In human history, the spread of infectious diseases to mass numbers of people is not uncommon. Pandemics, historians say, started when we humans began farming land and living in communities. Pandemics increased as trade between communities and nations increased.

From smallpox to influenza to the plague, there was often no medical treatment to prevent or cure these diseases. Take for example, the plague that hit Europe in the 14th century. It is also known as the “Black Death.”

With no medical prevention available, isolating the sick was the only effective public health defense. With many other pandemics, the best chance at prevention was to keep sick people away from healthy people. This is called a quarantine. And that is our word for today.

Word experts at Merriam-Webster explain that the word “quarantine” has both French and Italian influences.

In the late 1400s, English speakers borrowed the French word quarantaine which means “a period of about 40 days.” Quarante is the word for the number 40 (forty) in French.

At that time, quarantaine had a religious meaning. Some word experts say it refers to the period of time Jesus spent fasting -- going without food -- in the desert.

However, over time, people began using it for more than just religious situations. For example, it referred to the delay of putting a legal agreement in place. In the early 1500s, quarantine also was used to describe a "period of 40 days in which a widow has the right to remain in her dead husband's house.”

Around the same time, other city-states in Europe were also using a similar word -- quarantena. This word was used to mean the “isolation of a ship to protect the port city from potential disease.”

The Centers for Disease Control and Prevention explains on its website that “quarantine was first introduced in 1377 on Croatia’s Dalmatian Coast.”

By the 1600s, English speakers began using quarantena to mean “isolation as protection from disease.” As the French form of this word (quarantaine) was already being used, English kept it but gave it a new meaning. It was now an English word based on French spelling -- with an Italian definition and Latin roots.

In North America in the late 1600s, quarantine was introduced to control yellow fever. The CDC says this was the case in New York (1688) and in Boston (1691).

That’s the word history. Now, let’s talk about how to use “quarantine” in a sentence. For starters, it is both a noun and a verb.

As a noun, we often use it after the preposition “under.” If someone is under quarantine, they are required to physically keep away from others. For example: “When she was under quarantine, the woman learned how to play the piano and speak simple Russian.”

The word “quarantine” is often combined with other nouns. In the news and from government announcements you may read about, quarantine guidelines, quarantine authority and quarantine systems.

As a verb, we can say that some young people in the United States are not fully self-quarantining themselves.

So, isolation and quarantine are both ways to help protect the public. They both prevent exposure to people who have or may have a contagious disease.