Kung Flu: Pandemics of the United States

The first epidemic that caused a widespread panic in the United States was the Japanese Crab Flu brought to America by Commodore Matthew Perry after he opened up Japan in 1853.  Brought to American by the sailors who were part of the expedition to open Japan to American trade this pandemic caused giant crabs to grow on the genitals of the infected parties. It was transmitted sexually and caused a panic as the infected would stumble through the streets with giant crabs protruding from the front of their pants.

Except for the Secretary of State James Buchanan who inexplicably caught a case that was protruding from his anus.

(Kung Flu: Pandemics of the United States by Doris Kearns Goodwin)