No, polio was never vanquished. It’s still around, as always. It’s just called different names now. Surprise! And when they can’t manage to come up with a weird-sounding name, they just refer to it as “polio-like.” It’s a neat little hat trick. There are many ways to perform this trick. Here’s a simple example…
Note how in the article (click link above), it is referred to as “Acute Flaccid Myelitis,” or AFM. Well, in other articles about the very same thing, it is also referred to as “Acute Flaccid Paralysis,” or AFP. It’s the same “mysterious polio-like illness.” It happened precisely the same way during the first half of the 20th century. For a long time, polio was referred to as polio or poliomyelitis or infant paralysis or childhood paralysis, etc.
Here’s a more comprehensive list of conditions which can produce polio-like paralysis:
Arsenic Poisoning; Bilious Remittent Fever; Chinese Paralytic Syndrome; Cholera Morbus virus; Coxsackie virus; DDT Poisoning; ECHO; Enteroviral Encephalopathy; Epidemic Cholera; Ergotism; Famine Fever; Guillain-Barré Syndrome; Hand, Foot, and Mouth Disease; Inhibitory Palsy; Intermittent Fever; Lead Poisoning; Myalgic Encephalomyelitis (Chronic Fatigue Syndrome); Post-Polio Syndrome; Reye’s Syndrome; Spinal Apoplexy; Spinal Meningitis; Transverse Myelitis; Traumatic Neuritis; Undiagnosed Congenital Syphilis; Viral or Aseptic Meningitis; Worm Fever… and “provocation of limb paralysis by intramuscular injections of many types, including a variety of vaccines.”
At one point, the scientific community identified what it believed was a virus that caused polio. They called it the “poliovirus.” If you displayed symptoms of paralysis in a person and that person tested positive for the poliovirus, he/she was said to have “polio.” If another person displayed exactly the same symptoms but tested negative for poliovirus, he/she was declared “polio free.”
Get how the word game is played?
For further related reading, see Marco Cáceres on Polio