Health authorities in B.C. and Washington State are warning several cases of measles have been reported on both sides of the border this week.
The B.C. Centre for Disease Control says three cases were reported on Bowen Island and the North Shore this week.
The Whatcom County Health Department, says an infected person visited Costco and Bellis Fair Mall on June 22.
Health officials say there is no cause for panic because most people have been vaccinated for measles.
But for those who have not been vaccinated measles is highly contagious airborn infection that can remain in the air for up to two hours after someone infected has left a room.
It usually starts with a fever, runny nose, cough and red watery eyes before progressing to a rash on the face and body.
Dr. Patricia Daly, the chief medical officer at Vancouver Coastal Health, advises anyone with symptoms to see a doctor and try to avoid infecting others.
"One thing people need to know is that measles can be very, very contagious so if you do have a fever and rash and you're concerned that you have measles it's a good idea to call your doctor's office in advance," said Daly.
"Perhaps they can see you at the end of the day and ensure that when you come in they can put a mask on you so that you don't expose other people."
According to the BCCDC the last significant measles outbreak occurred in 2010 in British Columbia when 82 case were confirmed after the Winter Olympic Games held in Vancouver.
That was the largest measles outbreak in B.C. since 1997 when 247 cases were reported. Officials blamed the 2011 outbreak on low vaccination rates.
- read more about the 2010 outbreak
There were 10 confirmed measles cases among B.C. residents in 2011.
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