Occurrence and molecular phylogeny of Fasciola species in camels of southwestern Iraq.

Abstract

Background and aim: Fasciola spp. are important trematodes of public health concern in various animals, including camels. This study aimed to determine the occurrence of liver flukes in camels, to determine the molecular confirmation of Fasciola, and to perform phylogenetic analysis of study isolates to identify the species of Fasciola.

Materials and methods: In total, 107 slaughtered camels were inspected to collect liver flukes that were examined molecularly using polymerase chain reaction (PCR) to confirm Fasciola species. Then, the study isolates were sequenced, submitted to the National Center for Biotechnology Information (NCBI) database, and analyzed phylogenetically to identify the species of each study isolate.

Results: Liver flukes were detected in 17.67% of the camels. Regarding the migratory stages of the collected worms, juvenile worms (73.91%) were significantly more prevalent than adult worms (26.09%). Regarding the risk factors, a significantly greater occurrence rate and risk of infection was detected in Al-Najaf compared with Al-Muthanna, as well as in younger camels (1-4 years) compared with older camels. Although the occurrence rate of liver flukes was insignificantly different between females (9.38%) and males (6.98%), females appeared to be at a significantly higher risk of infection than males. Molecularly, 33.33% of the worm samples were positive for species in the Fasciola genus. Phylogenetic analysis of all positive PCR products (total no = 19) confirmed that 63.16% of the local Fasciola spp. isolates were related to the NCBI-Basic Local Alignment Search Tool (NCBI-BLAST) Saudi Arabian Fasciola hepatica isolate at an identity range of 95.94%-99%; while 36.84% of the local Fasciola spp. isolates were related to the NCBI-BLAST Iranian F. gigantica isolate at an identity range of 97.73%-99%.

Conclusion: This study found a 17.67% occurrence of Fasciola spp. in camels, with juvenile worms being more common than adult worms. Molecular analysis revealed that 63.16% of the isolates were related to F. hepatica from Saudi Arabia, while 36.84% matched F. gigantica from Iran. Younger camels and those from Al-Najaf were at higher risk, highlighting the need for targeted control measures.