title: Analysis of the human population bitten by Ixodes scapularis ticks in Quebec, Canada: Increasing risk of Lyme disease.
abstract: Ixodes scapularis, the main vector of Borrelia burgdorferi, the spirochetal agent of Lyme disease, is expanding its range in southern Canada and bringing risk to the public from Lyme disease. The aims of this study were to (i) describe how risk of Lyme disease in Quebec, Canada, has changed from 2008 to 2014 by analysis of the number of tick submissions, the geographic scope of ticks submitted and the prevalence of B. burgdorferi in ticks removed from people and submitted through the Quebec passive tick surveillance program and (ii) explore whether exposure to ticks is influenced by age and sex. Ticks were collected from 2008 to 2014 in a passive surveillance program conducted by the Laboratoire de santé publique du Québec (LSPQ), and tested by PCR for B. burgdorferi at the National Microbiology Laboratory. The number of ticks submitted each year more than quadrupled during the study period (from 174 in 2008 to 962 in 2014), increases in the geographic range and geographic uniformity of submissions amongst municipalities were observed, and infection prevalence in the ticks (mostly adult females) submitted rose from 5.9% in 2008 to 18.1% in 2014. These data are consistent with outcomes from active surveillance for blacklegged ticks. More men (54.4%) than women (45.6%) were bitten by I. scapularis ticks and the frequency of tick submission was highest in children under 15 years of age and in the adults 50-70 years old. These findings demonstrate the utility of conducting passive tick surveillance using humans and provides information on risk groups (i.e., males, children under 15, adults older than 50, and those living in the more southern parts of the province) to which information on personal protection and tick-bite prevention should be most strongly targeted.
authors.affiliation: Institut National de Santé Publique du Québec, Laboratoire de Santé Publique du Québec, 20045, Chemin Sainte-Marie, Sainte-Anne-de-Bellevue, Quebec H9X 3R5, Canada; Zoonoses Division & Special, Public Health Agency of Canada, 3200 Sicotte, Saint-Hyacinthe, Quebec J2S 7C6, Canada. Electronic address: salima.gasmi@inspq.qc.ca.
authors.forename: Salima
authors.initials: S
authors.lastname: Gasmi
authors.affiliation: Zoonoses Division & Special, Public Health Agency of Canada, 3200 Sicotte, Saint-Hyacinthe, Quebec J2S 7C6, Canada; Groupe de Recherche en Épidémiologie des Zoonoses et Santé Publique (GREZOSP), 3200 Sicotte, Saint-Hyacinthe, Quebec J2S 7C6, Canada. Electronic address: nicholas.ogden@phac-aspc.gc.ca.
authors.forename: Nicholas H
authors.initials: NH
authors.lastname: Ogden
authors.affiliation: Faculty of Veterinary Medicine, University of Montreal, 3200 Sicotte, Saint-Hyacinthe, Quebec J2S 7C6, Canada. Electronic address: patrick.a.leighton@umontreal.ca.
authors.forename: Patrick A
authors.initials: PA
authors.lastname: Leighton
authors.affiliation: Zoonotic Diseases & Special Pathogens Division, National Microbiology Laboratory, Public Health Agency of Canada, 1015 Arlington Street, Winnipeg R3E 3R2, Canada. Electronic address: robbin.lindsay@phac-aspc.gc.ca.
authors.forename: L Robbin
authors.initials: LR
authors.lastname: Lindsay
authors.affiliation: Institut National de Santé Publique du Québec, Laboratoire de Santé Publique du Québec, 20045, Chemin Sainte-Marie, Sainte-Anne-de-Bellevue, Quebec H9X 3R5, Canada. Electronic address: karine.thivierge@inspq.qc.ca.
authors.forename: Karine
authors.initials: K
authors.lastname: Thivierge
mesh_terms: D000818:Animals; D006801:Humans; D018884:Ixodes / Q000502:physiology*; D008193:Lyme Disease / Q000453:epidemiology* / Q000635:transmission*; D011159:Population Surveillance; D011792:Quebec / Q000453:epidemiology; D012307:Risk Factors; D064927:Tick Bites / Q000453:epidemiology*
keywords: Ixodes scapularis; Lyme disease; Passive tick surveillance; Range expansion; Tick distribution