title: Travel-acquired infections and illnesses in Canadians: surveillance report from CanTravNet surveillance data, 2009-2011.
abstract: BACKGROUND
  Important knowledge gaps exist in our understanding of migration medicine practice and the impact of pathogens imported by Canadian travellers. We present here a comprehensive, Canada-specific surveillance summary of illness in a cohort of returned Canadian travellers and new immigrants.
  
  
  METHODS
  We extracted and analyzed (using standard parametric and nonparametric techniques) data from the Canadian Travel Medicine Network (CanTravNet) database for ill returned Canadian travellers and new immigrants who presented to a Canadian GeoSentinel Surveillance Network site between September 2009 and September 2011.
  
  
  RESULTS
  During the study period, 4365 travellers and immigrants presented to a CanTravNet site, 3943 (90.3%) of whom were assigned a travel-related diagnosis. Among the 3115 non-immigrant travellers with a definitive travel-related diagnosis, arthropod bite (n = 127 [4.1%]), giardiasis (n = 91 [2.9%]), malaria (n = 77 [2.5%]), latent tuberculosis (n = 73 [2.3%]), and strongyloidiasis (n = 66 [2.1%]) were the most common specific etiologic diagnoses. Among the 828 immigrants with definitive travel-related diagnoses, the most frequent etiologies were latent tuberculosis (n = 229 [27.7%]), chronic hepatitis B (n = 182 [22.0%]), active tuberculosis (n = 97 [11.7%]), chronic hepatitis C (n = 89 [10.7%]), and strongyloidiasis (n = 41 [5.0%]). Potentially serious infections, such as dengue fever (61 cases) and enteric fever due to Salmonella enterica serotype Typhi or Paratyphi (36 cases), were common. Individuals travelling for the purpose of visiting friends and relatives (n = 500 [11.6% of those with known reason for travel]) were over-represented among those diagnosed with malaria and enteric fever, compared with other illnesses (for malaria 34/94 [36.2%] v. 466/4221 [11.0%]; for enteric fever, 17/36 [47.2%] v. 483/4279 [11.3%]) (both p < 0.001). For cases of malaria, there was also overrepresentation (compared with other illnesses) from business travellers (22/94 [23.4%] v. 337/4221 [8.0%]) and males (62/94 [66.0%] v. 1964/4269 [46.0%]) (both p < 0.001). Malaria was more likely than other illnesses to be acquired in sub-Saharan Africa (p < 0.001), whereas dengue was more likely than other illnesses to be imported from the Caribbean and South East Asia (both p = 0.003) and enteric fever from South Central Asia (24/36 [66.7%]) (p < 0.001).
  
  
  CONCLUSIONS
  This analysis of surveillance data on ill returned Canadian travellers has detailed the spectrum of imported illness within this cohort. It provides an epidemiologic framework for Canadian practitioners encountering ill returned travellers. We have confirmed that travel to visit friends and relatives confers particularly high risks, which underscores the need to improve pretravel intervention for a population that is unlikely to seek specific pretravel advice. Potentially serious and fatal illnesses such as malaria and enteric fever were common, as were illnesses of public health importance, such as tuberculosis and hepatitis B.
authors.affiliation: Andrea K. Boggild, MSc, MD, DTMH, FRCPC, is the Clinical Director of the Tropical Disease Unit and a Staff Physician in the Division of Infectious Diseases, University Health Network - Toronto General Hospital; Assistant Professor, Department of Medicine, University of Toronto; and the Parasitology Lead with Laboratory Services, Public Health Ontario, Toronto, Ontario.
authors.forename: Andrea K
authors.initials: AK
authors.lastname: Boggild
authors.affiliation: Jennifer Geduld, MHSc, BSc, is Manager, Epidemiology with the Travel and Migration Health Division, Infectious Disease Prevention and Control Branch, Public Health Agency of Canada, Ottawa, Ontario.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Geduld
authors.affiliation: Michael Libman, MD, is Director of the Centre for Tropical Diseases, Director of the Division of Infectious Diseases, and member of the Department of Microbiology, McGill University Health Centre, Montreal, Quebec.
authors.forename: Michael
authors.initials: M
authors.lastname: Libman
authors.affiliation: Brian J. Ward, MSc, MDCM, DTM&H, is Professor of Medicine and Microbiology, Division of Infectious Diseases, Department of Microbiology, McGill University Health Centre, Montreal, Quebec.
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Ward
authors.affiliation: Anne E. McCarthy, MD, FRCPC, DTM&H, is Professor of Medicine, University of Ottawa, and Director of the Tropical Medicine and International Health Clinic, The Ottawa Hospital-General Campus, Ottawa, Ontario.
authors.forename: Anne E
authors.initials: AE
authors.lastname: McCarthy
authors.affiliation: Patrick W. Doyle, MD, MHSc, FRCPC, is Medical Microbiologist with the Division of Medical Microbiology and Infection Control, Vancouver General Hospital, and Clinical Professor, Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, British Columbia.
authors.forename: Patrick W
authors.initials: PW
authors.lastname: Doyle
authors.affiliation: Wayne Ghesquiere, MD, FRCPC, is an Infectious Diseases and Internal Medicine Consultant and Section Chief of Infectious Diseases with the Vancouver Island Health Authority, Victoria, British Columbia, and Clinical Assistant Professor of Medicine, University of British Columbia, Vancouver, British Columbia.
authors.forename: Wayne
authors.initials: W
authors.lastname: Ghesquiere
authors.affiliation: Jean Vincelette, MD, is Full Clinical Professor with the Département de microbiologie médicale et infectiologie, Hôpital Saint-Luc, Centre hospitalier de l'Université de Montréal, Montreal, Quebec.
authors.forename: Jean
authors.initials: J
authors.lastname: Vincelette
authors.affiliation: Susan Kuhn, MD, is Head, Section of Pediatric Infectious Diseases, and Associate Professor, Departments of Pediatrics and Medicine, University of Calgary, Calgary, Alberta.
authors.forename: Susan
authors.initials: S
authors.lastname: Kuhn
authors.affiliation: David O. Freedman, MD, is Professor of Medicine and Epidemiology and Director of the UAB Travelers Health Clinic with the Gorgas Center for Geographic Medicine, Division of Infectious Diseases, University of Alabama at Birmingham, Birmingham, Alabama.
authors.forename: David O
authors.initials: DO
authors.lastname: Freedman
authors.affiliation: Kevin C. Kain, MD, FRCPC, is Co-Director of the Tropical Disease Unit and a Professor of Medicine, Division of Infectious Diseases, Department of Medicine, University Health Network - Toronto General Hospital and University of Toronto, and Director of the Sandra A. Rotman Laboratories, Sandra Rotman Centre, University Health Network, Toronto, Ontario.
authors.forename: Kevin C
authors.initials: KC
authors.lastname: Kain
mesh_terms: D002170:Canada / Q000453:epidemiology; D015331:Cohort Studies; D003141:Communicable Diseases / Q000453:epidemiology*; D054242:Emigrants and Immigrants / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D038622:Internationality; D008297:Male; D011159:Population Surveillance; D018571:Sentinel Surveillance; D014195:Travel / Q000706:statistics & numerical data*