Manitoba Health has confirmed two more cases of measles -- including a Winnipeg woman who was brought to hospital by ambulance.
This brings the number lab-confirmed cases in the province this year to four.
One of the new cases is a teenage boy from southeastern Manitoba, while the other is a woman in her 40s from the city.
In all four instances this year, the disease appears to have been acquired locally -- as opposed to through travel abroad.
"The third and fourth cases don't appear to be linked to each other, nor to the first two cases," said Dr. Elise Weiss, the province's deputy chief public health officer.
Manitoba confirmed its first case of measles on March 14 and a second case about 10 days later. Until then, there had not been more than one reported case of the disease in any year since 1992. And in most cases over that period, the illness was believed to have been travel-related.
On Thursday, public health officials said in a press release people who were at the following Winnipeg locations should be aware of the possibility of infection:
- Polo Park Shopping Centre, March 22, between 11 a.m. and 1 p.m.;
- St. Vital Shopping Centre, March 22, between 1:30 p.m. and 2 p.m.; and
- St. Boniface General Hospital emergency room between 9:45 p.m., March 26 and 11:30 p.m., March 27.
The provincial news release made it appear a measles sufferer languished for nearly 26 hours in the St. Boniface ER waiting room.
However, late Thursday, the Winnipeg Regional Health Authority clarified that a local woman was brought to the St. Boniface hospital by ambulance, triaged and quickly taken to a part of the emergency department that is separate from the waiting area.
"There was no exposure to the waiting area," said WRHA spokeswoman Bronwyn Penner-Holigroski. "I don't want people to think that if they were sitting in the waiting area at that time that they would have been exposed."
The woman was later admitted to hospital.
Weiss said Manitoba Health will notify the public about certain locations that an infected person visited if it's impossible to determine who they may have come into contact with. In the case of a student attending school, the school and all affected families would be contacted directly, she said.
Generally, health-care workers attending a patient, family members and other people who have frequent contact with anyone infected are most at risk if they haven't been immunized, Weiss said.
If you happen to have been in a shopping mall at the same time as an infected person, there is some risk "but certainly it's lower-risk," she said.
Health officials have seen no evidence yet that Manitobans are stepping up immunizations for measles in the wake of the first two cases last month.
So far, there has been no increase in orders for the vaccine from doctors, medical clinics or public health offices, Weiss said. The immunization is free.
Meanwhile, Penner-Holigroski said hospital staff have identified all patients, visitors and workers who may have come into contact with the measles sufferer at St. Boniface. "And efforts are being made to reach out to each of them to notify them of potential exposure."
Manitoba isn't the only province coping with measles cases.
Health officials reported a case of measles in Edmonton on Thursday, the ninth in the province this year. The others include five cases in Calgary and three in central Alberta.
Last fall, there were 42 cases in the Lethbridge area. Officials believe the outbreak originated from one unvaccinated student.
The Alberta Health website shows measles-vaccination rates in 2012 were as low as 42 per cent in the Wabasca region. The provincial average was 84 per cent.
The provincial vaccination target is 98 per cent.
The Public Health Agency of Canada issued a notice Friday warning of a higher-than-usual number of measles cases this year. The illness has been reported in British Columbia, Alberta, Saskatchewan, Manitoba and Ontario.
B.C. has reported 320 confirmed cases in recent weeks, mostly in the Fraser Valley.
-- The Canadian Press files