No matter where you look up the meaning of the word “plague”, it’s never a good thing. It can be confusing, because as a verb, plague means “to cause continual distress”, yet as a noun, it means a deadly disease that spreads very quickly – what we would today call a “pandemic”. It can also refer to one specific disease, Yersinia pestis.
On top of that, a plague can refer to a large number of insects or animals in one place that are causing a lot of damage, like the locusts currently swarming in east Africa.
In this article, we’ll talk about the plagues, or pandemics, that humans have battled with throughout history.
The worst plague in history was the Black Death, which may have killed up to 200 million people. This was caused by a bacteria, Yersinia pestis, that first hit Europe in the 1340s.
People still disagree over where it came from, but the most common theory is that it first emerged in Asia, in a certain type of flea that lived on rats. In fact, when scientists in the 1900s were looking for the cause of a similar disease, they came to Hong Kong as part of their investigation.
Back in the 1300s, life was pretty dirty, as people didn’t know anything about hygiene. They also didn’t have much medical knowledge – they had never heard of antibiotics or quarantine. This meant that the plague killed around 90 per cent of the people it infected, and in some cases, it killed everyone it infected. But this didn’t wipe it out.
Two more deadly waves of the plague hit in the 1500s and 1800s. In fact, scientists think that it may have been around before the 1300s, as there are records of a similar disease in Rome in 146AD, known as the Justinian plague.
The symptoms of the plague were awful. It started with a swelling in the lymph nodes under the armpit or in the groin, until they were about the size of an apple. Once the swellings burst, people had a fever, vomited blood, and soon died.
After the devastation of the first world war came the Spanish flu. It did not actually come from Spain, but this was where it first became bad enough to be noticed. It killed up to 40 million people – more than all the deaths of the first world war. It spread across the world, aided by the movement of hundreds of thousands of soldiers to far-off battlefields.
It started out like a normal cold, so people were not too worried about it. But then those who were infected developed pneumonia, a lung condition which makes breathing difficult. After that, victims eventually suffocated.
No one knows where the Spanish flu started, but recent studies show that the virus may have emerged when strains of pig and human flu infected the same host, and their genes combined to create a new mutation.
There is no doubt that plagues changed the course of history. They caused empires to fall and new ones to arise. Smallpox first emerged around 68,000 years ago. We have no idea how many people it has killed, but we do that in the 20th century alone it killed around 500 million people.
Smallpox was introduced to the Americas by European colonisers in the 1400s. It was responsible for the fall of the Aztec and Incan empires, and killed up to 90 per cent of the Northern Native American population – allowing the Europeans to steal the land and claim it as their own.
Smallpox was the leading cause of death in the 18th century. And, like all good plagues, it was awful, causing sufferers to break out in small blisters all over their bodies that caused them great pain.
People did notice, however, that once someone had survived smallpox, they never got it again. So, in the 10th century, people in China began taking some pus from the infected blisters and scratching it into their own skin. This allowed the body to learn the virus’ code and build immunity to defeat it. In 1798, an British doctor, Edward Jenner, developed a vaccine. In 1966, the World Health Organisation began a global vaccination campaign to wipe out smallpox for good. The last-ever case was diagnosed in 1977. Smallpox is one of only two infectious diseases to have been completely stopped. Hooray for vaccines!