Transmission Patterns of Zoonotic and Emerging Pathogens in Canada's North Related to Climate Change

Abstract

Country food is a term used to describe the traditional food of the Northern Canadian Indigenous population. Country food diets are of great cultural significance but lead to increased risks of contracting zoonotic pathogens as most preparations of meat and fish are uncooked.

Climate change could lead to northward migration or range extension of certain animals, which could result in increased risk of zoonotic transmission in Northern Canada. Hepatitis E virus (HEV) is a zoonotic pathogen that can transmit through the consumption of uncooked meats and causes acute and chronic hepatitis in humans. Toxoplasma gondii (T. gondii) is a protozoan parasite that causes zoonotic toxoplasmosis in humans. Toxoplasma gondii has been observed in Northern Canadian wildlife and can also transmit through the consumption of uncooked meats. This study aims to examine the prevalence of HEV and T. gondii in wildlife harvested as country food in relation to climate change.

Caribou, ringed seal and beluga are some of the keystone country food species that were sampled from various Northern Canadian regions. Prevalence was measured using PCR to detect pathogen genomes in serum, blood and tissues. Serological testing was performed using enzyme-linked immunosorbent assays (ELISA) for detection of antibodies against HEV and T. gondii.

These methods were successful in detecting both HEV and T. gondii in country food samples at higher prevalence than previously reported. There was also detection of HEV in ringed seal (Pusa hispida) and beluga (Delphinapterus leucas) which is the first time that HEV has been detected in these species. These results suggest that there is a potential food safety risk to humans when consuming country foods in Canada's North. These findings may explain the high seroprevalence of T. gondii in humans in these regions.