Four cases of mumps have been confirmed in Brampton and Mississauga, according to Peel Public Health.
Three of the cases are in Mississauga and one is in Brampton, the region's associate medical officer of health, Dr. Monica Hau, said Wednesday..
Two men and two women are affected and range in age from 19 to 43.
"Based on our follow-up on the confirmed cases, we believe the risk of spread from these cases to the general public is minimal," Hau said in a statement e-mailed to CBC Toronto.
Hau said the region will continue to monitor and reassess this situation to see if a broader public notification becomes necessary.
Toronto is also dealing with a mumps outbreak with 40 confirmed cases in the city, according to Toronto Public Health.
Most of the cases are among people 18 to 35 years old, but four of the cases are related to schools in Toronto, either among staff or students, according to the city of Toronto website.
Peel Public Health says the four patients do not have any direct links to Toronto's cases, but most of them have visited locations in downtown Toronto.