The History Of Quarantine: How Individual Actions Stopped Our Biggest Threats

With many cities, states, and even countries issuing "stay at home" orders to stop the spread of COVID-19, now might be a good time to look back through history at just what exactly quarantine is, where it came from, and how successful quarantine has proven in the past.

Plague doctor mask. (Getty Images)

Quarantine Through The Ages

Yersinia pestis, A.K.A. the Black Death or bubonic plague, is a bacterium that spread throughout Europe during the mid- and late-1300s, killing over 30% of the entire continent. Within a few days of exposure, a victim of the bubonic plague experienced high fevers, body aches, and nausea that sometimes resulted in vomiting blood while the lymph nodes (those things that help fight off infections) of their necks, armpits, and groins swelled massively. Once the infection reached the blood, body parts began to die off, and the victim's skin turned black. Overall, not a fun or pretty way to go.

The bacterial infection was spread by the bite of fleas, which often resided on the rats that swarmed city streets and kept second homes in the well-stocked underbellies of merchant ships. Since rodents have no idea of their own consciousness, let alone the concept of self-isolation, they spread the bacterium all across Europe on their globetrotting adventures. Unfortunately, medieval Europeans—who were considerably more self-aware but roughly equally knowledgeable about germ theory—never got a clear understanding of how the plague manifested, either.

The people of Venice, however, did land on something at least marginally useful. As the Venetians controlled many points of entry for merchant ships, they decided to stop all ships at the ports and isolate them for 40 days before allowing them onto the shore. The Italian word quarantino, derived from the word for the number 40, eventually morphed into the English "quarantine" as the practice became popular throughout Europe. Although the Plague was already spreading, most historians believe the Venetian quarantine was beneficial.