November 23, 2020History of Medicine
There are three wild types of poliovirus (WPV) - type 1, type 2, and type 3. Type 2 WPV was declared eradicated in September 2015, with the last virus detected in India in 1999. Type 3 WPV was last detected in November 2012 and was declared eradicated in October 2019. Only type 1 WPV has not yet been eradicated.
Most of us think that the polio epidemic was only in the US in the 1950s, but the polio virus is as old as the ancient Egyptians, if not older. Ancient Egyptian paintings and carvings depict otherwise healthy people with withered limbs, and children walking with canes at a young age. It is theorized that the Roman Emperor Claudius was stricken as a child, and this caused him to walk with a limp for the rest of his life. Perhaps the earliest recorded case of poliomyelitis is that of Sir Walter Scott. In 1773, Scott was said to have developed "a severe teething fever which deprived him of the power of his right leg". At the time, polio was not recognized as a named disease.
Polio in the United States
Polio first emerged in the United States in 1894. However, the first large epidemic occurred in 1916 when there were 27,000 cases and 6,000 deaths, with roughly a third in New York City. Symptoms of polio included common flu-like symptoms such as sore throat, fever, tiredness, headache, a stiff neck and stomach-ache. Unfortunately for a few, polio affected the brain and spinal cord, which led to meningitis. When this occurred, approximately 1/200 patients became paralyzed, with death occurring in approximately 20% of those suffering paralysis.
After World War II, Americans doused their neighborhoods, homes and children with the highly toxic pesticide DDT in the hope of eradicating polio. Yet, the number of cases grew larger each season with 25,000 cases in 1946, as many as in 1916, and the number grew almost every year up to its peak of 52,000 in 1952. In the 1950's, as the poliovirus pandemic terrified society, cities closed pools, swimming holes, movie theaters, schools and churches, forcing religious ceremonies to be on local radio.
It was only 60 years later that a vaccine was developed, and in 1955, after a massive clinical trial in which 1.8 million school children were injected with either the polio vaccine or a placebo, the Salk vaccine was declared safe and effective. Between 1955 and 1961, the Sabin oral poliovirus vaccine (OPV) was tested on at least 100 million people in the USSR, parts of Eastern Europe, Singapore, Mexico, and the Netherlands. The Sabin OPV for use against type 1 WPV, was licensed in the US in 1961. Sabin's vaccines for type 2 and type 3 polioviruses were licensed in 1962, and since 1979, no cases of polio have originated in the U.S. The last time the poliovirus was brought into the US by a traveler occurred in 1993.