Where does the word quarantine come from, and what did Venice do?

The word quarantine comes from medieval Latin and Italian terms for the number forty. It became attached to disease through the practice of making ships from plague-affected ports wait about forty days before landing. Venice is the city most closely linked to the practice, and it developed a permanent, government-run system of isolation islands, though the earliest recorded formal rule is from Ragusa. [1] [2]

According to wordorigins.org, medieval Latin quarentena varies the classical Latin word for forty. From the twelfth century it covered several measurements involving forty, such as a furlong of forty rods, or a period of forty days in religious, legal or diplomatic settings. Its first recorded English use, around 1470, referred to the wilderness where Christ fasted. The disease sense probably reached English through Italian and appears by 1649. [1]

The history walks site on Venetian language adds a point about wording. Venetian officials themselves did not use the word quarantine but contumacia, meaning isolation. Quarantina, a diminutive of quaranta, meant roughly forty-odd, so people were kept in isolation for a quarantina di giorni, forty-odd days. [3]

Venice was a trading hub and especially exposed to plague. SAPIENS reports that in 1423 the government set up the island later called Lazzaretto Vecchio to house plague victims, and in 1468 a decree turned a second island, formerly a monastery, into Lazzaretto Nuovo. Nuovo held warehouses and more than 100 rooms where crews waited before entering the city, while goods were aired and cleared with smoke from aromatic herbs and saltwater, and handlers washed their hands with vinegar. [4] [5]

SAPIENS describes the system as permanent and government-run, with hundreds of officials, and says it lasted until Napoleon's conquest in 1797. It replaced earlier care that had been left to charity and religious orders. The system had limits: officials could not check every smuggler or caravan, and they did not understand the time between exposure and symptoms. [4]

The forty-day length was not fixed at first. Periods ranged from twenty to over fifty days, and a galleon crew in 1593 spent fifty-three days in isolation. One source says Venetians settled on about forty as they gained experience and judged it enough to be sure a person was not carrying plague. [3]

Sources differ on the origin of the number and on priority. The medical journal Etymologia notes that in 1377 the Great Council of Ragusa (modern Dubrovnik) set a 30-day separation, the trentino, for visitors from plague areas, and that later it was extended to forty days. It suggests the longer period may have been more effective, or may nod to biblical forty-day events such as the Flood or Jesus's fast. Wordorigins.org instead places the disease sense in Venice in the early fourteenth century. These accounts do not agree on dates. [2] [1]

Mark Harrison, a historian of medicine at Oxford, says it is unclear where the forty days came from, and that a biblical reference is one possibility. The sources reviewed therefore do not settle whether the number was religious, practical, or both. [6]