Measles detected in Montreal child as cases increase in northeastern U.S.

A case of measles in a Montreal child was reported to officials on Tuesday.

The infection was likely contracted during a trip to Africa, according to Montreal Public Health, and the infectious period is believed to have lasted from Jan. 29 to Feb. 6.

Once back in Montreal, the child attended a school on Jan. 29, visited a medical clinic on Jan. 31, and went to the emergency departments of two pediatric hospitals between Jan. 31 and Feb. 2.

"Intervention is underway with all contacts in these environments," Public Health confirmed via email Wednesday.

No additional cases of measles have been reported in Montreal since Tuesday.

The disease is highly contagious. Symptoms usually begin with a fever, cough, and runny nose, with a red rash appearing a few days in. 

Measles resurgence

Dr. Earl Rubin is the division director of pediatric infectious diseases at the Montreal Children's Hospital and said there is a resurgence of measles worldwide, particularly in the northeast of the United States.

"Most likely, it's a combination of those who are not immunized with international travel going or coming from areas of the world where there is poor vaccination and cases of measles that continue to circulate," he said.

The MMRV vaccine, which protects against measles, mumps rubella, and varicella is typically administered at 12 and 18 months and has a 98 per cent effectiveness rate after both doses. The vaccine schedule is not mandatory in Quebec, said Rubin.

Of the cases noted in the U.S., the majority were unvaccinated children, Rubin added.

"So it's a grave concern to those who are unvaccinated and exposed and are at increased risk of having complications of the illness," he said. "Anybody of any age can have complications, but predominantly in infants, when those who are immunocompromised and pregnant women who are not vaccinated can have complications of having measles."

Rubin said that measles is one of the most contagious infectious illnesses known to man. Older studies found, he said, that transmission occurred between a unvaccinated person who was in a room after the infected person had left it over an hour prior.

"With better hospital construction, better air exchanges, it's probably not as long as that is but it still is a concern," he said. "It is incredibly contagious. So, to answer your question, should people be concerned? Yes, if they're not vaccinated."

Rubin said COVID-19 pandemic lockdown restrictions caused a decrease in vaccinations due to lack of access to doctors' offices. In addition, vaccine skepticism has decreased the numbers.

"It's frustrating and concerning," he said." We currently just have this one case for my child who came from Africa, but because it's so contagious, there is that concern that we will see more cases."

One dose of the measles vaccine in children between 12 and 15 months of age is estimated to be 85 to 95 per cent effective, while two doses are almost 100 per cent effective, according to Canada's official immunization guide.

Public Health did not immediately confirm whether the infected child in Montreal was vaccinated.