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4 Diseases That Impacted & Altered Human Existence

Humans may sit at the top of the food chain, but that doesn’t protect them from the specter of disease, which has disrupted the globe many times over.


Throughout history, humans have faced numerous challenges and obstacles that have shaped our existence. From developing advanced technology to producing food for millions, we have made remarkable progress in many areas. However, one aspect where we have often found ourselves powerless is in the face of deadly diseases. These epidemics have not only changed the population but also altered how those who survive live their lives. In this article, we will explore four diseases that have had a significant impact on human existence.

1. Bubonic Plague

The Bubonic Plague, also known as the Black Death, is a bacterial disease caused by Yersinia pestis. It is primarily transmitted by fleas carried by rats, but it can also spread through other modes such as direct contact with infected animals or humans. This disease has been recognized throughout history and has swept through different parts of the world multiple times.

History of the Bubonic Plague

The first recorded outbreak of the Bubonic Plague was in the 6th century during the Justinian Plague. It started in the Mediterranean region and lasted for approximately 200 years, claiming an estimated 25 million lives. The second major outbreak occurred in the 14th century, known as the Black Death, which killed around 50 million people in Europe alone. The last major outbreak was in the late 19th and early 20th centuries, affecting countries such as China, India, and the United States.

Impact on Human Existence

The Bubonic Plague has had a significant impact on human existence, both in terms of population and society. The massive death tolls from these outbreaks have led to a decline in population, causing economic and social disruptions. The fear of contracting the disease also led to widespread panic and discrimination against certain groups, such as Jews and foreigners.

Moreover, the Bubonic Plague has also influenced medical practices and advancements. The study of this disease has led to a better understanding of bacteria and how they spread, leading to the development of antibiotics and other treatments. It has also highlighted the importance of sanitation and hygiene in preventing the spread of diseases.

Current Status

While the Bubonic Plague still exists today, it is relatively uncommon in most parts of the world. According to the World Health Organization (WHO), there were 3,248 reported cases and 584 deaths worldwide in 2019. Most of these cases occurred in Africa, particularly in Madagascar. However, with proper treatment and prevention measures, the mortality rate for this disease is now very low.

YearReported CasesDeaths

2. Smallpox

Smallpox is a viral disease caused by the variola virus. It is highly contagious and can be transmitted through direct contact with an infected person or contaminated objects. This disease has been around for thousands of years and has had a significant impact on human existence.

History of Smallpox

The earliest evidence of smallpox dates back to ancient Egypt, where mummies have been found with pockmarked skin. It is believed that the disease was introduced to Europe during the Crusades and later spread to the Americas through European colonization. In the 18th century, smallpox was responsible for killing an estimated 400,000 people per year in Europe alone.

Impact on Human Existence

Smallpox has had a devastating impact on human existence, causing millions of deaths throughout history. It is estimated that between 300-500 million people died from smallpox in the 20th century alone. The disease also had a significant impact on indigenous populations, as they had no immunity to the virus brought by European colonizers.

In addition to the high mortality rate, smallpox also left many survivors with permanent scarring and disabilities. This not only affected their physical well-being but also their social and economic status. The fear of contracting smallpox also led to widespread discrimination against those who had survived the disease.

Eradication Efforts

In 1967, the WHO launched a global campaign to eradicate smallpox through mass vaccination programs. This effort was successful, and in 1980, smallpox became the first and only human disease to be eradicated globally. This achievement is considered one of the greatest public health accomplishments in history.

3. Spanish Flu

The Spanish Flu, also known as the 1918 Influenza Pandemic, was a deadly outbreak of the H1N1 influenza virus. It is estimated that this pandemic infected around 500 million people worldwide and caused an estimated 50 million deaths. This disease had a significant impact on human existence, particularly during the final years of World War I.

History of the Spanish Flu

The Spanish Flu got its name from Spain, where it was first reported in May 1918. However, it is believed that the virus originated in the United States. Due to wartime censorship, news of the flu was not widely reported until it reached Spain, which was a neutral country during World War I. The virus spread rapidly throughout Europe and eventually reached other parts of the world.

Impact on Human Existence

The Spanish Flu had a devastating impact on human existence, causing more deaths than the war itself. The high mortality rate, combined with the already weakened state of the population due to the war, led to severe social and economic disruptions. The pandemic also had a significant impact on healthcare systems, which were already overwhelmed by the war.

Moreover, the Spanish Flu also had long-term effects on society. It is believed that the virus caused an increase in mental health issues and had a lasting impact on the economy. The fear of another pandemic also led to changes in public health policies and practices.

Lessons Learned

The Spanish Flu highlighted the importance of preparedness and early detection in preventing the spread of diseases. It also emphasized the need for international cooperation in dealing with global health crises. The lessons learned from this pandemic have helped shape current pandemic response strategies and policies.

4. COVID-19

The ongoing COVID-19 pandemic has brought the world to a standstill, affecting millions of lives and causing widespread disruptions. This disease, caused by the SARS-CoV-2 virus, was first reported in Wuhan, China, in December 2019. Since then, it has spread to almost every country in the world, causing over 4 million deaths as of August 2021.

History of COVID-19

The exact origin of COVID-19 is still under investigation, but it is believed that the virus originated in bats and was transmitted to humans through an intermediate host. The rapid spread of the virus was aided by international travel and the highly contagious nature of the virus. The WHO declared COVID-19 a pandemic on March 11, 2020.

Impact on Human Existence

COVID-19 has had a profound impact on human existence, affecting all aspects of life. The high mortality rate, combined with the rapid spread of the virus, has put immense pressure on healthcare systems worldwide. The pandemic has also caused severe economic disruptions, leading to job losses and financial instability for many individuals and businesses.

Moreover, the pandemic has also highlighted existing social and economic inequalities, with marginalized communities being disproportionately affected. The lockdowns and restrictions imposed to control the spread of the virus have also had a significant impact on mental health, with an increase in cases of anxiety and depression reported.

Lessons Learned

The COVID-19 pandemic has highlighted the need for better preparedness and response strategies for future pandemics. It has also emphasized the importance of investing in public health systems and addressing social and economic inequalities. The development of vaccines in record time has also shown the potential of science and technology in fighting against diseases.


Throughout history, humans have faced numerous challenges, including deadly diseases that have had a significant impact on our existence. From the Bubonic Plague to COVID-19, these epidemics have caused widespread devastation and changed the course of human history. However, they have also taught us valuable lessons and led to advancements in medicine and public health practices. As we continue to face new challenges, it is essential to learn from the past and work towards a healthier and more resilient future.

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Nikos Georgiou
Hailing from Athens, Greece, Nikos Georgiou brings a distinct Mediterranean perspective to his exploration of Greco-Roman history. A graduate of the University of Athens, his work incorporates a deep understanding of the region's cultural legacy and the enduring influence of classical antiquity.

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