Epidemics

Introduction – Epidemics

The English Curate Thomas Malthus (a strong influence on Darwin) in his Essay on the principle of population (1798) theorized that human population would increase indefinitely unless reined in by birth control, famine, war, or disease. Somehow humanity has escaped the more unpleasant aspects of population control by using cheap energy, adopting new technologies, mass production (esp. food), and by the application of modern medicine.  However, existential risks pointed out by Malthus remain to haunt us.

An epidemic is the rapid spread of disease to a large number of people in a given population within a short period of time while a pandemic is an epidemic of an infectious disease that has spread across a large region, for instance multiple continents or worldwide, affecting a substantial number of individuals. Among the better-known diseases are Cholera, Dengue fever, Influenza, Typhus, Smallpox, Measles, Tuberculosis, Leprosy, Malaria, Yellow fever.Current pandemics are HIV/AIDS and COVID19.

Brief history of epidemics

Throughout the annals of human history, epidemics have plagued civilizations, leaving behind a trail of devastation and despair. The history of epidemics traces back to ancient times, where infectious diseases ravaged populations with little understanding of their causes or cures.

One of the earliest recorded epidemics dates back to the third century BCE, when the Athenian plague swept through the city-state during the Peloponnesian War. Historians believe that this epidemic, possibly a form of typhoid fever or Ebola, decimated a significant portion of the population, including the famed Athenian general, Pericles. The lack of medical knowledge and resources in ancient Greece only exacerbated the impact of the disease, leading to widespread fear and social upheaval.

Moving forward in time, the Black Death of the 14th century stands out as one of the most infamous pandemics in history. Believed to have been caused by the bacterium Yersinia pestis, this deadly disease claimed the lives of an estimated 75 to 200 million people across Europe, Asia, and Africa. The rapid spread of the plague was facilitated by fleas carried by rodents and exacerbated by unsanitary living conditions prevalent in medieval cities. The catastrophic death toll of the Black Death forever altered the course of European history, leading to socio-economic upheaval and the decline of feudalism.

The 19th and 20th centuries witnessed significant advancements in the understanding and control of epidemic diseases. The discovery of the germ theory of disease by Louis Pasteur and Robert Koch revolutionized medical science and paved the way for the development of vaccines and antibiotics. The emergence of modern public health practices, such as sanitation, vaccination, and quarantine, played a crucial role in preventing and controlling epidemics. The eradication of smallpox in 1980 stands as a testament to the effectiveness of global vaccination campaigns in combating infectious diseases.

In more recent times, the world has grappled with the emergence of novel infectious diseases such as HIV/AIDS, SARS, Ebola, and most notably, COVID-19. The rapid globalization and interconnectedness of the modern world have enabled these diseases to spread rapidly across borders, challenging public health systems and testing the resilience of societies worldwide.

In conclusion, the history of epidemics is a grim reminder of the fragility of human existence and the constant threat posed by infectious diseases. From ancient plagues to modern pandemics, the struggle against epidemic diseases has been a defining feature of human civilization. As we continue to confront new challenges in the realm of public health, the lessons of the past serve as a poignant reminder of the importance of vigilance, preparedness, and cooperation in the face of epidemic threats.(AI)

Spread by exploration & travel

Most virulent diseases are zoonoses (originating from animals, often domestic) and spreading rapidly in situations where there is close contact between humans travelling over potentially great distances e.g. bubonic plague along the Silk Road in ancient times, and international air travel today.

Wikipedia gives an account of encounters between European explorers and populations in the rest of the world who often introduced epidemics of extraordinary virulence. Disease killed part of the native population of the Canary Islands in the 16th century (Guanches). Half the native population of Hispaniola in 1518 was killed by smallpox. Smallpox also ravaged Mexico in the 1520s, killing 150,000 in Tenochtitlán alone, including the emperor, and in Peru in the 1530s, aiding the European conquerors.[80] Measles killed a further two million native Mexicans in the 17th century. In 1618–1619, smallpox wiped out 90% of the Massachusetts Bay Native Americans. During the 1770s, smallpox killed at least 30% of the Pacific Northwest Native Americans. Smallpox epidemics in 1780–1782 and 1837–1838 brought devastation and drastic depopulation among the Plains Indians. Some believe the death of up to 95% of the Native American population of the New World was caused by Europeans introducing Old World diseases such as smallpox, measles and influenza. Over the centuries, Europeans had developed high degrees of herd immunity to these diseases, while the indigenous peoples had no such immunity.

