3. Polio
Poliomyelitis is a dangerous disease caused by the poliovirus. This can be easily spread by someone who has ingested infected feces or had contact with infected saliva (in rare cases). Plenty of people infected with this didn’t have symptoms, but roughly a quarter of them experienced mild flu-like symptoms.
The first epidemic of polio in the United States emerged in 1894, and there were still some causes popping up during the first half of the 20th century. This virus had a major impact on the US and public health and was the most popular case of President Franklin Delano Roosevelt. This virus was eliminated from our country in 1994, and scientists are still working on helping third-world countries get rid of it as well.
