A descriptive analysis of giardiasis cases reported in Ontario, 1990-1998.
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.
Greig
J D
JD
Department of Population Medicine, Ontario Veterinary College, University of Guelph, Guelph, ON. judy_greig@hc-sc.gc.ca
Michel
P
P
Wilson
J B
JB
Lammerding
A M
AM
Majowicz
S E
SE
Stratton
J
J
Aramini
J J
JJ
Meyers
R K
RK
Middleton
D
D
McEwen
S A
SA
D000328:Adult; D017677:Age Distribution; D000368:Aged; D002648:Child; D002675:Child, Preschool; D005260:Female; D005873:Giardiasis / Q000175:diagnosis / Q000453:epidemiology / Q000635:transmission; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009864:Ontario / Q000453:epidemiology; D011159:Population Surveillance; D012307:Risk Factors; D012621:Seasons; D017678:Sex Distribution