In late 1949, things were looking bleak for Chiang Kai-shek and his Nationalist forces. Two million Nationalists had just fled from the Chinese mainland to Taiwan, and now the Communists looked poised to invade the island. Despite the fact that Communist forces had experience with amphibious operations and that a Communist invasion of Taiwan would likely have been successful, the operation never happened. What was the reason for Taiwan’s salvation? According to one source [gated], it was a waterborne parasite: schistosoma japonicum.
Lacking proper landing boats, Communist military leaders knew they would have to rely on junks to ferry soldiers across the Taiwan Strait. However, without access to proper port facilities in Taiwan the junks would not be able to get close enough to shore to disembark their troops directly onto dry land. The Communists’ solution was simple: the troops would swim from the junks to the invasion beaches. To prepare for their swim, soldiers of the invasion force were given months of swimming lessons in canals on the mainland.
However, unbeknownst to invasion planners, the canals were infested with schistosoma japonicum parasites. Soldiers started to get sick soon after the lessons began. Eventually, an estimated 30,000 to 50,000 Communist soldiers came down with schistosomiasis and were in no condition to participate in the operation. This represented the core of the invasion force. The outbreak delayed the invasion six months and before the Communists could mount a new operation the Korean War began and American warships positioned themselves in the strait. The window of opportunity had closed.
Source: Kiernan Jr, F. A. 1959. “The blood fluke that saved Formosa.” Harpers Magazine: 45–47.
Special thanks to Jonathan Shainin for obtaining a copy of the above Harper’s article.
