Pandemics are endemic in human history
From the Plague of Athens 2,500 years ago to the current coronavirus outbreak, disease is always spread by people travelling from one place to anotherSvetoslav Stefanov
Man and disease go hand in hand from the very early steps of human civilisation. Excavations in many Neolithic settlements across the globe reveal signs of devastating epidemics, sometimes resulting in abandoning the village altogether, or the decimation of its entire population. Yet, few epidemics turned to become pandemics raging so wildly that the final outcome was a significant change of the history of mankind.
The first recorded pandemic was the so-called Plague of Athens, which devastated the city-state of Athens in 430 BC, a year after the start of the Peloponnesian War, killing up to 100,000 people and helping Sparta to finally win the war. The plague is believed to have entered Athens through the port city of Piraeus, its main source of food and supplies, after passing through much of the eastern Mediterranean.
The plague is described by historian and politician Thucydides, who himself fell ill but survived. In History of the Peloponnesian War he writes of a disease coming from Ethiopia and passing through Egypt and Libya into the Greek world and spreading throughout the wider Mediterranean. The plague was so severe and deadly, and physicians were so helpless that they were the first to die after their contacts with the sick. In overcrowded and besieged Athens, the disease killed an estimated 25% of its population.
The plague returned twice more, in 429 BC and in the winter of 427/426 BC, and further incapacitated the city-state's war capabilities. The main result was that finally Athens, until then the superpower among the ancient Greek city-states, lost the war and from “first among equals” turned into a secondary one.
Some 30 pathogens have been suggested as having caused the plague, but it was not until mid-1990 when the main cause was revealed. A DNA analysis of remains excavated from a mass grave showed that citizens of ancient Athens were killed by a kind of typhoid fever, until then unknown in Europe.
Almost 600 years had to pass until the civilised world was once again hit by a pandemic. In the mid-2nd century the Roman Empire was enjoying its heyday. It was stretching from the Mideast to nowadays Scotland, with the Mediterranean turned into an inner sea of the empire. Yet, it was not immune. In 165 AD troops returning from campaigns in the Near East brought a disease which caused a pandemic known as the Antonine Plague, or the Plague of Galen.
This one raged until 180 AD and took the lives of up to five million people across the whole empire, or about 25% of the whole population. In 169 AD it claimed the life of Roman Emperor Lucius Verus, who was succeeded by Marcus Aurelius Antoninus whose last name has become associated with the epidemic.
The disease was described by Greco-Roman physician and writer Galen, who was present at the outbreak among troops stationed at Aquileia in the winter of 168/169 AD. He briefly records observations of the epidemic in the treatise Methodus Medendi and describes the plague's symptoms as fever, diarrhoea and pharyngitis, as well as a skin eruption, dry or pustular. The information does not clearly define the nature of the disease, but scholars have generally preferred to diagnose it as smallpox. The main outcome of the pandemic was that the Roman army was devastated, and the gradual decline of the empire started.
Four centuries later, the Roman Empire was not existing any more - its western part had fallen under the barbarian invasions, while its eastern part had reinvented itself into a new entity to be later called Byzantium. In the mid-6th century AD it was ruled by Emperor Justinian and was trying, somewhat successfully, to re-conquer the empire's lost territories along the Mediterranean. But all of a sudden it was struck by a plague that all but stopped that endeavour.
A pandemic, called the Plague of Justinian, started in 541 from the port of Pelusium, near Suez in Egypt, and was brought to the empire's capital, Constantinople, by ships bringing grain and … rats. The plague was described by Byzantine historian Procopius of Caesarea. According to him, at its peak the plague was killing 10,000 people in Constantinople daily. The accuracy of the figure is in question, and the true number will probably never be known, but it is estimated that the plague killed up to 25 million people during the next several years across the whole Mediterranean, and has stopped the resurrection of the Roman Empire under Constantinople. After years of speculations, in 2013, researchers confirmed that the cause of the plague was Yersinia pestis.
