani liver flukes were closely related to those from China and Egypt, with the FSTvalue (-0.003, P = .41) between the F. hepatica populations from Afghanistan and China confirming a very close relationship. Nucleotide diversity was greater in the population from Afghanistan compared with that from China, indicating that the Afghani population was older, and that the dispersal direction of F. hepatica was from Afghanistan to China. The results of the present study contribute to our understanding of the dispersal of F. hepatica from its predicted origin, the Fertile Crescent.