Two thousand seventeen is turning into a banner year for measles. Europe, Africa and parts of Asia have been hit hard, and outbreaks here at home tell us Canadians can’t be complacent.
In Europe, Romania tops the list with more than 3,400 cases and 17 deaths. Italy has at least 400 cases so far this year. France, Germany, Poland, Switzerland, the UK and Ukraine have also reported cases. In Africa, Guinea has close to thirty-five hundred. Nigeria is dealing with an outbreak. In Asia, Mongolia is dealing with one of the largest outbreaks yet. That country has seen 20,000 cases – just three years after the country was declared free of measles. Worldwide, measles kills 400 children a day.
Authorities think several reasons are behind what is happening. One is that vaccine rates have flattened out. The World Health Organization estimates that vaccine rates sit at around 78 per cent. Outbreaks occur when herd immunity is depressed. Experts in infectious diseases say that countries require 90 to 95 per cent of the population vaccinated against the measles for the human herd to be strong enough to prevent local outbreaks.
A second factor is that measles is a highly contagious virus. On average, one person infected spreads the disease to 18 others. You don’t have to be in direct contact with an infected person. Just being in a room an hour after they were present may be enough to get it. Measles outbreaks can happen in any country, but they more likely to be bigger in countries with a lower standard of living.
Here at home, as of last week, Nova Scotia had 20 cases of measles since the start of the year. A new case has been identified in New Brunswick.The province’s deputy chief medical officer of health said the outbreak ls likely due to international travel. Late last month, a reports surfaced that a member of the crew of a Westjet flight was diagnosed with measles – and may have exposed passengers on several flights – including flights from Abbotsford to Calgary, Calgary to Ottawa, Ottawa to Toronto, Toronto to Montreal, as well as flights between Toronto and Providenciales as well as Turks and Caicos. During the same period of time, passengers bound for Canada may have been exposed to the virus while traveling from Delhi to Toronto via Dubai on Emirates Airlines flights.
This is slightly off topic, but Toronto has had 68 confirmed cases of mumps. A spokesperson for the city’s health authority, said it’s likely that someone, or many people, travelled to a place where mumps was circulating, and brought it back to Toronto.
People are wondering what puts Canadians at risk of measles. In Nova Scotia, the deputy chief medical officer of health said measles vaccination rates are at around 85 per cent for school age children. That’s better than the world wide rate of 78 per cent. However, given how communicable measles is, it would not surprise me if a 15 per cent unvaccinated rate would be high enough for a local outbreak to occur.
And, there’s another factor at play. When the MMR vaccine came out in the 1970s, kids received one dose. It wasn’t until the 1990’s that authorities recognized that people need a second dose of MMR vaccine to get to immunity levels approaching 99 per cent. In the mid to late 1990’s, the provinces conducted ‘catch-up’ campaigns to give people a second shot that they missed in the 1970’s. Nevertheless, some Canadians missed out on the second booster, and as a result, they are vulnerable to getting the measles.
Canada’s interim chief medical officer of health is advising people traveling to abroad to check for measles hot spots. Dr. Theresa Tam recommends that Canadians who need a booster should get one six weeks before traveling – since that is how long it takes develop antibodies that protect you from the virus. She added that anyone who needs the vaccine should not wait to travel, but should get the shot as soon as possible.
Age is the determining factor in assessing your need for a booster. Adults age 20 to 40 years may have only gotten one dose of MMR – and therefore need a second dose. In Nova Scotia, the bulk of the patients getting measles in the current outbreak are in their 20s and 30s, which is in keeping wih expectations. Adults born before 1970 are presumed to have gotten the measles, and therefore have natural immunity. Kids routinely get two doses of MMR, and should be fully immunized.
These age-related recommendations apply only to people who lived and received health care in Canada during the relevant times.
If there is any doubt, check with your doctor. This is one disease you don’t want to risk.
Note: the fatality rate in kids has been corrected from a previous version.