they knew that the only way to control it was quarantine even if that meant whole towns or villages by force of arms, separate well from sick people, etc. And they didn't even know what a germ or a virus was back then and normally looked to God and prayers for restoring health without any practical knowledge of medicine since it was considered witchcraft.
Btw, the Black Plague was the same bug as the Red Plague and happened at the same time. The "black" was when people became infected and got big dark colored painful boils on their bodies, called boboes, under the arms, neck, inner thighs - all the lymph nodes. They'd sometimes get as a big as an orange and eventually burst leaking blood and pus and smelled rank. This was the bubonic version of the plague which was what most people got.
The Red Death, or Red Plague occurred at the same time - same bug just different in symptoms depending on how one became infected (which was more usually the Black). The Red version is the pneumonic version that affected the respiratory system, and people leaked blood from the mouth and nose and coughed up great gobs of blood. Most people infected got the Black version which many survived, but no one seemed to survive the Red (the pneumonic version).
Though there were several times plague broke out in various places the worst time by far was mid-14th century and effected great swaths of Europe with people dying like flies everywhere. It also decimated the church since it was largely priests, monks and nuns doing the work of caring for the sick and using the local churches and cathedrals as makeshift hospitals. The plague was also called the Black Death, the Red Death, the Great Mortality or the Pestilence.
It was this plague that caused such a crisis of available laborers in England which led to the signing of the Magna Carta (though King John immediately broke the agreement). The shortage of laborers because of so much death from the plague meant that following the outbreak any laborer could command almost any price for their work skilled or unskilled. This of course, had land owners up in arms, but the power of the labor force gave them the opportunity to make demands on the Crown.
This worst of the medieval plague was what I thought of immediately when I read that people in West Africa were just tossing out their dead relatives on the street. In the worst infected areas during the plague of the mid-14th century that's also what people did. Dead bodies were dumped out of windows and doors to pile up in the street.
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