Pandemic vs Epidemic : What’s the difference? After COVID-19 caused a pandemic in 2020, this has been a popular topic on the minds of everyone. We cover a lot of ground here, dissecting the truth about pandemics and how they differ from an epidemic.
While a pandemic and epidemic are similar, the difference is about the scale of the outbreak. A pandemic affects more people over a larger area than an epidemic. With the Coronavirus making headlines around the world, a lot of people want to know the difference between a pandemic and an epidemic. This article is going to discuss the topic in detail.
Pandemic vs Epidemic
I’ll start off with the textbook definition of both pandemic and epidemic, so that the distinction between the two terms are clear. Though this is intended as a comprehensive article covering all matters concerning pandemic and epidemic. I’ll be looking into history, so that we can gain a better understanding of how a pandemic (or epidemic) starts. How they affect us as individuals and society at large. What are the global economic realities we have to face? How can we prevents an epidemic from becoming a pandemic?
While I will be referring to the popular topics relating to the Coronavirus (COVID-19), the fact is that this is not just about our current situation. You can read more about Coronavirus in a recently published article (URL link). This provides the full story on the COVID-19 situation, with all the advice you need.
What is an Epidemic?
The accurate definition of an epidemic is an outbreak of an infectious, potentially deadly, disease that spreads rapidly, affecting many people simultaneously. The term is derived from the Greek word epidemios. Demios, meaning people, with the additional suffix epi, indicating amongst the people. This can also be interpreted in a modern context as being within the country.
What is a Pandemic?
When an epidemic spreads over a wider geographical area, affecting more people, it becomes known as a pandemic. Originating from the Greek word Pandemos, meaning all of the people. A pandemic can be seen as a multi-national outbreak, affecting everyone.
So, when the Coronavirus began it was an epidemic, affecting a small city in China. As the disease spread, first across China, and then to other countries, it was reclassified as a pandemic.
While the definition of a pandemic vs epidemic may seem like an arbitrary, academic distinction, the impact has greater consequences. Through the course of the article, this should become clear.
History of Great Epidemics
Since the earliest civilizations, epidemics have affected cities around the world. The impact has varied, depending on geography, and the medical understanding of the time. By observing epidemics and pandemics of history, academics, medical professionals, and we as laymen, can gain a better understanding of the implications and effects.
Plague of Athens
The first recorded epidemic was the Plague of Athens (429 – 426 BC). During the time of the epidemic, approximately 25% of the Athenian population died (75,000 – 100,000 people).
It is uncertain what the diseases was. Throughout history, many have speculated on the identity of the virus or bacteria. It was originally suspected to be an early outbreak of bubonic plague. Though subsequent theories have disputed this. Other speculations include typhus; smallpox; measles and toxic shock syndrome. In 2005, a DNA sample, taken from dental pulp recovered from an ancient Greek burial pit, lead scientists to believe that the plague of Athens was most likely typhoid fever.
The cause of the epidemic is significant, as it culminates from a sequence of events. During the Peloponnesian war (431 – 404 BC), Pericles (general of Athens) ordered that all Athenians retreat to within the city walls. Subsequently, many inhabitants of the Attic countryside migrated to the city. As Athens was already a crowded city, the influx of people from the neighboring areas led to uncontrolled overcrowding. This, in turn, led to a shortage of supplies and unsanitary conditions.
According to the Greek historian Thucydides, the disease was brought from Ethiopia, travelling through Egypt and Libya. While the origins will always remain a mystery, the consequences were dire. With the overcrowding of the city and a lack of medical knowledge, the disease spread rapidly. Care givers and medical practitioners were affected in large numbers as people of that time had no idea how infectious diseases spread.
In a time of religious superstition, many Athenians believed that the gods had forsaken them. Without the moral guidance of religion, there was mass lawlessness. This was exasperated by desperation and fear. I will discuss these psychological implications in more detail later as, even in modern times, this is a danger with epidemics and pandemics.
Epidemics of the Ancient World
Historical accounts of epidemics up to the middle ages are vague, due mostly to a lack of medical understanding. Additionally, most of the accounts are European, with the exception of the Japanese smallpox epidemic from 735 – 737 BC.
