POLIOMYELITIS

A MYSTERIOUS ENEMY VANQUISHED

Not long ago, polio — short for poliomyelitis — was one of the most feared diseases on the planet. Highly infectious, it does not usually have visible symptoms, and about three quarters of sufferers recover in a few days. In the other one quarter of victims, though, the poliovirus can turn deadly, attacking the spinal cord.

Victims can develop meningitis and paralysis, which in turn lead to death in as many as ten per cent of those stricken, when their breathing and swallowing muscles are weakened or paralyzed. The only treatment was the iron lung, developed in the late 1920s, which forced air in and out of the lungs. Before the advent of vaccines in the mid-1950s, polio was a terrifyingly common and indiscriminate scourge.

Polio epidemics first emerged during the late nineteenth century and worsened through the first half of the twentieth, ironically because of improving public health standards limiting what had been all but universal circulation of the poliovirus among infants. By the late 1940s, polio was the middle- class plague, mostly striking otherwise healthy children as well as increasing numbers of adults, particularly in new postwar suburbs.

Polio epidemics peaked in Canada in 1953 with some nine thousand cases and five hundred deaths. Much remained mysterious and uniquely frightening about polio during the late 1940s. With epidemics typically starting during the summer “polio season,” the popular and scientific view of “the crippler” as a warmweather threat was reinforced in North America.

Widespread immunization programs started in 1955 with the vaccine developed by Dr. Jonas Salk and changed everything. The last polio case in Canada was in the 1970s, and the country was certified polio-free in 1994. Worldwide incidence has declined ninety- nine per cent since 1988. Polio remains active only in Pakistan and Afghanistan, according to the World Health Organization.