This was the bacterium responsible for the most well-known, and at the same time most devastating pandemic, simply called the Black Death. It raged across Europe from 1347 to 1351 and killed an estimated one third to one half of the continent's population. Also known as the Pestilence, the Great Bubonic Plague, or the Great Plague, it resulted in the deaths of an estimated 75 to 200 million people in Europe, or 30% to 60% of the continent's population.
Originating from Central or East Asia, it was most probably brought along the Silk Road by merchants or invading Mongol armies to Crimea in 1340s. From there, fleas living on the black rats that travelled on merchant ships brought it to Italy and spread it throughout the Mediterranean. The bacterium Yersinia pestis results in several forms of plague - septicemic, pneumonic and, the most common, bubonic, namely the latter raged across Europe.
Plague was reportedly first introduced to Europe via Genoese traders from the port city of Kaffa in 1347. During the siege of the city by the Mongol army, which was suffering from the disease, infected corpses were catapulted over the city walls in Kaffa to infect the inhabitants. The Genoese traders fled, taking the plague by ship into Sicily, then the Italian mainland, from where it spread across the continent.
Additional conditions such as war, famine, contagiousness and weather contributed to the severity of the Black Death. According to some estimates, the plague may have reduced the world population from an estimated 475 million to 350-375 million in the 14th century. It took 200 years for Europe's population to recover to its previous level, and some regions only recovered by the 19th century. Outbreaks of the plague recurred until the early 20th century.
And it was namely in the 20th century when the next pandemic appeared. Known popularly as the Spanish flu, it raged from January 1918 to December 1920, infecting up to 500 million people, about a quarter of the world's population at the time, and killing between 25 and 50 million. The flu period coincided with the last year of World War I and the early post-war period, which contributed for the very high mortality.
As in 1918 the war was in its final stage, censors in many states, such as France, the UK and Germany, did their best to minimise the reports of illness and mortality in order to maintain troops' morale, but let media report widely about flu effects in neutral countries. Thus an impression appeared that Spain, where even King Alfonso XIII fell ill, was especially hard hit, and the pandemic got its name.
The Spanish flu was the first reported pandemic caused by the H1N1 influenza virus, with 2009 swine flu being the second. While most influenza outbreaks as a rule kill the very young and the very old, with a higher survival rate for those in between, the Spanish flu resulted in a higher than expected mortality rate for young adults. According to experts, this is mostly due to wartime malnourishment, overcrowded medical camps and hospitals, and poor hygiene, but not to the flu strain specifics.
Besides all those pandemics, humankind has passed through many other similar crises which could be also called pandemics, or be lowered to epidemics. Since the Middle Ages and until the 20th century, cholera outbreaks were reported on a regular basis, with the one starting in India in 1852 and passing through Russia and Europe to reach America by 1860 being the most deadly. And this one was important because that's when doctors found the cause of the disease, after which disinfecting and boiling drinking water became common throughout the world.
A very specific case was the pandemic that raged across the Americas in the centuries following its conquest by the Europeans. Experts call such a phenomenon “virgin soil epidemic” and define it as one in which “the populations at risk have had no previous contact with the diseases that strike them and are therefore immunologically almost defenceless”. In fact after 1492, Europeans brought to the Americas a wide range of diseases, including smallpox, diarrhoea, typhoid, etc., which were unknown to natives and made them die in scores. Numbers are unclear but according to some estimates by early 19th century up to one third of Native Americans had died due to imported diseases.
And finally come modern pandemics - SARS (2003), MERS (2012) and swine flu (2009). The first two were caused by a coronavirus similar to the one raging across the globe right now. However, both were less contagious and didn't turn into a global phenomenon, although the mortality rate was much higher. As for the swine flu, caused by the well-known H1N1 strain, it affected up to 20% of the then global population, or around one billion people, with fatalities of up to 18,000.
Humankind has passed through all these and many other smaller and bigger epidemics. It will overcome the Covid-19 challenge as well. Until the next outbreak. With the ongoing globalisation, transmitting diseases will become ever more easy, but also the information about them, and the possible cures. Since the dawn of human civilisation, man and disease go hand in hand, this will not change until the very end.