Abstract
Endemic cryptosporidiosis in Ontario was studied using notifiable disease data from the Ontario Ministry of Health for the years 1996–1997 inclusive. For this study period, 451 endemic cases were identified, corresponding to a provincial mean annual age-and sex-adjusted incidence rate of 2.13 cases per 100,000. Children under five years of age had the highest incidence of disease. Males had a higher incidence than females, except for those 15–19 years of age. Five percent of cases were reported as HIV-positive or having AIDS. The proportion of cases occurring between July and November inclusive (63%) was significantly higher than expected (42%) assuming no seasonal variation (p<0.01). The proportion of rural cases observed (29%) was significantly higher than expected (17%) based on the Ontario population (p<0.01). Travel to or prior residence in an endemic area was identified in 22% of the cases where a risk setting was reported (n=265).
Résumé
Nous avons étudié les cas endémiques de cryptosporidiose déclarés en Ontario pour les années 1996 et 1997 en utilisant la base de données des maladies à déclaration obligatoire du ministère de la Santé de cette province. Durant la période de référence, 451 cas endémiques ont été signalés, ce qui correspond à un taux moyen de 2,13 cas pour 100 000 habitants, ajusté selon l’âge et le sexe. Les enfants de moins de cinq ans présentaient le plus haut taux d’incidence de la maladie. Sauf chez les hommes de 15 à 19 ans, le taux d’incidence chez les hommes était plus élevé que chez les femmes. Cinq pour cent des cas déclarés étaient séropositifs pour le VIH ou avaient le sida. La proportion des cas déclarés entre juillet et novembre inclusivement (63 %) était sensiblement supérieure à celle attendue (42 %) dans l’hypothèse qu’il n’y ait eu aucune variation saisonnière (p<0,01). La proportion des cas ruraux observés (29 %) était elle aussi sensiblement supérieure à celle attendue (17 %) par référence à la population de l’Ontario (p<0,01). Un voyage ou un séjour dans une région où la cryptosporidiose est endémique figurait dans 22 % des cas associés à la présence d’un milieu à risque (n=265).
Footnotes
Funding for this project was provided by the Laboratory Centre for Disease Control, Health Canada.
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