The World Health Organization (WHO) is warning of a "relentlessly increasing threat to children" across the globe from measles.
Last year, measles cases increased by 18 per cent to nine million worldwide, according to a joint report from the WHO and U.S. Centers for Disease Control and Prevention (CDC).
Measles deaths jumped 43 per cent compared to the previous year, with 136,000 reported deaths in 2022. Most cases and deaths were among children in low-income countries, the report stated.
"The increase in measles outbreaks and deaths is staggering, but unfortunately, not unexpected given the declining vaccination rates we've seen in the past few years," said John Vertefeuille, director of CDC's Global Immunization Division, in a press release.
Measles typically begins with symptoms such as fever, cough, runny nose or watery eyes. The telltale rash appears several days after the first symptoms.
In 2022, large measles outbreaks were reported in 37 countries compared to 22 countries from the year before.
In Canada, data from the federal government show three active measles cases in the country. A total of 10 cases have been reported all year. In 2022, just three cases were reported. No cases were reported in 2021.
According to Dr. Isaac Bogoch, a Toronto-based infectious disease specialist, travellers import most of Canada's measles cases into the country. He expects cases to rise as global travel begins to ramp up.
"The key thing here is to prevent secondary transmission within the country and obviously provide impeccable care to people who are landing in Canada with measles infections," Bogoch said.
"It's really unfortunate that we still are dealing with this problem that, quite frankly, should not be an issue in 2023."
The disease is highly preventable, Bogoch said, with two vaccine doses typically administered as routine childhood vaccinations.
However, years of declining vaccination rates are to blame for an increase in measles cases, the CDC said.
Data from Toronto Public Health shows just 22 per cent of Grade 12 students in that city were up to date on their routine vaccinations at the beginning of the 2022-23 school year. Vaccination rates were at nearly 90 per cent pre-pandemic.
Dr. Stephen Elledge, a professor at Harvard Medical School, said the pandemic played a large role in declining vaccination rates declines for two reasons.
Many people felt unsafe going to hospitals or clinics during the pandemic, he said, therefore putting and put off routine vaccinations, as a result. Others became vaccine hesitant following the flood of misinformation being shared.
"We really have a lot of work to do to convince people of the safety of these vaccines. Certainly there's a long history of measles vaccines being given and being well-tolerated," Elledge said.
As preventable as the measles is, they are it is just as contagious.
"Measles is the most infectious (disease) known to man," Elledge said, adding it would take about a 95 per cent vaccination rate to achieve herd protection in a population.
The global vaccine coverage rate of the first dose sits at 83 per cent and the second dose is at 74 per cent, according to the WHO.
While measles can be deadly, Elledge said the milder outcomes still result in long-lasting effects. The disease can damage a person's immune system and pre-existing immune memory, which means other illnesses could be that much harder to fight off.
"You are now in a danger zone for two years. Your kids are in the danger zone. Elderly people are in the danger zone," Elledge said.
"People need to realize that this one vaccine is extremely important and they need to get their kids vaccinated."
Bogoch agreed that vaccines need to be taken more seriously.
He said the increase in measles could be a warning sign that outbreaks in other vaccine-preventable illnesses are right around the corner.