Mandatory quarantine is first established for all incoming ships and trade caravans in the Adriatic port city of Ragusa (modern-day Dubrovnik) in order to screen incoming travelers for signs of being infected with the plague. Venice, which began tracking the spread of the plague as early as 1348, and other cities soon follow. The "word 'quarantine' originates in the Italian term quaranta giorni, or forty days, the length of time suspected plague cases (and travelers) were isolated" (Drago, 2020).