Polio Returns after Nearly Being Eradicated

centuries-old virus stages a comeback

By Jonny Lupsha, Wondrium Staff Writer

Once again, the polio virus is spreading around the globe. Until this year, Pakistan and Afghanistan were the only two nations still reporting cases. Polio was identified in the 1930s and two vaccines were developed in the 1950s.

Polio vaccine upclose on syringe
In the early 1950s, the first of two polio vaccines, the inactivated poliovirus vaccine (IPV) or Salk vaccine, was developed. Photo by Tobias Arhelger / Shutterstock

Last year, only Pakistan and Afghanistan reported any incidents of patients contracting polio. Beginning in February, however, cases of polio were reported in Malawi and Israel, as well as both Pakistan and Afghanistan. Great Britain detected the virus in its sewage in June. Earlier this month, New York City did, as well.

This unhappy news comes in spite of decades of work to eradicate the polio virus from the Earth. In his video series An Introduction to Infectious Diseases, Dr. Barry Fox, Clinical Professor of Infectious Disease at the University of Wisconsin School of Medicine and Public Health, recounts the history of the polio virus.

Centuries of Havoc

The first recorded outbreak of poliomyelitis in the United States was in 1894, spreading quickly over the next several decades. The virus killed 27,000 Americans in the summer of 1916 and eventually, in 1921, infected Franklin Delano Roosevelt. All this happened before the virus was identified, which finally occurred under an electron microscope in the 1930s.

It was far from a new virus.

“Polio was first described in medical literature several hundred years ago, and polio is actually an intestinal virus infection,” Dr. Fox said. “It is spread person to person through contact with fecal waste, unwashed hands, shared objects, and contaminated food and water. Polio enters the body through the mouth, travels into the digestive tract, and is eventually excreted.”

However, the main part of the body in which polio multiplies is the small intestine. In the majority of cases, people are asymptomatic or they just experience minor headaches or nausea. Tragically, in some cases, polio travels through the bloodstream to the brain or the spinal cord, destroying nerve cells called motor neurons, which are responsible for the muscles contracting.

This is why polio victims sometimes suffer muscle wasting and paralysis.

Modern Polio

“There was an intense effort to develop a vaccine against polio,” Dr. Fox said. “In 1953, just after an epidemic year where 58,000 new cases of polio were reported, an American medical researcher, Dr. Jonas Salk, announced on radio that he had successfully tested a polio vaccine from killed virus strains—he even tested it on himself and his family.

“Now, after conducting clinical trials on over 2 million schoolchildren, the vaccine was deemed safe and effective.”

In 1957, the first year the vaccination was widely distributed, polio cases dropped by 90% in the United States, to just 6,000. Another scientist, Albert Sabin, developed an oral vaccine against polio, which contained live, weakened samples of the virus so that the immune system could be enhanced to easily defeat infections. He tested his vaccine in the Soviet Union in 1959 and his vaccine eventually overtook Salk’s globally.

“Both scientists donated the rights to their vaccines, unpatented, as gifts to humanity,” Dr. Fox said. “In 1987, the World Health Organization launched a global initiative to eradicate polio from the planet within 15 years. By the year 2000, there were fewer than 2,000 cases worldwide.”

Part of the trouble with fully eradicating polio, according to Dr. Fox, is that in some countries—especially war-torn countries—people are hard to reach or they outright refuse vaccination.

An Introduction to Infectious Diseases is now available to stream on Wondrium.

Edited by Angela Shoemaker, Wondrium Daily