For most Canadians, especially young adults, poliovirus is at best a historical fact that has no relevance to their lives. They probably don’t even know what it is, or how it affects the body. They certainly don’t worry about becoming infected.
Poliomyelitis is a highly infectious viral disease that spreads from person to person and can invade an infected person’s brain and spinal cord leading to paralysis. The disease mainly affects children under five but even those who seem to fully recover may develop new symptoms or paralysis as adults 15 to 40 years later. This is called post-polio syndrome. There is no cure for polio, it can only be prevented. Since its introduction in the mid-1950s, polio vaccine has saved millions of children.
Polio was first clinically identified in the late 18th Century but it was not until 1953 that Dr. Jonas Salk developed a potentially safe vaccine. It was a life-changer – 76,000 cases of paralytic polio were reported in Canada, the US, the Soviet Union, Western Europe, Australia and New Zealand in 1955. By 1967, the number of cases had dropped to 1,013 in those countries. The decrease by some 75,000 cases was the direct result of only 12 years of vaccinations.
In 1991, poliovirus was declared eradicated from the entire Western Hemisphere. But in 1988 there were still an estimated 350,000 cases around the world. This would drop to only 416 by 2013. By 2014, the success of the global effort to eradicate the disease led to there being only three countries that remained polio-endemic: Afghanistan, Nigeria and Pakistan. And in September 2015, the World Health Organization announced that Nigeria had eradicated polio, leaving just two countries where it remains.
Because polio cannot be cured, prevention remains the only option. Fortunately, the polio vaccine has proved extremely successful. Education has also been important in the battle to rid the world of the scourge of polio. Polio was one of the most feared and devastating diseases of the 20th Century and it still devastates children and families today. We may doubt the chances of becoming infected, but our world is much ‘smaller’ than it was even 50 years ago as travel brings everything, and everyone, closer.
Polio remains incurable, extremely contagious and life-altering disease and make no mistake, without the vaccine, millions would have died or suffered its effects. Polio is also a wonderful example of the success of vaccines that can prevent disease — can we be as successful with others?
Written by Dr. Paul Martiquet, Medical Health Officer for Rural Vancouver Coastal Health including Powell River, the Sunshine Coast, Sea-to-Sky, Bella Bella and Bella Coola.