What caused polio virus in 20th century

Like a horror movie, throughout the first half of the 20th century, the polio virus arrived each summer, striking without warning. No one knew how polio was transmitted or what caused it. There were wild theories that the virus spread from imported bananas or stray cats. There was no known cure or vaccine.

Explanation:

1894, first outbreak of polio in epidemic form in the U.S. occurs in Vermont, with 132 cases. 1908, Karl Landsteiner and Erwin Popper identify a virus as the cause of polio by transmitting the disease to a monkey.

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recent news about two years ago indicates that a polish forestry student by chance unearthed at a depth of about 40cm (16 inches), during digging in a damp polish forest he found a 13-page manuscript into a thermos flask.

greek jew marcel nadjari was a aischwitz slave who witnessed how the nazi's built big death chambers and crematoriums and told how he was forced to escort fellow jews to the gas chambers. he accounts on this manuscript how the nazi's disguised this chambers to look like showers. also, he describes this place as a process of extermination from the chambers to the trains arriving to take the bodies.

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