Parasitology

Research Article

Spatio-temporal variations and age effect on Toxoplasma gondii seroprevalence in seals from the Canadian Arctic

A. SIMONa1 c1, M. CHAMBELLANTa2a3, B. J. WARDa4, M. SIMARDa5, J. F. PROULXa6, B. LEVESQUEa7a8, M. BIGRAS-POULINa1, A. N. ROUSSEAUa9 and N. H. OGDENa10

a1 Faculté de médecine vétérinaire, Université de Montréal, Pathologie et microbiologie Saint-Hyacinthe, Québec, Canada

a2 Fisheries and Oceans Canada, Fisheries and Oceans, Winnipeg, Manitoba, Canada

a3 University of Manitoba, Department of Biological Sciences, Winnipeg, Manitoba, Canada

a4 Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, Quebec, Canada

a5 Makivik Corporation, Nunavik Research Center, Kuujjuaq, Quebec, Canada

a6 Nunavik Regional Board of Health and Social Services, Direction de la Santé Publique, Kuujjuaq, Quebec, Canada

a7 Centre de Recherche du Centre Hospitalier Universitaire de Québec, Axe Santé des Populations et Environnement, Québec, Québec, Canada

a8 Institut National de Santé Publique du Québec, Direction de la Santé Environnementale et de la Toxicologie, Québec, Québec, Canada

a9 Institut National de Recherche Scientifique, Centre Eau Terre Environnement, Québec, Québec, Canada

a10 Zoonoses Division, Centre for Food-borne, Environmental and Zoonotic Infectious Diseases, Public Health Agency of Canada, Saint-Hyacinthe, Quebec, Canada

SUMMARY

Toxoplasmosis is a significant public health threat for Inuit in the Canadian Arctic. This study aimed to investigate arctic seals as a possible food-borne source of infection. Blood samples collected from 828 seals in 7 Canadian Arctic communities from 1999 to 2006 were tested for Toxoplasma gondii antibodies using a direct agglutination test. Polymerase chain reaction (PCR) was used to detect T. gondii DNA in tissues of a subsample of seals. Associations between seal age, sex, species, diet, community and year of capture, and serological test results were investigated by logistic regression. Overall seroprevalence was 10·4% (86/828). All tissues tested were negative by PCR. In ringed seals, seroprevalence was significantly higher in juveniles than in adults (odds ratio=2·44). Overall, seroprevalence varied amongst communities (P=0·0119) and by capture year (P=0·0001). Our study supports the hypothesis that consumption of raw seal meat is a significant source of infection for Inuit. This work raises many questions about the mechanism of transfer of this terrestrial parasite to the marine environment, the preponderance of infection in younger animals and the natural course of infection in seals. Further studies to address these questions are essential to fully understand the health risks for Inuit communities.

(Received April 28 2011)

(Revised June 13 2011)

(Accepted June 22 2011)

(Online publication August 04 2011)

Correspondence:

c1 Corresponding author: Groupe de recherche en épidémiologie des zoonoses et santé publique, Faculté de médecine vétérinaire, Université de Montréal, 3200 Sicotte, C.P. 5000, Saint-Hyacinthe, J2S 7C6, Québec, Canada. Tel: +1(450) 773 8521 ext. 0082. Fax: +1(450) 778 8129. E-mail: audrey.simon@umontreal.ca

Metrics