Nowadays, " quarantine " means a period of isolation, of variable duration, applied as a precautionary measure in the case of particularly contagious diseases.
The origin of this practice originated with the advent of the black plague . According to an original document dated 1377, in fact, the ships arriving in the city of Ragusa (Dubrovnik) were forced to stay 30 days off the port before they could disembark, waiting to see if the symptoms of the disease could appear in the crew.
Around the same time, Venice also issued a series of measures to stem the spread of the plague: the isolation was extended to 40 days and was called by the Venetian authorities "quarantena" (in Italian: forty).
After this time, in fact, it was believed that a person suffering from plague was no longer contagious. In reality, the disease was spread by rodent fleas and this preventive measure against the disease was useless.
Before and after the plague, other diseases lent themselves to quarantine, such as leprosy, syphilis, yellow fever and cholera.
