Evaluation of OvaCyte for the detection of gastrointestinal parasites in ovine and bovine animals: comparison with traditional flotation techniques.

Abstract

This study aimed to evaluate the diagnostic and analytical performance of OvaCyte, an automated image-based system for the detection of gastrointestinal parasites in ruminants, against traditional flotation techniques. OvaCyte is available in two versions: OvaCyte Plus, which automates egg detection and quantification, and OvaCyte Premium, which incorporates enhanced analysis to differentiate parasite families, genera, and species within strongyles (e.g., Trichostrongylidae, Haemonchus contortus, and Nematodirus spp.). Coccidia are also classified as standard or type B, with the latter specifically including Eimeria weybridgensis, Eimeria crandallis and Eimeria ovinoidalis, based on distinct morphometrical features. The identification of Haemonchus contortus was validated using peanut agglutinin (PNA) fluorescence staining as the gold standard. Sensitivity and specificity for OvaCyte Plus, Mini-FLOTAC, and McMaster were calculated based on a consensus "true status". Limits of detection and quantification were calculated using regression analysis. OvaCyte Plus demonstrated the highest sensitivity, especially for Nematodirus (95%), coccidia (93%), strongyles (92%), and Strongyloides papillosus (90%). Mini-FLOTAC showed moderate sensitivity (63-79%), while McMaster had the lowest value (30-76%). For Moniezia spp., sensitivity was similar for OvaCyte Plus and Mini-FLOTAC (79%), but lower for McMaster (59%). Specificity was high across all techniques (92-100%). Differences in performance were attributed to varying multiplication factors: OvaCyte Plus (3 EPG), Mini-FLOTAC (7.5 EPG), and McMaster (50 EPG). Strong correlations were observed between OvaCyte Plus and manual techniques for strongyle egg counts. OvaCyte Premium exhibited the highest sensitivity across all parasites. OvaCyte Plus and Premium demonstrated performance comparable to or exceeding traditional techniques for the detection of gastrointestinal parasites in ruminants.