Abstract: Background: Molecular diagnostic tests using real-time PCR (qPCR) broaden the capacity for gastrointestinal (GI) parasite detection as compared to more traditional fecal testing. Additionally, the qPCR panel identifies genetic markers conferring anthelmintic resistance and identifies potentially zoonotic Giardia assemblages.
Objective: To determine regional and seasonal distribution of 20 intestinal parasites, benzimidazole resistance, and Giardia with zoonotic potential, from North America (NA).
Samples: Sample set consisted of 315,953 fecals submitted to a reference laboratory for KeyScreenTM GI Parasite PCR panel testing between March and December 2022.
Methods: Samples underwent nucleic acid extraction and qPCR analysis to identify 20 common GI parasites in cats and dogs, the genetic marker for A. caninum benzimidazole resistance (F167Y), and assemblage A/B Giardia duodenalis conferring zoonotic potential.
Results: The majority of submissions, 83.1% (262,641), were from dogs, with 16.9% (53,312) from cats. One or more parasites were detected in 25.4% (80,150/315,953); 26.3% (68,985/262,641) in dogs and 21.1% (11,232/53,312) in cats. Co-infections were detected in 20.5% of samples with parasites (16,431/80,150). A. caninum benzimidazole resistance frequency was 11.2% (731/6,538) of canine samples, 11.3% in the US (727/6,437), and 4.0% in Canada (4/101). G. duodenalis was detected in 13.4% of samples (42,238/315,953); 3.8% (1,610/42,238) of which belonged to the potentially zoonotic assemblages.
Conclusions and clinical importance: These data provide a parasite frequency update and emphasize the importance of routine GI parasite screening with a broad parasite panel. The presence of anthelmintic resistance and G. duodenalis assemblages with zoonotic potential highlight antimicrobial stewardship and One Health considerations.
