The plague that killed millions

Historians of medicine have long engaged with pandemics, examining how they both hinge upon and redefine connections between people and societies in ways that other global phenomena may interact. The millions killed so far by this pandemic makes us wonder if history is repeating itself and the curse of coronavirus is nothing but a deja vu of past tragedies.

Many ask what is the link between COVID-19 and the plague (under different names) and the misery inflicted over the centuries.  To start with let us define COVID-19.  It belongs to a family of viruses that have often infected mammals, especially bats, and is known to cause a mild respiratory illness such as the common cold in humans.

This particular strain however, can and did prove lethal.  It seems to have originated in Wuhan, China, possibly from a live animal market and shares many convincing genomic features with bat coronaviruses, as this animal host is known for fairly virulent, highly mutating viruses.  Perhaps, this should be a reminder for us to check the incidence of previous pandemics which devastated the world population, at a time when unfortunately, there was no vaccine available.

A glamorous historical reminder was the incidence of the so-called Justinian plague (Yersinia pestis) which struck in the 6th Century CE and killed as many as 50 million people, perhaps half the global population at the time. It’s usually spread by fleas.  These bugs pick up the germs when they bite infected animals like rats and mice.  The so-called first major pandemic, began at the time of the Byzantine emperor Justinian - circa 541 to 544 CE. Studies have shown that upon DNA analysis of bones found in graves, the type of plague that struck the Byzantine Empire during the reign of Justinian was bubonic, although it was very probable that there existed another two types of plague - ie pneumonic and septicemic.  All victims had succumbed to “swellings”.

Reading the text of historian, Procopius, living in the 6th century CE, he described victims suffering from delusions, nightmares, fevers and swellings in the groin, armpits, and behind their ears.  Many victims suffered for days before dying, while others died almost immediately after the onset of symptoms.

Another more recent variant of the bubonic plague did devastate the world during the 14th century CE - (better known as the Black Death). This monster killed upwards of 200 million people or nearly half the entire global population.  Victims first suffered pain, fever and boils, then swollen lymph nodes and blotches on the skin.  After that they vomited blood and died within three days.  Survivors also called it the Great Pestilence. Victorian scientists dubbed it the Black Death.

Again, it is transmitted by fleas that live on rodents and has symptoms, which usually appear within one to seven days after infection.  These include painful, swollen lymph nodes, in the groin, armpit or neck areas as well as fever, chills and coughing.  Originally, it reached the Crimea in 1346 and most likely spread via fleas on black rats that travelled on merchant ships.  It soon spread through the Mediterranean and Europe.

Next on the catwalk of plagues enter “influenza”.  This reminds us of the familiar tell-tale signs of sneezing, coughing, aching, and overall physical weakness.  However, this reached its apex in 1918, when a particularly virulent form of influenza appeared, called the Spanish Flu - causing more deaths (over 50 million) than had resulted from casualties during the First World War - the latter lasted four years.

One may ask - what are the symptoms of Spanish Flu?  Victims suffer massive pneumonia and fatal pulmonary complications: they literally drowned in their own body fluids. For the medically minded, one can explain how victims had their lungs filled with fluid and their skin became markedly discoloured from the lack of oxygen. Mysteriously, it killed more young than old.  The death rate was greatest among ages 15 to 40.  This Flu pandemic of 1918–1919, caused approx. 50 million deaths worldwide.

Today, there are still doubts about its origins due to its unusual features, and the basis of its pathogenicity remain unanswered.  The public health implications of this pandemic are no mystery as the 1918 flu virus infected one in every three people on the planet.

Another major death reaper is HIV.  This is a pandemic that is still with us and lacks a vaccine, it killed an estimated 32 million people and infected another 75 million.  Moving on in the history of viruses that killed mercilessly is the Ebola virus disease (EVD).  This is a fever, which is severe, causing fatal illness affecting humans and other primates.

As can be expected, Ebola is transmitted to people from wild animals (such as fruit bats, porcupines and non-human primates) and then spreads in the human population through direct contact with the blood, secretions, organs or other bodily fluids of infected people, and with surfaces and materials contaminated with these fluids. Ebola has a high mortality rate of around 50% and its first outbreaks occurred in remote villages in Central Africa, near tropical rainforests.

A more recent killer is AIDS - first identified in 1981.  It destroys a person’s immune system, resulting in eventual death by diseases that the body would usually fight off. Those infected by the HIV virus encounter fever, headache, and enlarged lymph nodes upon infection.

When symptoms subside, carriers become highly infectious through blood and genital fluid.  In conclusion, this brief history of plagues and other viruses that regularly attack mankind seem to be part of our ancestral yoke.  As the world population continues to expand, this means more human beings get infected and in turn infect others, especially in densely populated cities.

We also have more livestock now and viruses can surreptitiously leap from animals to us.  It is no surprise, that Covid-19, saw its baptism in a crowded city in Wuhan, China before spreading to the rest of the world in a matter of months. But our scientists’ response to it has been swift and in less than a year there are about ten vaccines which can effectively cure the patient and create a “herd immunisation” shield if and when at least 70% of citizens receive the jab.

Scientists around the world are using cutting-edge tools to rapidly sequence the genome of the coronavirus, share along information about its virulence, and collaborate actively in testing new vaccines.  All this in record time than it could have been possible as medical science in the past had no clue how to fight the virus.