Surveillance for Lyme disease in Canada, 2009-2019

Salima Gasmi; Jules K Koffi; Mark P Nelder; Curtis Russell; Scott Graham-Derham; Lisa Lachance; Bijay Adhikari; Jacqueline Badcock; Shamara Baidoobonso; Beverly A Billard; Beth Halfyard; Stéphanie Jodoin; Mayank Singal; Annie-Claude Bourgeois

doi:10.14745/ccdr.v48i05a05

Surveillance for Lyme disease in Canada, 2009-2019

Can Commun Dis Rep. 2022 May 5;48(5):219-227. doi: 10.14745/ccdr.v48i05a05.

Authors

Affiliations

¹ Centre for Food-borne, Environmental and Zoonotic Infectious Diseases, Public Health Agency of Canada, Saint-Hyacinthe, QC.
² Enteric, Zoonotic and Vector-Borne Diseases, Public Health Ontario, Toronto, ON.
³ Communicable Disease Control Branch, Manitoba Health and Seniors Care, Winnipeg, MB.
⁴ Health and Wellness Promotion Branch, Public Health and Compliance Division, Alberta Health, Edmonton, AB.
⁵ Population Health Branch, Ministry of Health, Regina, SK.
⁶ Office of the Chief Medical Officer of Health, New Brunswick Department of Health, Fredericton, NB.
⁷ Prince Edward Island Department of Health and Wellness, Population Health Assessment & Surveillance Unit, Charlottetown, PE.
⁸ Public Health Branch, Nova Scotia Department of Health and Wellness, Halifax, NS.
⁹ Health and Community Services, Population Health Branch, St. John's, NL.
¹⁰ Direction générale adjointe de la protection de la santé publique, Ministère de la Santé et des Services sociaux, Québec, QC.
¹¹ Communicable Diseases and Immunization Service, BC Centre for Disease Control, Vancouver, BC.
¹² Centre for Food-borne, Environmental and Zoonotic Infectious Diseases, Public Health Agency of Canada, Ottawa, ON.

Abstract

Background: Lyme disease (LD) is a multisystem infection that can affect the skin, heart, joints and nervous system. In Canada, the incidence of LD cases has increased over the past decade making this a disease of public health concern. The objective of this study is to summarize the epidemiology of LD cases reported in Canada from 2009 through 2019.

Methods: Incidence over time, case classification (confirmed and probable), seasonal and geographic distribution, demographic and clinical characteristics of reported LD cases were determined. Logistic regression was used to explore potential demographic risk factors for the occurrence of LD.

Results: During 2009-2019, a total of 10,150 LD cases were reported by the provinces to the Public Health Agency of Canada, of which 7,242 (71.3%) were confirmed and 2,908 (28.7%) were probable cases. The annual count increased from 144 in 2009 to 2,634 in 2019, mainly due to an increase in locally acquired infections, from 65.3% to 93.6%, respectively. The majority of cases (92.1%) were reported from three provinces: Ontario (46.0%); Nova Scotia (28.0%); and Québec (18.1%). Most of the locally acquired cases (74.0%) were reported in the summer months of June (20.0%), July (35.4%) and August (18.6%). The highest incidence rates (cases per 100,000 population) were in children aged 5-9 years (45.0) and in adults aged 65-69 years (74.3), with 57.3% of all reported cases occurring among males. The most common presenting symptoms were single erythema migrans rash (75.1%) and arthritis (34.1%). The frequency of reported clinical manifestations varied among age groups and seasons with erythema migrans and arthritis at presentation reported more frequently in children than older patients.

Conclusion: The results of this report highlight the continued emergence of LD in Canada and the need for further development and implementation of targeted awareness campaigns designed to minimize the burden of LD.

Keywords: Canada; Ixodes pacificus; Ixodes scapularis; Lyme disease; surveillance; tick-borne disease.

Public Health Agency of Canada, 2022.