High prevalence of gastrointestinal parasites in dogs from Saipan, Northern Mariana Islands, including the zoonotic Ancylostoma ceylanicum

Background

Gastrointestinal (GI) parasites of dogs, including helminths and protozoans, are of substantial relevance to veterinary medicine and public health. Nevertheless, epidemiological data are scarce worldwide, especially in remote locations. The emergence of novel technologies and diagnostic platforms facilitates comprehensive screening of multiple GI parasites. Our study aims to establish a baseline prevalence for GI parasites in dogs from Saipan, Northern Mariana Islands.

Methods

Fecal samples were collected from dogs ( n  = 420) from May to June 2023 during a spay-neuter campaign. Age, sex, ownership status, and residing location were recorded. Following genomic extraction, samples were screened using the KeyScreen™ GI Parasite PCR (Antech Diagnostics), a real-time PCR panel that detects 20 endoparasite infections, detects benzimidazole resistance in Ancylostoma caninum , and determines the zoonotic potential of Giardia duodenalis . If inconclusive results for Ancylostoma spp. were obtained, conventional PCR and Sanger sequencing were performed, targeting the ITS-1 region for species identification. Additionally, demographics (i.e. age, sex, ownership, and residing location) were evaluated as potential risk factors for each pathogen as the outcome with an initial univariate analysis, followed by multivariable logistic regression with backward stepwise selection.

Results

Overall, parasites were detected in 267/420 (63.5%; 95% CI: 58.7–68.1) canine samples. The most detected parasite genus was Ancylostoma spp. ( n  = 224; 53.3%), followed by G. duodenalis ( n  = 67; 15.9%), Trichuris ( n  = 39; 9.2%), Dipylidium ( n  = 25; 5.9%), Toxocara ( n  = 15; 3.5%), Cystoisospora ( n  = 10; 2.3%), and Cryptosporidium ( n  = 5; 1.1%). Assemblages with zoonotic potential of G. duodenalis and the SNPs 167Y and 134H in the isotype 1 Beta-tubulin gene associated with benzimidazole-resistance in A. caninum were not detected. Risk factors significantly associated with infection were age, district, and ownership with Trichuris ; age and ownership with Ancylostoma , Giardia , and Dipylidium ; and ownership with Toxocara and Cystoisospora . Hookworm-positive samples were further characterized to species level. Overall, Ancylostoma caninum and A. ceylanicum / A. duodenale were confirmed in 196 (46.7%) and 57 (13.5%) dogs, respectively. Further sequencing confirmed the presence of zoonotic A. ceylanicum in at least 21 samples, approximately 5% of the sampled dog population, distributed geographically across all districts.

Conclusions

To our knowledge, our study is the first to provide epidemiological data on canine gastrointestinal parasites in Saipan. The high prevalence of multiple parasites of One Health importance reinforces the need for surveillance and the implementation of prevention and control strategies island-wide, especially targeting A. ceylanicum , a zoonotic hookworm, that may establish patent infections in both companion animals and humans.

Graphical Abstract