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A woman with a Mickey Mouse hat walks toward Sleeping Beauty's Castle at Disneyland, Thursday, Jan. 22, 2015, in Anaheim, Calif. California public health officials urged those who haven't been vaccinated against measles to avoid Disney parks where a spreading outbreak originated.Jae C. Hong/The Associated Press

B.C. travellers looking to spend spring break in Disneyland should make sure their vaccines are up to date before heading to the theme park, health authorities in British Columbia are warning.

The California Department of Public Health (CPDH) confirmed last Friday that a measles outbreak in Disneyland has already infected 77 people in the United States and one in Mexico. The disease could spread to Canada.

"A typical scenario would be a visitor from British Columbia, who's unvaccinated or perhaps has only received a single dose, visits Disney, gets infected, and comes back," said Dr. Monika Naus, medical director of immunization at BC Centre for Disease Control.

People born after 1970 are at risk of getting measles if they don't have a second dose of the vaccine, says the Vancouver Coastal Health travel clinic website. Those born before 1970 have acquired natural immunity to the disease.

The mumps-measles-rubella (MMR) vaccine protects against a measles infection. Ninety to 95 per cent of people who take the first dose of the vaccine are protected and 99 per cent are protected after taking the second dose, Dr. Naus said.

Disneyland is known as a hot spot for infection, and measles is the most infectious disease doctors recognize, Dr. Naus said.

"In the era before vaccination, when people were susceptible, each case generated about 18 secondary cases," she said.

The province witnessed its own outbreak in March last year, when 433 people were infected in the Fraser Valley, said Dr. Suni Boraston, director of the travel clinic at Vancouver Coastal Health.

"I don't think people should be worried," Dr. Boraston said about measles spreading to B.C. The main lesson learned from last year's outbreak is "vaccinate your children," she said.

Interest in vaccination rises every time there is provincewide outbreak such as the 2008 mumps outbreak or the 2010 measles outbreak, said Dr. Naus. The surge in demand for the MMR vaccine in B.C. in these cases is about 10,000 doses beyond the expected routine use.

The recent outbreak of mumps in the National Hockey League didn't lead to a rise in MMR vaccination, but it helped to raise the profile of the disease and gave doctors an opportunity to provide information on the importance of adult vaccination, said Dr. Naus. More than 15 players were diagnosed, including Canadian star Sidney Crosby, who plays for the Pittsburgh Penguins.

The MMR vaccine is a live-virus vaccine and is not recommended for people who have a compromised immune system, such as those battling leukemia or lymphoma, said Dr. Boraston. Doctors also don't like to vaccinate pregnant women with a live virus, she said.

Historically, people who didn't get vaccinated lacked the means to do so, said Dr. Naus. Today, doctors find that people don't get vaccinated because of firmly held beliefs.

"There's anything from conspiracy theorists who think that this is a government plot or industry plot … and then there are people who still believe that vaccines and thimerosal cause autism, or that somehow natural immunity is better than vaccine-acquired immunity," Dr. Naus said.

Possible symptoms of measles are a cough and cold symptoms that include a runny nose, fever and red eyes. A rash breaks out about three days after those symptoms begin. Measles can lead to pneumonia, and less commonly, encephalitis, or infection of the brain, and death, said Dr. Naus.

The incubation period for the disease can range between seven to 21 days, meaning the disease can appear as soon as one week after exposure. Individuals may be infectious even before the emblematic rash appears and are infectious for about a week to 10 days, Dr. Naus said.