Comparative Accuracy of Fecal Sedimentation, Fluke Finder, and Coproantigen ELISA for Diagnosing Fasciola hepatica in Sheep

Fasciola hepatica is the primary helminth in the Fasciolidae family responsible for causing zoonotic fascioliasis worldwide. This study aims to investigate the occurrence of Fasciola hepatica infection (FHI) in sheep of different ages, sexes, breeds, and management practices. Additionally, the sensitivity, specificity, and accuracy of fecal sedimentation methods (SS) and Fluke Finder (FF) instruments were compared to recently developed commercial kits, specifically the coproantigen enzyme-linked immunosorbent assay (C Ag ELISA). A total of 92 fecal samples were collected from animals naturally infected with FH (46 ewes and 46 rams) across various districts of Mosul, Iraq. FHI prevalence was 15.2% (CI = 8.3–25.5) with SS, 16.3% (CI = 9.1–26.9) with FF, and 20.6% (CI = 12.4–32.3) with C Ag ELISA. When C Ag ELISA served as the gold standard, both SS and FF showed high accuracy—94.6% for SS, 95.7% for FF, with a Kappa value (κ) of 0.877. Although the sensitivities were 73.7% and 78.95% respectively, outdoor feeding was the strongest variable associated with FHI (Odds ratio (OR) 3.2; 95% CI: 19.9 to 56.5, P = .01), followed by age of 3-5 years (OR 3.1; 95% CI: 17.6 to 50.0, P = .02). Despite management efforts and medication, FHI continues to impact the study area. Both SS and FF proved accurate and demonstrated high agreement; however, they detected only 75% of infected animals. Sheep aged 3–5 years that grazed outdoors showed significantly higher infection rates.