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Canadian Journal of Public Health

, Volume 92, Issue 5, pp 361–365 | Cite as

A Descriptive Analysis of Giardiasis Cases Reported in Ontario, 1990–1998

  • Judy D. Greig
  • Pascal Michel
  • Jeff B. Wilson
  • Anna M. Lammerding
  • Shannon E. Majowicz
  • Julie Stratton
  • Jeffery J. Aramini
  • Rob K. Meyers
  • Dean Middleton
  • Scott A. McEwen
Article

Abstract

Cases of giardiasis in Ontario were described using notifiable disease data from the Ontario Ministry of Health for the years 1990–1998 inclusive. The mean annual age-and sex-adjusted incidence rate was 25.77 cases per 100,000 population for the 25,289 cases reported. Children under five years of age had the highest incidence of disease. Males had a higher mean annual incidence in all age groups. Four deaths occurred among cases. The most frequently reported symptoms were loose stools or watery diarrhea (50.1%). A seasonal pattern was noted, peaking in late summer and early autumn. The most frequently reported probable risk settings were the home (40.1%) and travel (39.1%). The study findings suggest that a high proportion of cases occur in urban areas and spatial analysis showed the highest incidence around Lake Huron and Georgian Bay. Unfiltered water and person-to-person contact are believed to be important sources of infection.

Résumé

Les cas de giardiase de la province de l’Ontario ont été décrits à partir du fichier des maladies à déclaration obligatoire du ministère de la Santé de cette province pour les années 1990 à 1998 inclusivement. Le taux moyen standardisé selon le sexe et l’âge, calculé pour les 25 289 cas déclarés, était de 25,77 cas pour 100 000 habitants. Les enfants de moins de cinq ans avaient le plus haut taux d’incidence de la maladie. Les mâles présentaient un taux d’incidence moyen annuel supérieur dans tous les groupes d’âge. Quatre décès ont été rapportés parmi les cas. Les symptômes les plus fréquemment déclarés étaient les selles liquides ou la diarrhée aqueuse (50,1 %). Nous avons remarqué une tendance saisonnière avec un sommet en fin d’été et en début d’automne. Les cadres de risque le plus souvent déclarés étaient la maison (40,1 %) et les voyages (39,1 %). Les résultats de cette étude suggèrent qu’une proportion élevée des cas se produisent en milieu urbain, et que l’eau non filtrée et les contacts personnels constituent d’importantes sources d’infection. Une analyse spatiale révèle que les taux d’incidence les plus élevés se situaient autour du lac Huron de la baie Georgienne.

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Copyright information

© The Canadian Public Health Association 2001

Authors and Affiliations

  • Judy D. Greig
    • 1
    • 2
  • Pascal Michel
    • 1
    • 2
  • Jeff B. Wilson
    • 1
    • 2
  • Anna M. Lammerding
    • 2
  • Shannon E. Majowicz
    • 2
  • Julie Stratton
    • 2
    • 3
  • Jeffery J. Aramini
    • 1
    • 2
  • Rob K. Meyers
    • 2
  • Dean Middleton
    • 4
  • Scott A. McEwen
    • 1
  1. 1.Department of Population Medicine, Ontario Veterinary CollegeUniversity of GuelphGuelphCanada
  2. 2.Population and Public Health BranchHealth CanadaGuelphCanada
  3. 3.Field Epidemiology Training Program, LCDCHealth CanadaCanada
  4. 4.Disease Control Service, Public Health BranchOntario Ministry of Health and Long-Term CareTorontoCanada

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