Despite the lack of medical understanding, there are certain social and historical events that are well documented, giving us some insight on how the early epidemics came about and how they were spread. There are some interesting common facts that can be recognized from all of the early epidemics.
- Most epidemics in ancient times resulted from war activity. This would generally be soldiers returning from foreign countries with unknown infections from which the local population had little or no immunity.
- Another wartime cause for pandemics resulted from people being contained within walled cities (as with the plague of Athens). This would people seeking refuge in cities, or wartime sieges of cities. Overcrowding and primitive sanitation, lead to rapid spread of disease.
- Another, less common cause of early epidemics was through trade. Ships would return from foreign countries with rats and other vermin that carried disease.
- The spread of early epidemics were always complicated by religious superstition, leading to social disruption and unrest.
The Age of European Colonization
Mexican Smallpox Epidemic
The Mexican smallpox epidemic of 1520 was significant for several reasons. This was the first time Europeans were responsible for the spread of disease to the “new world”. This lead to a moral crisis in later years, which is still being addressed to this day. The spread of disease, as well as invasive species, resulted in new practices and international laws in later years.
What is most striking about the smallpox epidemic of 1520, and the Cocoliztli epidemics that followed (1545 – 1548 & 1576) was the devastating effect it had on the population of Mexico. It is estimated that up to 80% of the Mexican population died during the early years of the Spanish invasion.
During the smallpox epidemic of 1520, an estimated 5 – 8 million people died. The Cocoliztli outbreak of 1545 – 1548 killed an estimated 5 – 15 million people. A later Cocoliztli epidemic, in 1576, killed a further 2 – 2.25 million people.
The reason for the massive impact that these diseases had on the population was due to a lack of natural immunity amongst the local population. Smallpox and cocoliztli were new to the North American continent. While Europeans also died from these diseases, many survived as immunity had developed over thousands of years, resulting in fewer deaths.
History of Pandemics
The origins of pandemics seems to be quite clear. From the ancient world to the time of European global colonization, there appears to be one common cause for most early pandemics – colonization.
This is fairly obvious, as people conquering new territories encounter new, and foreign diseases. Similarly, the colonialists carry virus and bacteria for which the colonized people have no immunity.
Another cause for pandemics, throughout history, has been international trade. This is something I’ll discuss in greater detail when looking into the economic impact of pandemics.
From the 20th century onwards, pandemics have taken on new proportions with the advent of increased international travel. While pandemics have been numerous through the ages, there are several that are of greater significance. I’ll be discussing the pandemics that are most recognized for the impact that they have had on history.
Antonine Plague
While not of great historical significance, the Antonine plague (165 – 180) was the first pandemic in known history. For this reason, it has some historical importance. As with all of the early epidemics and pandemics, the actual disease is unknow. It is suspected to have been either smallpox or measles.
The cause, however, seems to be quite clear. The Antonine plague appears to have been brought to Rome by military troops returning from the near east (Asia Minor).
The disease spread, fairly rapidly, throughout the Roman empire. The people of Europe had not before encountered the disease and it was responsible for 5 – 10 million deaths. In some instances entire villages and towns were destroyed.
Black Death
Probably the most notorious of all historical pandemics, the black death of the middle ages brought about mass fear throughout Europe, the most crucial period being 1331 -1335. The pandemic spread through all of Europe, most of Asia and North Africa. Responsible for an estimated 75 – 200 million deaths, it is believed to have killed anything from 20 to 60% of the European population.
Also known as the bubonic plague, or the great plague, this was the second pandemic on the European continent, following the Antonine plague more than 1,000 years prior. The plague is identified medically as bacterium Yersinia pestis. The bacteria can be spread by exposure to meat or blood of an infected animal, usually through a break in the skin. It is also spread by the inhalation of droplets containing the bacteria (human to human transmission), resulting in lung infection. Flea bites and bites or scratches from cats is another common cause.
The outbreak of the pandemic is believed to have been caused by fleas, carried by rodents migrating from Asia. Climate change forced rodents to move westward in search of new habitats, as the grasslands of Asia were decimated by drought. However, there are more compelling arguments to suggest that the black death was a result of Mongolian imperial invasion. It is likely that both these scenarios played a role in the spread of black plague.