Smallpox, introduced by European settlers in 1789 to the Australian continent, devastated the Australian Aboriginal population, killing up to 50% of those infected with the disease during the first decades of colonisation. It also killed many New Zealand Māori. In 1848–49, as many as 40,000 out of 150,000 Hawaiians are estimated to have died of measles, whooping cough and influenza. Introduced diseases, notably smallpox, nearly wiped out the native population of Easter Island. Measles killed more than 40,000 Fijians, approximately one-third of the population, in 1875, and in the early 19th century devastated the Great Andamanese population. The Ainu population decreased drastically in the 19th century, due in large part to infectious diseases brought by Japanese settlers pouring into Hokkaido.

Researchers concluded that syphilis was carried from the New World to Europe after Columbus’s voyages. The findings suggested Europeans could have carried the nonvenereal tropical bacteria home, where the organisms may have mutated into a more deadly form in the different conditions of Europe.] The disease was more frequently fatal than it is today. Syphilis was a major killer in Europe during the Renaissance. Between 1602 and 1796, the Dutch East India Company sent almost a million Europeans to work in Asia. Ultimately, fewer than a third made their way back to Europe. The majority died of diseases. Disease killed more British soldiers in India and South Africa than war.
As early as 1803, the Spanish Crown organized a mission (the Balmis expedition) to transport the smallpox vaccine to the Spanish colonies, and establish mass vaccination programs there. By 1832, the federal government of the United States established a smallpox vaccination program for Native Americans. From the beginning of the 20th century onwards, the elimination or control of disease in tropical countries became a driving force for all colonial powers. The sleeping sickness epidemic in Africa was arrested due to mobile teams systematically screening millions of people at risk. In the 20th century, the world saw the biggest increase in its population in human history due to a drop in the mortality rate in many countries as a result of medical advances. The world population has grown from 1.6 billion in 1900 to an estimated 6.8 billion in 2011.

Timeline of major epidemics

BCE

430 to 426 BCE – Plague of Athens – during the Peloponnesian War typhoid fever killed a quarter of the Athenian troops and a quarter of the population

CE

161 – Han plague – there were outbreaks of plague in 151, 161, 171, 173, 179, 182, and 185 contributing to the collapse of Han Empire

165 – Antonine plague – Also known as the Plague of Galen, it was an ancient pandemic that broke out across the Roman Empire, through Asia, all Roman cities in Italy, and Greece. Eventually, it reached Spain, Egypt, and North Africa among other areas. At the height of the pandemic, it killed 2,000 people per day. Many believe that it was caused by smallpox and measles: it kills 5 million people in Roman Empire

541-549 – Justinian plague – the Plague of Justinian was a pandemic that afflicted the Byzantine (Eastern Roman) Empire and especially its capital, Constantinople, as well as the Sasanian Empire, and port cities around the entire Mediterranean Sea, as merchant ships harbored rats that carried fleas infected with plague

1331-1353 (often listed as 1345) – Black Death – Black Death, pandemic that ravaged Europe between 1347 and 1351, taking a proportionately greater toll of life than any other known epidemic or war up to that time. The Black Death is widely believed to have been the result of plague, caused by infection with the bacterium Yersinia pestis. Modern genetic analyses indicate that the strain of Y. pestis introduced during the Black Death is ancestral to all extant circulating Y. pestis strains known to cause disease in humans. Hence, the origin of modern plague epidemics lies in the medieval period. Other scientific evidence has indicated that the Black Death may have been viral in origin. It swept across Europe killing up to two-thirds of Europe’s population with 40 million victims worldwide (1345-1351)

1490 – Syphilis Epidemic – the earliest references to the disease are when it broke out among French troops besieging the city of Naples. Initially known as Morbus gallicus (the French Disease), it soon became epidemic throughout Europe. The disease left visible and disfiguring signs of infection, which led to social stigmatization. Most damaging in its late stages, it often produced severe disabilities and even death. Believed to be a new disease imported from the Americas

1492-1900 – American Small Pox – smallpox did not exist in the Americas, until it was brought from Europe where it was endemic (constantly present). Settlement of the east coast of North America in 1633 in Plymouth, Massachusetts was accompanied by devastating outbreaks of smallpox among Native American populations and later among the native-born colonists

1665 – Great Plague of London – an epidemic that ravaged London, England, from 1665 to 1666. City records indicate that some 68,596 people died during the epidemic, though the actual number of deaths is suspected to have exceeded 100,000 out of a total population estimated at 460,000. The outbreak was caused by Yersinia pestis, the bacterium associated with other plague outbreaks before and since the Great Plague of London. The Great Plague was not an isolated event—40,000 Londoners had died of the plague in 1625—but it was the last and worst of the epidemics. (bubonic plague)

1816-1826 – First cholera pandemic. Cholera had been around for a long time in India, but it took the development of trade routes and travelers to help spread it worldwide. The first pandemic starts in India, and spreads to the Middle East, Russia and China. Mortality must have been extremely high, but exact numbers are not available. The British Army recorded 100,000 deaths just amongst its troops. There have been 7 cholera pandemics since then, with the latest one starting in 1961, and continuing to the present.

