With everyone around the world still struggling with the COVID-19 pandemic, we thought we’d take a look at a famous historical pandemic that never actually went away. 

Of course, we’re talking about the plague! Better known as the Bubonic Plague, “The Black Death,”  and “The Pestilence,” it has been around for centuries. And, if you want to know more about it (and how to prevent it) here’s a quick look at the major plague outbreaks in history, as well as its symptoms, treatment, and precautions.  

See if you spot any similarities with the current pandemic, and if nothing else, it will be a great reminder about how far we’ve come since those times!

While nowadays we call almost any widespread disease a plague, it actually refers to a very specific infectious disease. The plague is caused by the bacillus Yersinia pestis. This leads to a serious infection of the lymphatic system, which is basically a network of vessels and other tissues that maintain the body’s fluid balance and fight off any infections.  

Y. pestis is a bacterium that spreads via infected fleas or animals, like rodents, squirrels, or hares. It can then be passed to humans who are bitten or scratched.  

This bacteria that causes the plague was discovered in 1894, and people soon developed ways of treating and preventing its spread.

• The plague is caused by a bacterium known as Yersinia pestis (or Y. pestis, for short).  
• This bacteria is usually found in small mammals (like rats) and fleas from these animals, and it’s transmitted to humans by flea bites. It is also transmissible from person to person when it is the pneumonic form. 
• Infected fleas and rats often spread the plague over long distances, especially on trading ships. It was also carried by humans travelling abroad, and infested grains, clothing, and other goods!  
• Because it’s an animal disease, plague is found all over the world (actually in all the continents except Oceania).

While anyone who has the plague is infected by the bacterium Yersinia pestis, there are three main forms of plague infections: bubonic, pneumonic, and septicemic.

Bubonic Plague

This is the most common form, and it is when the bacteria spread to the person’s lymph nodes, which swell up into something called “buboes.”

Pneumonic Plague

In the more severe pneumonic form, the same bacteria causes an infection in the lungs (and symptoms like shortness of breath, cough, and chest pain can happen)

Septicemic Plague

While in the rarer septicemic forms, the bacteria enters the blood causing clots. Hence people’s hands and feet may turn black, because the tissues have died.

Throughout history, people thought that the plague was spread by rats. While this is absolutely true, it can also be spread by:

There have been many bubonic plague epidemics throughout history, though most of them have been a part of one of the three great world pandemics that started in 541, 1347, and 1894. Each of them had devastating effects causing the deaths of thousands of people and animals across many nations and continents. 

Of course, there were plagues before and after these, and the most famous plague outbreaks in history are:

The First Plague Pandemic

• It started with the Plague of Justinian (541–549 AD), named after an emperor at the time, and it spread to Asia, Africa, and Europe.
• Then the bubonic plague pandemic continued to recur until the middle of the 8th century and spread throughout the Mediterranean region from Naples.

The Second Plague Pandemic

• The bubonic plague came back again as a major outbreak in the 14th century.
• It seems that it originated in Central Asia.
• The first and worst occurrence was the Black Death (1346–1353) that spread throughout the known world at the time due to trading ships.
• The Black Death is when people started public health measures like isolating sick people, quarantines, and doctors wearing protective clothing!
• There were also major epidemics in the 1600s in China, Naples, and London.

The Third Plague Pandemic

• There were numerous occurrences of the bubonic plague starting in Yunnan, China, in 1855.  
• This spread worldwide until 1912, but most of the outbreaks were in China and India.  
• It led to more than 15 million deaths, and about 10 million died in India alone.

• Many outbreaks of bubonic plague and pneumonic plague came and went around the world, but especially in Europe, until the 19th century.   
• Since the plague bacteria (Y. Pestis) doesn’t survive well in sunlight, these outbreaks would also slowly die out in the hotter months. 
• Eventually, with the development of antibiotics such as streptomycin and public health measures such as quarantine, a lot had been done to reduce the recurrence of the pandemic plague. 
• Currently, there are only around 2,000 cases each year (mostly in Africa, Asia, and South America), and the fatality rate has dropped to 5-15%.
• As bubonic and septicemic plagues can’t be passed from person to person, (and even with pneumonic plague, human-to-human transmission requires direct contact), it became easier and easier to take preventive measures against rats and fleas.

Unfortunately, all the forms of the plague (especially the bubonic plague) never really went away. But luckily, the disease isn’t nearly as deadly as it once was, thanks to antibiotics. 

There hasn’t been a widespread epidemic of the plague since the 17th century. This is because we now know how this disease is transmitted, how to prevent it, and how to treat it, and even how to prevent people who may have been exposed to the bacteria from getting sick!  

When there were some cases of both bubonic and pneumonic plague diagnosed in China in July 2020, it was quickly dealt with. So, we may never have to face the infamous bubonic plague spreading across the globe again! [2]

The plague can cause a range of general symptoms such as fever and chills, headaches, sweating, nausea, bleeding, and eventually organ failure. 

Apart from these, the symptoms will be different based on the type of plague the person has. For example, with bubonic plague, you might experience swollen lymph nodes and open sores, while if it is the pneumatic version, you might face coughing and a parched throat.

• Luckily today, there is a treatment for all the forms of the plague, including treatments for bubonic plague and pneumonic plague, and the plague is now curable in most cases. 
• When people with plague symptoms are diagnosed early, they are usually treated with antibiotics (since it is caused by a bacterium) and can be fully cured! 
• But, if it is left untreated, pneumonic plague can be fatal within 18 to 24 hours, while the bubonic plague, if it kills, will do it within 10 days. [1]

• If you are worried about the plague, you need not be! It’s relatively easy to take lots of preventive measures against the plague. 
• This includes things like: 
  • Precautions against flea bites, by using repellent sprays during activities such as camping, hiking, or working outdoors, and keeping fleas off of your pets with flea control products.
  • Avoiding animal carcasses, and wearing gloves if you have to handle them.
  • Make sure your home and surroundings are free of rodents.
  • Avoid any direct contact with infected materials like bed sheets or clothes of those who have the disease. Instead, use gloves, etc.  
• While there is a vaccine against the bubonic plague, the WHO usually saves it for high-risk groups (like laboratory personnel and healthcare workers).