Figure 1. . . Locations of persons from whom 990 blood samples were taken and tested for malaria by the Ontario Agency for Health Protection and Promotion, Ontario, Canada, 2008–2009. Red dots, malaria case-patients (positive test results); blue circles, controls (negative test results). A) All observations; B) the most significant space–time cluster for malaria patients (circle), greater Toronto area, during May 15–November 6, 2008 (relative risk 3.54; p<0.01).