Epidemics have occurred throughout the different eras of civilization as the tightly packed nature of ancient cities combined with the often lacking hygienic practices provided an ideal environment for the propagation of viruses. An epidemic is a disease that has spread over a wide area and has infected multiple individuals in the same time period. An epidemic can escalate to a pandemic if it spreads even further and affects a large geographical area. Pandemics throughout history are an important marker to look back on not only because of the many lives they affected and took, but because they often were a precursor to social and economic shifts within societies and the world.
Most modern diseases are zoonotic diseases, infectious diseases caused by bacteria, parasites, or viruses which can travel from non-human animals to humans. Zoonotic diseases can be transmitted by air or through the saliva. It can also be transmitted through a vector, a “living organism that can transmit infectious pathogens between humans, or from animals to humans,” as is rumoured to be in the case of the current pandemic COVID-19.
One of the deadliest pandemics in human history was the bubonic plague which is also known as the black plague or the Justinian plague. There were three separate bubonic plague pandemics with the first occurring in the city of Constantinople, the capital of the Byzantine Empire, in 542 AD. Thought to be a punishment from God, the blame was attributed to people who were thought to be practicing immoral ways and behaviour. Byzantine historian Procopius blamed Emperor Justinian, declaring the emperor to be “either a devil, or [someone who] invoke[ed] God’s punishment for his evil ways.” With an estimated 25-50 million people killed over two centuries, an estimated quarter of the world’s population was wiped out due to the first wave of the bubonic plague.
Eight hundred years later during the Late Middle ages, a second wave of the black plague hit. This occurrence was the deadliest outbreak at the time and it continues to be the deadliest outbreak in human history, having killed an estimated 75 to 200 million people which was, at the time, between 30 to 60 percent of Europe’s population. Transmitted by fleas that were on sailing vessels arriving from trading ports in Asia, the plague quickly spread when the sailors arrived in Europe. The impact was so massive, it forever changed the course of human history since wages increased due to a rising demand of labour. A middle class was soon born and technological advancements followed to replace the lack of workers.
Smallpox was also one of the deadliest diseases, and it was second only to the black plague. Killing an estimated 56 million people, it wiped out approximately 90 percent of the Native American population when European colonizers arrived in America. Caused by the virus variants Variola major and Variola minor, the disease caused fevers, headaches, and most notably, bumps filled with thick fluid that covered the face and limbs. Smallpox had a 30 percent death rate, affecting mostly children and leaving the victim with permanent scars and occasionally blindness if they recovered. In 1796, English physician Edward Jenner discovered the vaccination for smallpox and the World Health Organization began a global vaccination program against smallpox. The disease was declared eradiated by 1980, and smallpox is, to this day, the only disease which affects humans to have been eradicated globally.
The Spanish flu (influenza), despite being named such, is not believed to be an outbreak that originated in Spain. Rather, the Spanish press, being one of the freest at that time, were the first to report of the occurrence of the disease. The H1N1 influenza virus caused the human influenza, and nearly 100 years later, caused a second pandemic termed ‘the swine flu.’ Though the origin of the virus is yet to be confirmed, it spread through Western Europe, and by July of 1918, five months after it was reported to have originated, it had spread to Poland. By the spring of 1919, the pandemic had run its course and killed an estimated 40 to 50 million people – half of them between the ages of 20 and 40.
Despite the undeniable impact of the Spanish flu, it has relatively little significance in public discussion and awareness. The rapid course of the disease may have contributed to this occurrence, as the disease died out over a year after its outbreak. Another theory revolves around the disease occurring at the same time as World War I and the demographic that the disease affected. Because many young men were already dying due to the war, the impact of the disease was not portrayed as strongly as many newspapers opted to focus on the war rather than the simultaneously occurring pandemic. Yet another theory attributes the under-reporting of the Spanish flu to the apolitical nature of the disease. Compared to a pandemic such as AIDS, the Spanish flu was not controversial and neither did it bring to attention several societal issues.
The novel coronavirus, as of March 21, 2020 has caused the death of 13,000 people. Having emerged in Wuhan, China in December, 2019, it is thought to be closely related to the SARS coronavirus and causes an illness known as COVID-19. By early 2020, the virus had reached North America and Europe and was soon recognized by the World Health Organization to be a pandemic. The impacts of this disease are yet to be known. To stay updated or to find out more information, please visit the Canadian government website and/or the World Health Organization.