Nearly three times more measles cases in Canada than U.S. right now, according to public health data

Isaac Bogoch, an infectious diseases specialist, comments on the measles cases in Canada and the U.S.

Canada has nearly three times more confirmed measles cases than the United States right now, according to recent public health data.

Canada this year has seen a total of 3,822 measles cases, reported in 10 provinces and territories. Data by federal public health officials updated Monday shows 3,517 cases are considered confirmed and 305 are “probable.” One death was reported in Ontario. The latest available data reflects case information collected up until July 5.

The Canadian provinces with the most reported cases this year are Ontario at 2,245, Alberta at 1,231 and Manitoba at 138. Government officials didn’t break down which of these cases are confirmed.

The data is “likely an underestimate” of the total in Canada, the federal government wrote on its website, noting it only represents reported cases and that there is a “small reporting delay.”

Meanwhile in the U.S., a total of 1,309 confirmed measles cases were reported in 40 states, according to the latest numbers posted on the U.S. Centers for Disease Control and Prevention website Tuesday. It didn’t provide the number for probable cases.

Three people have died this year in the U.S. due to measles, the CDC says.

Limitations in data

Dr. Isaac Bogoch, an infectious diseases specialist at the Toronto General Hospital, said the trend is concerning, with measles largely affecting unvaccinated individuals.

“It’s unacceptable to have measles outbreaks in Canada, especially this size,” he said in a video interview with CTVNews.ca on Wednesday. “I think it’s obvious that there is a large measles outbreak in Canada and in the United States, and it’s extremely important that both countries take steps to curb these outbreaks and to prevent future infections.”

He said it’s important to know that there are “limitations” in data, including possible “reporting biases.”

There are differences in how data is collected and reported in each country, he added.

Southern Ontario and southern Alberta are the areas affected the most, he said, but fewer cases are being reported each week in southern Ontario, a “downward” trend that began around late April. Meanwhile, he said, Alberta has shown signs of improvement over the last few weeks, though not as strongly as in Ontario.