Historical evidence suggests that the original bubonic epidemic started in China (circa 1330). Mongolian traders, along the historic Silk Road, are believed to have spread the disease westward. Reports of the Mongolian army suffering from the disease are numerous. During the 1346 siege of Kaffa, Mongolian emperor, Jani Beg, is rumored to have catapulted infected corpses into the city. This is the first known use of biological warfare, albeit a primitive method by today’s standards.
Amongst all the speculation and theory, some facts are clear. The disease entered Europe through the Crimean, reaching Constantinople (capitol of the Eastern Roman Empire) in 1347. In one way or another, the disease was spread through Mongolian trade, warfare, pestilence migration, or a combination of these factors. From here, Italian merchant ships spread the disease.
The black death spread from Italy, into Spain and then France. Later moving into England and across Northern Europe. Superstition of the time resulted in a theory that the disease was spread by bad air. Although not medically substantiated at the time, this theory was effective, as coughing or sneezing spreads the disease. The practice of covering one’s nose and mouth, to prevent inhaling “bad air” can be compared the modern-day practice of wearing masks to prevent airborne infection.
While the period of the black death pandemic is historically noted as the middle ages, it was not entirely eliminated until the late 19th century. Periods of particularly cold weather would cause a decrease in rodent populations, thereby reducing the fleas that carried the disease. Similarly, heatwaves would cause a resurgence of localized bubonic epidemics.
The next notable outbreak of bubonic plague, after the black death, was the plague of London (1592 – 1593). This was a later outbreak of the black plague, during the reign of Queen Elizabeth I. Up to 20,000 people died from the plague during this period. There are several more incidents of the plague in England and other countries over the centuries. The great plague of London (1665 – 1666) killed an estimated100,000 people.
Russian Flu
The second most deadly flu pandemic of all time was the Flu pandemic of 1889 – 1890. This was also the first global pandemic, affecting countries on every country in the northern hemisphere.
Originally known as Asiatic Flu, or Russian Flu, the disease has now been identified as Influenza A virus subtype H3N8. The disease was estimated to have killed around 1 million people internationally.
The end of the 19th century was a time when global travel was becoming more common. The Russian Empire, where the pandemic began, had over 200,000 miles of railways connecting east with west. International travel had increased by way of the steam ship which made it possible for people to cross oceans faster and safer than before.
The pandemic started in St Pietersburg Russia, reaching a peak in this country in December 1889. It took four months to spread across Europe, Asia, and North America. In the United States, the pandemic reached a peak a month later, January 1890.
Spanish Flu
The Spanish flu pandemic of 1918 is the most infamous of them all. It was responsible for up to 100 million deaths. It is the most deadly pandemic the world has ever seen.
This was the first recorded outbreak of the H1N1 virus, which later reemerged in 2009, and became commonly known as Swine Flu. However, the second outbreak was not as deadly. Greater awareness of global pandemics, and better international control measures, meant that global pandemics subsequent to the Spanish flu, were not as devastating. Regardless, the 2009 H1N1 pandemic killed between 150,000 and 575,000 people.
The reason why the Spanish flu pandemic was particularly deadly was a combination of factors. The disease was first contracted by soldiers serving during World War I. This was how it spread as widely as it did.
It is believed that the virus originated in Kansas. Though, it was from a British military hospital in France, that the disease spread across Europe and then the rest of the world. With US soldiers being deployed all over the world, the spread was uncontrolled and rapid.
Due to wartime conditions, the pandemic was fueled by malnourishment and the often unsanitary conditions that soldiers found themselves in. The stress of war is also cited as a possible cause for the inordinately high death rate.
A more recent hypothesis, published in the journal Clinical Infectious Diseases (2009), suggests that Aspirin poisoning may have been responsible many deaths. Shortly after the surgeon general of the US Army suggested large doses of aspirin for Spanish flu patients (8 – 31 grams), the death rate spiked. It is unknown how many deaths could have been prevented by better medical knowledge, but ignorance of the disease certainly played a role.
This was the first pandemic to affect every continent. Again, the war would have been the major contributing factor for this. Troops were recruited from across the British empire and commonwealth to serve in the war effort. So unlike, the Russian flu pandemic, of two decades before, Spanish flu also affected the southern hemisphere. Recruits from Australia and South Africa took the virus home and it spread from there.
