Public-health programs aim to immunize 95 per cent of the population through vaccination. Dr. Michael Kapusta gives vaccinations at St. Teresa's Separate School in Toronto in 1965.James Lewcun/The Globe and Mail
Dr. Frank Jagdis knows measles. As a medical student in the prevaccination 1960s and later as a practising pediatrician in Victoria, he saw the toll that measles took on children who came down with the viral infection.
"Measles was commonplace in those years," says Jagdis, 71, who retired from his practice four years ago. "We saw a lot of measles. And we saw measles complications as well."
The disease is marked by a splotchy-looking rash on the face and body, runny nose, sore throat and dry cough. Conjunctivitis leaves the eyes red, sensitive to light, and in some cases can cause corneal abrasions.
"They were very miserable," Jagdis says of the kids he saw. "The majority of them had fevers, and they did have good high fevers – 40 degrees."
While most young patients recovered from the disease, some developed complications.
"The most dreaded complication was encephalitis, which happened in about one in 1,000 [cases]," he says. "They get swelling of the brain, they can become comatose, they can get seizures and be left with permanent epilepsy if they survive."
Not all children did survive, recalls Jagdis, who says doctors expected to see one to three deaths per 1,000 cases. Some died as a result of encephalitis, others from bacterial pneumonia, another common complication of measles.
"People tend to forget the ones who died. That mortality is significant," he says. "You look at the public-health statistics, then you get an appreciation of what the mortality is."
Prior to 1970 when the MMR (measles, mumps and rubella) vaccine came into widespread use, the country often recorded tens of thousands of measles cases each year, according to Public Health Agency of Canada figures.
Death was common. From 1921 to the mid-1950s, measles killed hundreds of Canadians each year – more than 800 in 1926 and again in 1937 – before death figures began dipping into the double digits in the late 1950s and then into single-digit numbers from 1975 onward, Statistics Canada data show.
It was the introduction of the MMR vaccine under provincial universal-coverage programs that turned the tide on measles, public-health experts say – but not right away.
Initially, children were given a single MMR dose between 12 and 15 months of age. But with only one shot, says Jagdis, there was a failure rate of about 5 per cent, meaning one in 20 inoculated children didn't make protective antibodies and were able to catch – and spread – the disease.
It wasn't until the 1980s that Canada and other countries implemented a two-dose immunization regimen, with a second shot administered between the ages of four to six.
Even so, measles wasn't done for. In 1987, when the country recorded more than 3,000 cases, about 1,000 of them were in Victoria, and Jagdis was in the middle of the outbreak as head of the region's communicable-disease program.
"Measles spreads like wildfire," he says. "It's one of the most contagious illnesses that we have and that's one of the concerns."
The disease is transmitted when an infected person coughs or sneezes, sending virus-laden droplets into the air. The contagious period lasts about eight days – four days before the rash appears and four days after. Ninety per cent of unimmunized people who come in contact with a measles case will become infected themselves, says the U.S. Centers for Disease Control and Prevention.
While measles was declared officially eliminated in the Americas in 2002, cases imported by travellers cause sporadic outbreaks such as the ones now occurring in Ontario and Quebec, seeding the disease within the community and putting those without immunity at risk.
Public-health programs aim to immunize at least 95 per cent of the population though vaccination, says Dr. Natasha Crowcroft, chief of infectious diseases at Public Health Ontario.
But in recent years that target may have fallen short. An increasing number of parents have chosen not to have their children immunized for religious or philosophical reasons, including fears that the MMR vaccine may cause autism – a link that has been refuted by study after study.
"The vaccine is incredibly safe," says Crowcroft, noting that of 330,000 MMR doses given in Ontario last year, there were just 49 reports of side effects, virtually all of them mild, from tenderness at the injection site to slight fevers.
Without vaccination, she says, one in four infected children will have some kind of complication, from ear infections that pose a risk of full or partial deafness, to pneumonia, to encephalitis.
And even in modern times, measles continues to kill: Between 2000 and 2011, Canada recorded five deaths from the disease.
"It's much safer to have the vaccine than not to have the vaccine," she says. "And you really can't hide from measles. It travels in the air."
Jagdis echoes that sentiment, saying he believes so-called anti-vaxxers who eschew having their children immunized are "very short-sighted" and don't fully understand the science of vaccinations.
"Vaccines have saved countless lives in the course of human history and even in recent times we have had clear demonstrations of where vaccine lapses occurred and what happened," he says, citing the deaths of more than 1,000 children from diphtheria when the Soviet Union collapsed and immunization programs were severely disrupted.
"I think the situation right now," he says of the current Canadian measles outbreak, "is a reminder to parents to get their children immunized."
And looking back, he recalls too well the kids he saw hospitalized with the disease.
"They were pretty ill kids, and I always remember the few with encephalitis that I saw who ended up with epilepsy and other disorders," he says.
"And the few who died, I can remember as well."