The Black Death

The Black Death was a devastating pandemic in the middle of the 14th century that claimed 25 million lives in just 4 years. Caused by the bubonic plague, it first arrived in Europe in 1347 and it would eventually kill as much as one third of the continent’s population. The plague was suspected to have originated in China over 2,000 years ago and spread through trade routes in India, Persia, and Egypt.

The time of the Black Death was one of chaos, when healthy people did all they could to avoid the sick, with some doctors refusing to see patients, shopkeepers closing stores, and priests declining to administer rites. In the panic, many people fled cities for the countryside, but the disease was inescapable, affecting many common animals as well as people.

The plague attacked the lymphatic system. Those infected with the disease suffered from severe headaches, fevers, and most notably, one or more swollen lymph nodes. Victims often developed a gruesome appearance, with black boils along the body covered in blood or pus.

The Black Death was so fearsome mainly as a result of being extremely contagious: simply making contact through clothing or breathing the same air could risk transmission. The disease was also extremely efficient: those who were healthy at night could rapidly develop symptoms and be dead by morning.

Today, scientists have discovered that the Black Death was spread by a bacteria called Yersinia pestis, which was discovered towards the end of the 19th century. Bites from infected fleas and rats, both of which could be found nearly everywhere in medieval Europe, were a major source of the bacteria. They were particularly common aboard ships, which explains how the plague traveled from one port city to another.

In the middle of the 14th century, however, there seemed to be no rational explanations as to why so many people were dying. The spread of the plague and its prevention were mysteries to the doctors of the time, who believed that a spirit from an infected person escaped from their eyes and flew into somebody nearby, killing them.

To treat their patients, many physicians used improvised techniques that were sometimes dangerous, such as bloodletting, burning herbs, and using rosewater or vinegar in bathwater.

Many cities were eventually able to slow the spread of the plague by isolating arriving sailors until they were proven not to be carrying the disease. At first, they were held on their ships for a period 30 days (a trentino), a period that was later increased to 40 days, or a quaranto - this was the the origin of the term quarantine, which is still used today.

Despite these efforts, the plague never quite disappeared and returned again years later to wreak havoc on Europe. For centuries, the plague made an appearance every few generations. Even today, the plague still exists: it is very rare, but according to the WHO, there are 1000 to 3000 cases every year. However, advances in public health and modern sanitation practices have greatly diminished the impact of the disease.