Following the Spanish flu pandemic of 1918, there have been several similar pandemics. The most severe flu pandemic to follow was the Asian flu pandemic of 1957 -1958 (H2N2), killing an estimated 2 million people.
Apart from HIV/AIDS, flu strains have been the only major pandemics in developed countries from the 20th century onwards. Though, there have been others that have had a minor impact, like Ebola (EVD). Africa, in particular, has suffered more epidemics and pandemics in recent history, this is mostly because of poverty and a lack of information amongst the general population.
The recent outbreak of COVID-19 may prove to be the exception. As of 18 March 2020, there have been 8,270 reported coronavirus deaths. While alarming, these deaths pale in comparison to the millions that have died from various flu pandemics over the last 100-years.
HIV/AIDS
Without a doubt, the most infamous and reported upon pandemic in human history has to be HIV/AIDS. This has a lot to do with the original perceptions around sexuality and morality. When the disease was first recognized in the western world (circa 1981), it was believed to only affect homosexuals. Soon thereafter, intravenous drug users were also identified as high risk categories.
Because of controversy and social bias, initial HIV/AIDS infections were often kept secret, leading to a rapid spread of the disease. I’m going to discuss this pandemic in detail because it is more complicated than any other and has had massive social implications.
Difference between HIV and AIDS?
The distinction between HIV and AIDS is significant as it plays a major role in the spread of the virus. This is due to the nature of the virus which mutates in various stages. This means that a person can be infected with the virus and not know it. Unlike other viruses, where acute symptoms are detected within days of infection, the HIV virus can go unnoticed indefinitely, with only minor flu-like symptoms, or none at all.
HIV
Human immunodeficiency virus (HIV) is a virus that attacks the cells in our body known as CD4 which are responsible for immunity. This affects our defense against infection. There is no natural defense against HIV. In many cases, the body is able to contain the virus, but it cannot be removed once a person is infected. It is, therefore, possible to live with the virus without any recognizable symptoms of the disease known as AIDS. Antiretrovirals drugs are used to control the virus. While this is not a cure for AIDS, it allows patients to lead a normal life once infected. HIV is transmitted between humans through certain bodily fluids:
- Blood
- Semen
- Vaginal fluid
- Anal fluid
- Breast Milk
AIDS
Acquired immune deficiency (AIDS) is a condition that results from stage 3 HIV. It is detected by measuring the CD4 count in the blood of a person infected with HIV. A healthy person has a CD4 count of 500 – 1,600 cells/mm³. When the CD4 count reaches 200 cells/mm³ or less, a patient is diagnosed as having AIDS. The disease is not directly related to death, but rather restricts our ability to fight off other infections. Both HIV and AIDS can lead to opportunistic infections as listed below.
- Certain cancers – cervical cancer; lung cancer; Kaposi’s sarcoma and lymphomas.
- Candidiasis which is an infection of the lungs or throat.
- Cytomegalovirus causing blindness and other complications.
- Pneumocystis pneumonia, a potentially fatal fungal pneumonia.
- Toxoplasmosis which is a parasitic brain infection.
- Tuberculosis (TB), a bacterial infection of the lungs.
History of HIV/AIDS
While HIV was only fully recognized in the west during the 1980s, it is believed to have originated in the Democratic Republic of Congo in 1920. The virus was transmitted from chimpanzees to humans around this time.
Before 1970 only a few cases were reported, and little was known about the virus. It was not identified until much later. The epidemic started in the mid-1970s. Though at this time, the cause and spread of the virus was a mystery and cases were rare. HIV became recognized as a pandemic by the late 1980s.
In 1981, 5 unusual cases of Pneumocystis carinii pneumonia (PCP) were diagnosed. This was notable as PCP is a rare disease and the patients were young, previously healthy men. Around the same time, in New York, 2 equally unusual cases of Kaposi’s Sarcoma were reported. These were also young, previously healthy men. The only common link between these 7 cases is that all the infected men were homosexual. In the same year, the first cases of PCP were detected amongst intravenous drug users. By the end of 1981, there were 270 cases of young gay men with severe immune deficiency.