1829-1851 – Second Cholera Pandemic – 100,000 killed

1832 – New York Cholera epidemic

1850 – Start of the third plague pandemic (last ‘great’ plague). Starts in China, spreads worldwide. Kills 12 million people 

1852-1860 – Third Cholera Pandemic. Starting in China, it spread into India, where 10 million people died

1817 – Indian Cholera – according to the World Health Organization cholera is an acute diarrheal infection caused by the ingestion of food or water contaminated with the bacterium Vibrio cholerae. Three years after it spread throughout India it reached different countries in Asia. In 1821 it was brought by British troops traveling from India even to countries outside Asia

1870-1874 – Small pox epidemic – before the world completely rid itself of this horrendous disease, it swept through continents killing three out of ten victims. Those who survived were left with deep scars which were even found in 3000-year-old mummies, showing that it ravaged ancient civilizations for thousands of years. But it was in 1870 during the Franco-Prussian war that smallpox spread throughout the world. From Europe, it reached Asia through America causing 500,000 deaths worldwide

1889 – Russian Flu (1889–1890) – Called the first-ever modern flu pandemic, the Russian flu which started in St. Petersburg, spread through Europe infecting even prominent world leaders. After a few months, it reached virtually every part of the planet. An estimated 1 million people died of the Russian flu

1899 – 1923 – Sixth Cholera Pandemic. 800,000 die

1916 – Polio Epidemic. 9000 cases in New York

1918 – 1920 Spanish Flu Pandemic – considered the deadliest in history, infecting 1/3 of the world’s population and killing 20 to 50 million people worldwide. It came in three waves. The first wave was almost like the common flu and hit in the spring of 1918. The second wave that appeared in the fall of the same year was deadlier. It killed people within hours or a few days after the onset of symptoms. The third wave that came the following year was just as deadly and added more to the death toll. Overall, it infected half a billion people around the world, including on remote Pacific islands and in the Arctic, killing 20 to 100 million. One-third of the world population was infected

1957-1958 – Asian Flu – The 1957 influenza pandemic (the “Asian flu”) was one of the famous influenza pandemics in history. The “Asian Flu” was a category 2 flu pandemic outbreak of avian influenza that originated in China in early 1956 lasting until 1958. It originated from mutation in wild ducks combining with a pre-existing human strain. A vaccine for H2N2 was introduced in 1957, and the pandemic slowed down. There was a second wave in 1958, and H2N2 went on to become part of the regular wave of seasonal flu. In 1968, the H2N2 Asian flu disappeared from the human population and is believed to have gone extinct in the wild. Vials of H2N2 influenza remain in laboratories across the world. The 1957 pandemic influenza H2N2 Hemagglutinin (HA) proteins and antibodies were the main research tools for this influenza pandemic2 million deaths

1968 – H3N2 Hong Kong Flu the 1968 flu pandemic was caused by the influenza virus. Although relatively not as deadly, the virus was highly contagious that it spread throughout Southeast Asia within two weeks after it first emerged in Hong Kong in July 1968. By December the virus has reached The United States, United Kingdom, and other countries in Europe. It killed an estimated one million people.

1970 – Indian Small Pox Epidemic – 100,000 cases, 20,000 deaths. India became free of smallpox in 1975

1981-> present – HIV/AIDS pandemic – The first case of acquired immunodeficiency syndrome (AIDS) was reported in 1981. Since then HIV (Human Immunodeficiency Virus) has spread globally infecting more than 65 million people according to the Centers for Disease Control and Prevention. There is still no known cure for this sexually transmitted disease but there are already treatments that keep the virus under control allowing people to live longer. 25 million deaths worldwide

2002-2004 – SARS epidemic – Severe Acute Respiratory Syndrome (SARS) was first reported in Guangdong, China in February 2003 although experts believe it started in China as early as November 2002. After a few months, it spread throughout countries in North America, South America, Europe, and Asia. It infected 8,098 people worldwide and killed 774 people. The disease caused high fever, body aches, and dry cough which then led to pneumonia in some cases. Starts in Asia, and spreads worldwide. 8,000 cases, 774 deaths

2008-2009 – Zimbabwe cholera outbreak , 4, 293 deaths

2009-2010 – Flu pandemic. 14, 286 deaths worldwide

2010-> present – Haiti cholera outbreak 4,750 + deaths

2019 – Coronavirus (CoViD19) – a SARS virus believed to have originated from a food market in Wuhan China in December 2019, the virus spread throughout Europe, the rest of Asia, North America and virtually every part of the world within months. By May 2022 around 6 million people had died