Computer-generated dot maps as an epidemiologic tool: investigating an outbreak of toxoplasmosis.

We used computer-generated dot maps to examine the spatial distribution of 94 Toxoplasma gondii infections associated with an outbreak in British Columbia, Canada. The incidence among patients served by one water distribution system was 3.52 times that of patients served by other sources. Acute T. gondii infection among 3, 812 pregnant women was associated with the incriminated distribution system.