In 1982, numerous gay men in California were infected, leading to the belief that this was a sexually transmitted syndrome, affecting gay men. It was then identified by the name gay-related immune deficiency (GRID).
After several cases of the syndrome were recognized in hemophiliacs, the CDC designated the term Acquired immune deficiency (AIDS) to the disease.
In 1983, the first cases were reported amongst heterosexual women and new-born babies. It was later suggested that the babies had contracted the disease during childbirth, transmitted from an infected mother.
The retrovirus HTLV-III was identified as the cause of AIDS in 1984 and was renamed HIV in 1986. In 1985, the FDA authorizes the first test for HIV antibodies in the blood. The first anti-retroviral drug (AZT) was approved by the FDA in March of 1987. By December 1987, the World Health Organization reported 47,022 confirmed cases of AIDS in the US, out of 71,751 worldwide. At this time, the US was the country most affected by the disease. An estimated 5 – 10 million people were believed to have been infected with HIV.
Through the 1990s, public awareness of HIV/AIDS increased. Through the use of anti-retrovirals, and public information campaigns, AIDS deaths in the USA and Europe weren’t increasing as rapidly, but the death rate remained high. However, the opposite was true in Africa and Asia. By the end of 1995, there were 4.7 million new cases of HIV reported internationally. Of these, 2.5 million were in South East Asia, and 1.9 million in Sub-Saharan Africa.
By 1999, Aids was declared the number one cause of death in Africa by the World Health Organization, and the fourth most deadly disease internationally.
In 2011, trials of a new antiretroviral (HPTN 052), showed a 96% reduction in the transmission of HIV between couples, where one of them was HIV positive.
By 2013, deaths related to AIDS had been reduced from the global record high in 2005 by 30%. Since then, HIV and AIDS has become less serious in developed countries. This is due to lower infection rates, through public awareness, and wide access to treatment. It remains a problem in Southern Africa.
The Social Implications of HIV/AIDS
During the peak of the HIV/AIDS pandemic, the disease sparked massive social debate. Because the disease was mostly transmitted sexually, with gay men being most affected, religious fanatics responded with moral outrage. It wasn’t uncommon for prominent religious figures, even politicians, to claim that the disease was an act of god, sent to cleanse the world of sin.
During the 1990s, HIV and AIDS became the topic numerous films. Probably the most famous of these was Philadelphia, staring Tom Hanks. Through films, and constant media debate, the disease took on another dimension. Almost as great as the pandemic itself, the issue of gay rights, and acceptance, became a focal issue.
The death of celebrities from AIDS, like Freddie Mercury, Liberace, Rock Hudson, and many others, also brought attention to the disease and its impact on society. This is one of the poignant aspects to the pandemic. While the deadly impact of AIDS cannot be overlooked, it also raised many questions within society regarding morality and social tolerance.
Pandemics in Modern Times
Coronavirus has caused people of today to look at the effects, spread, and control of pandemics in a serious light. People are questioning why we still have epidemics and pandemics in an age of advanced medical science. Ironically, from the 20th century to date, epidemics have grown in number and severity.
Global Pandemic Increase
Since the Russian Flu Pandemic (1889 – 1890) to the present day, there have been more pandemics than any other period in history. Furthermore, the infection and death rate has been significantly higher than historical outbreaks. Reasons cited for the increased impact of pandemics are as follows:
- Increased global travel and integration
- Urbanization
- Greater exploitation of the natural environment.
Of the reasons mentioned above, I feel that international travel and urbanization are the greatest contributors. To provide some context, I’ll provide a comparison between ancient Rome and the largest city (by population) in the modern world, Hong Kong.
At the peak of the Roman Empire, the city of Rome had an estimated population of 1 Million. The city of Tokyo has 38 million inhabitants. An even more interesting comparison, is that the entire population of the Roman empire during the time of the Antonine pandemic (circa 165) was approximately 60-70 million people. This means that Tokyo, one of many large modern cities, has a greater population than the entire known world, during the time of the Antonine plague. This is of particular significance when we compare numbers. The maximum estimated death rate for the 1918 Flu Pandemic (approximately 100 million) is more than the entire Roman empire around 165 CE.
