Low prevalence of zoonotic food-borne parasites Toxoplasma gondii and Trichinella spp., but high prevalence of a potential marine Sarcocystis spp., in Eastern Beaufort Sea beluga whales (Delphinapterus leucas) harvested in the Canadian Arctic

Abstract

Beluga whales (Delphinapterus leucas (Pallas, 1776)) are traditional food sources for Inuit communities in the Canadian Arctic. In response to community concerns about zoonotic parasites (Toxoplasma gondii and Trichinella spp.), the aim of this study was for harvesters, government, and researchers to jointly determine prevalence of selected parasites in belugas harvested from the Eastern Beaufort Sea population between 2014 and 2021. We used multiple molecular and serological assays to detect Toxoplasma gondii in the absence of gold standards. Antibodies against Toxoplasma gondii were detected in less than 1% (n = 1/120) of belugas using multiple commercial and in-house serological tests. Based on multiple molecular assays, Toxoplasma gondii DNA was detected in 1% (n = 1/97) of belugas. Trichinella larvae were not detected in diaphragms (n = 42) or tongues (n = 108) by the internationally recognized pepsin/HCl artificial digestion method. Sarcocysts were observed on histology in 6/26 beluga examined in 2015–2016 and DNA of an unidentified species of Sarcocystis sp. was detected in skeletal muscle of 59% (n = 46/78) of belugas. Phylogenetic analyses indicate a close relationship between the Sarcocystis found in belugas and those from other marine mammals, suggestive of a marine life cycle requiring further investigation. Our findings reflect a low prevalence of Toxoplasma gondii and Trichinella spp., and therefore low risk of human exposure to these parasites through the consumption of belugas from the Eastern Beaufort Sea.

Keywords

• Toxoplasma
• Sarcocystis
• Trichinella
• Beluga
• whale