A Hamilton woman has tested positive for the measles and may have exposed others to the virus, public health officials warn.

“This case may have led to exposure in public and health-care settings in Hamilton, Burlington… and Mississauga,” Hamilton Public Health Services said in a Sunday news release.

People who visited the following locations at certain times may be at risk:

Saturday March 22, 2014:

Skyzone Indoor Trampoline Park, 3636 Hawkestone Rd., Mississauga, 12:30 p.m. to 4:30 p.m.

The Queen’s Head pub, 400 Brant St., Burlington, 10 p.m. to 2 a.m.

Sunday March 23, 2014:

Mill Street & 5 American House, 324 Dundas St. E, Waterdown, 1 a.m. to 2 a.m.

Milestones Restaurant, 1200 Brant St., Burlington, 7 p.m. to midnight

Monday March 24, 2014:

Canada Post office, 17 Main St. N, Waterdown, 5 p.m. to 6 p.m.

Boston Pizza, 4 Horseshoe Cr., Waterdown, 5:15 p.m. to 10:30 p.m.

Wednesday March 26, 2014:

Lakeside Variety store, 721 Beach Blvd., Hamilton, 9:30 a.m. to 11:30 a.m.

Walmart, 90 Dundas St. E. Waterdown, 2 p.m. to 4:45 p.m.

People who visited these locations at the specified times, and have never received two doses of a measles vaccine, are asked to call the public health office in their region:

Hamilton Public Health Services at 905-546-2063 for Hamilton residents

Halton Public Health at 905-825-6000 for Region of Halton residents

Peel Public Health at 905-799-7700 for Region of Peel residents

Individuals who have had the measles in the past are not at risk.

A bad cough, runny nose, fever, sensitivity to light and red-watery eyes are symptoms commonly associated with a case of the measles. Spots with a white centre can also appear inside the mouth. A red rash may also appear and last for four to seven days.

About four days after infection, a rash starts at the face and moves down the body. White spots may appear inside the mouth.

The virus spreads easily to people who aren’t immune. Infants under a year of age, pregnant women and people with weakened immune systems can get particularly ill.

Complications can include ear infections, pneumonia, croup and brain inflammation.

“Measles is highly contagious to susceptible people from the beginning of the illness until four days after the rash first appears,” Dr. Hamidah Meghani, Hamilton’s associate medical doctor of health, said in the Sunday news release.

“To avoid spreading illness to others it’s important that ill individuals stay home.”