Hospitalization for trichinellosis and echinococcosis in Canada, 2001-2005: the tip of the iceberg?

OBJECTIVES This study was undertaken to measure the incidence of echinococcosis and trichinellosis hospitalization in Canada, and to compare these incidence rates between residents of northern regions and the rest of the Canadian population. METHODS Cases hospitalized in 2001-2005 for either echinococcosis or trichinellosis were retrieved from the hospital morbidity database (HMDB) held by the Canadian Institute for Health Information. Crude and standardized incidence rates were calculated by province and by latitude range. RESULTS A total of 108 echinococcosis and 14 trichinellosis hospitalizations were found, yielding incidence rates of 0.72 and 0.09 per million per year, respectively. There was a clear south-north gradient in the incidence of echinococcosis hospitalization, the highest incidence (2.9 per million per year) being found north of the 55th parallel. The risk of echinococcosis hospitalization was also significantly higher in women than in men (RR 1.92, 95% CI 1.29-2.87). For trichinellosis, the highest incidence (42 per million per year) was found in Nunavut and Northern Quebec. CONCLUSION Incidence of hospitalization for echinococcosis and trichinellosis is low at the national level. However, significantly higher rates have been measured in northern regions of Canada despite the fact that both diseases are theoretically preventable and that a Trichinella control program is in place in Nunavik. Further efforts, probably educational in nature, will be required to reduce the incidence of these infections in high-risk areas.