The Durham Region Health Department has confirmed four cases of measles in the area as of March 18, 2026. This health update affects residents throughout the region, including Ajax, Ontario, as officials track potential exposures in public spaces.
The first three cases were identified in children from the same household who were not vaccinated. A fourth case was confirmed on March 18, 2026, which health officials linked to a previously identified exposure site.
Officials identified potential exposure sites at the Lakeridge Health Oshawa Emergency Department and on a Durham Region Transit bus. These exposures occurred on March 15 and March 16, 2026; the transit exposures specifically involved the Route #901 Simcoe bus service.
Residents are encouraged to check their health records to ensure their vaccinations are up to date. Health officials ask that anyone showing symptoms call their doctor or a medical clinic before visiting in person to avoid spreading the illness to others.