If we account for the frequency and volume of international travel, the picture broadens. In 2018, the busiest airport in the world was Hartsfield-Jackson International Airport (Atlanta), with over 107 million total annual passengers. It is logical that large, densely populated cities, combined with an immense volume of international travel will lead a greater likelihood for the spread of infectious disease.
International Measures to Combat Pandemics
Following numerous outbreaks of H1N1 and H2N2 viruses between 2002 and 2009, the World Health Organization has implemented several measure to combat the international spread of infectious disease.
The Revised International Health Regulations during Influenza A (H1N1) Epidemic, 2009 stipulates more stringent control measures, in accordance with an earlier 2005 regulation.
In essence, the regulations require greater vigilance amongst member states to declare outbreaks of infectious disease and inform the world Health Organization of any spread, or potential spread of these diseases.
I’m mentioning this, as it is of importance when discussing the social impact of pandemics and how these contribute to the spread of disease.
Socioeconomic Impact of Pandemics
When analyzing the effects of a pandemic form a social perspective, we cannot sperate human psychology from global economics. The two are fundamentally connected. Economic factors affect general human behavior and, conversely, our behavior affects the economy.
I believe there three basic human conditions that prevail during a time of crisis. This applies, not only to pandemics, but a general reaction to any form disaster that we cannot control. I’ve identified these reactions as denial, panic, and action.
Denial
As individuals, and as a society, we have a tendency to turn a blind eye to a situation that seems unbearable. In some instances this can be a coping mechanism, or it can be deliberate. I feel the latter is of great importance when dealing with pandemics.
When a potential epidemic is identified, doctors and nurses at local hospitals are the first to react. In their professional capacity, medical practitioners are bound to call for emergency measures. However, local authorities are often hesitant to draw attention to the situation. News of an epidemic easily leads to panic, with resultant social and economic turmoil.
The unfortunate consequence of public denial is that early containment, crucial to preventing a pandemic, is not implemented. This is the reason for international regulations requiring countries to declare any outbreak of infectious disease.
Panic
As we’ve seen in recent times, panic is an inevitable consequence following the announcement of a deadly pandemic. This has major economic and social implications. People immediately want to avoid public contact for fear of contracting the disease. This results in a disruption of social services and a decline in business activity, as people stop going to work. Businesses suffer as a result. Education is also disrupted, as many schools close.
Markets don’t like chaos, least of all, global panic. An inevitable reaction to a pandemic is uncertainty in stock markets. The recent coronavirus pandemic has caused erratic market reactions, with panic buying and selling causing unpredictability. Economists are referring to this as a seesaw effect. Economists are unable to predict trends in the market. This affects financial planning and general investment practices by banks, insurance companies, and governments.
The social impact of panic is the disruption of normal human interaction. People are reluctant to socialize, even to the extent of avoiding family contact. Conditions like depression and anxiety become more prevalent and stress can lead to abnormal social behavior.
In countries where the political situation is already unstable, the added anxiety of a pandemic can lead to mass protest, even public violence. If the general population is distrustful of the government, political tension is amplified.
Action
A public threat has the effect of heightening people’s awareness. This will lead to extraordinary achievements in some individuals. Doctors, nurses, and scientists are obvious candidates. Hospital staff are on alert during these times and their workload is increases. Within 2 days of the COVID-19 genetic sequence being identified, a prototype vaccine sequencing (mRNA-1273) was finalized.
Ordinary citizens all take action in various ways. From the simple action of washing our hands more regularly to social awareness, like volunteering to care for the elderly, everyone in society adapts to the needs of time.
Public institutions, like the World Health Organization and Center for Disease Control, become more vigilant in monitoring the disease and increasing awareness.
Resources:
- ‘Pandemic’ vs ‘Epidemic’ : How they overlap and where they differ
- Plague of Athens: Another Medical Mystery Solved at University of Maryland
- History of smallpox in Mexico
- Plague in the Ancient World: : A Study from Thucydides to Justinian
- What was the Black Death?
- The Influenza Pandemic of 1918
- Salicylates and Pandemic Influenza Mortality, 1918–1919 — Pharmacology, Pathology, and Historic Evidence
- HIV VS AIDS : What’s the difference?
- What are HIV and AIDS?
- Pandemics: Risks, Impacts, and Mitigation
- Global Trends in Emerging Infectious Diseases
