One of the most devastating pandemics in human history, peaking in Europe between 1348-1350.
Killed 25 million people, 30-60% of Europe’s population.
Spread by infected rats and flea bites.
Started with appearance of buboes (tender, enlarged lymph nodes under the armpits, in the neck, or in the groin).
Most died a horrific death within 3-5 days.
The Adriatic port city of Ragusa (modern-day Dubrovnik [in Croatia]) was the first to pass legislation requiring the mandatory quarantine of all incoming ships and trade caravans in order to screen for infection [during the Black Death]...some medical historians consider Ragusa’s quarantine edict one of the highest achievements of medieval medicine. By ordering the isolation of healthy sailors and traders for 30 days, Ragusan officials showed a remarkable understanding of incubation periods. New arrivals might not have exhibited symptoms of the plague, but they would be held long enough to determine if they were in fact disease-free.
...The 30-day period stipulated in the 1377 quarantine order was known in Italian as a trentino, but Stevens Crawshaw says that doctors and officials also had the authority to impose shorter or longer stays. The English word “quarantine” is a direct descendent of quarantino, the Italian word for a 40-day period.
Why 40 days? Health officials may have prescribed a 40-day quarantine because the number had great symbolic and religious significance to medieval Christians. When God flooded the Earth, it rained for 40 days and 40 nights, and Jesus fasted in the wilderness for 40 days.
Stevens Crawshaw says that even before the arrival of the plague, the biblical notion of a 40-day period of purification had crossed over into health practices. After childbirth, for example, a new mother was expected to rest for 40 days.