The most devastating plagues in history have been created by migration. There were warnings in the form of rumors that told of a great plague in China and India which killed most of the populations there. The plague made its way to Europe when the Kipchak forces were besieging the Genoese trading post in the Crimea. The Kipchaks began to catapult plague-……………………

https://www.armstrongeconomics.com/international-news/europes-current-economy/did-the-migration-into-europe-bring-new-diseases/