Top 10 Deadliest Diseases in Human History

The Top 10 Deadliest Diseases in Human History

Throughout the ages, humanity has faced numerous deadly diseases that have left a significant impact on our lives and the development of healthcare. While we have come a long way in combating these menacing foes, it is crucial to remember and learn from the past. In this article, we will explore the top 10 deadliest diseases that have shaped human history, delving into their origins, symptoms, and the strides made in battling them.

1. Bubonic Plague: The Scourge That Shook the World

The bubonic plague, also known as the Black Death or the Pestilence, is a fatal infectious disease caused by the Yersinia pestis bacteria. This ancient malady first made its appearance during the Plague of Justinian in 541-549 AD and has caused immense devastation throughout history.

Cradit: Wikimedia commons 

The Y. pestis bacteria spreads through fleas or small mammals, such as rodents, and is transmitted to humans via bites or scratches. While the plague can be found globally, the discovery of the bacteria in 1894 led to the development of antibiotics and other treatments, making it curable in most cases today.

Historical plague pandemics include:

First Plague Pandemic

: Spanning from the Plague of Justinian to the 8th century, this pandemic affected Asia, Africa, and Europe, claiming 15-100 million lives.

Second Plague Pandemic

: Beginning with the Black Death in 1346-1353, this pandemic lasted until the 1700s in Europe and Northern Africa, causing 75-200 million deaths.

Third Plague Pandemic

: Occurring from 1855 to 1912, this pandemic spread globally, with most outbreaks in China and India, resulting in 12-15 million deaths.

2. Influenza: The Ever-Changing Enemy

Influenza, commonly known as the flu, is a highly contagious respiratory illness caused by various types of influenza viruses. The earliest documented cases date back to 1510, but there is evidence suggesting its existence since 6,000 BC.

Flu pandemics usually occur when a new virus strain is transmitted to humans from another animal species, such as pigs, chickens, or ducks. Symptoms can range from mild to severe, including fever, runny nose, sore throat, muscle pain, headache, coughing, and fatigue.

Some of the deadliest influenza pandemics in history are:

1918-1920 "Spanish flu"

: Affecting the whole world, this H1N1 pandemic led to 17-100 million deaths.

1957-1958 "Asian flu"

: A worldwide H2N2 pandemic, resulting in 1-4 million fatalities.

1968 Hong Kong flu

: A global H3N2 pandemic that claimed 1-4 million lives.

2009 Swine flu pandemic

: A global H1N1/09 pandemic, causing 151,700 - 575,400 deaths.

3. The Watery Terror: Cholera

Cholera is a severe infection of the small intestine caused by the bacterium Vibrio cholerae. It is characterized by vomiting, muscle cramps, and watery diarrhea, which can lead to dehydration and, in extreme cases, death. Originating in the Indian subcontinent, cholera has sparked seven major pandemics since 1817.

The disease spreads through contaminated water containing human waste and the bacteria. Sadly, cholera still claims 50,000 to 120,000 lives annually. The 1854 cholera outbreak in London led Dr. John Snow to emphasize the importance of clean water in public health and the study of epidemiology.

Noteworthy cholera outbreaks include:

1817-1824 First cholera pandemic

: Affecting Asia and Europe, causing over 100,000 deaths.

1826-1837 Second cholera pandemic

: Spread across Asia, Europe, and North America, resulting in over 100,000 fatalities.

1846-1860 Third cholera pandemic

: A worldwide pandemic that claimed over 1 million lives.

1961-1975 Seventh cholera pandemic

: A global pandemic with an unknown death toll.

4. Smallpox: The Eradicated Nightmare

Smallpox, caused by the Variola virus, was once a highly contagious and deadly disease that left millions dead. Symptoms included fever, vomiting, skin rashes, and blisters. The first widespread outbreaks occurred in 18th-century Europe, but the origins of the disease remain unclear.

Through the development of a smallpox vaccine by Edward Jenner in 1798, the disease has been entirely eradicated. The vaccine, along with strict public health measures, played a crucial role in combating the disease, which killed approximately 500 million people in the 20th century alone.

Significant smallpox pandemics include:

735-737 Japanese smallpox epidemic

: Resulting in 2 million deaths, affecting one-third of the Japanese population.

1520 Mexico smallpox epidemic

: Causing 5-8 million fatalities, wiping out 40% of the population.

1707-1709 Iceland smallpox epidemic

: Leading to over 18,000 deaths, accounting for 36% of the population.

1775-1782 North American smallpox epidemic

: Affecting the continent, with over 11,000 deaths and impacting 30% of the population.

5. Typhus: The Lethal Trio

Typhus fever is a group of infectious diseases, including epidemic typhus, scrub typhus, and murine typhus, caused by bacteria transmitted by lice, fleas, and mites. Symptoms include fever, headache, and rash.

The first described cases of typhus date back to 1489 AD, and numerous outbreaks have occurred since then, typically in areas with poor sanitation and overcrowding. Today, typhus is rare and treatable with antibiotics like doxycycline.

Some of the deadliest typhus outbreaks include:

1489 Spain typhus epidemic

: Resulting in 17,000 deaths.

1812 Russia Typhus epidemic

: Causing 300,000 fatalities.

1817-1819 Ireland typhus epidemic

: Leading to 65,000 deaths.

1918-1922 Russia typhus epidemic

: Claiming 2-3 million lives.

6. HIV/AIDS: From Epidemic to Manageable Condition

First identified in 1981, HIV is the virus that causes AIDS (acquired immunodeficiency syndrome). The virus, which likely originated from African chimpanzees, was transmitted to humans in the early 20th century. HIV/AIDS was first detected in the Democratic Republic of the Congo in 1976, and for decades, there was no cure.

However, breakthrough treatments have transformed HIV into a more manageable chronic health condition. Annual deaths from HIV/AIDS have dropped from 2.2 million to 1.6 million globally, and as of early 2020, two people have been cured of HIV.

1981-present HIV/AIDS pandemic

: Affecting the entire world, with over 35 million deaths as of 2020.

7. Dengue Fever: The Mosquito Menace

Dengue fever is a tropical disease caused by the dengue virus and transmitted by mosquitoes, primarily the Aedes aegypti species. Symptoms include high fever, headache, vomiting, muscle and joint pains, and a skin rash. In severe cases, it can progress to dengue hemorrhagic fever, resulting in bleeding and death.

Dengue fever has been reported since the 5th century AD, but the earliest documented epidemic occurred in 1779, affecting Southeast Asia, Africa, and North America. Today, there is a vaccine for dengue, and antiviral drugs are being developed to treat the disease.

Notable dengue fever outbreaks include:

1778 Spain dengue fever outbreak

: With an unknown number of deaths.

2004-06 dengue outbreak in Singapore, India, Indonesia, Pakistan, and the Philippines

: Affecting around 20,000 people and causing around 1,800 deaths.

2010 dengue fever epidemic

: A global outbreak with 1,785,059 confirmed cases and 2,398 deaths.

8. Malaria: The Persistent Parasite

Malaria is a mosquito-borne infectious disease caused by the Malaria parasite, transmitted by the Anopheles mosquito. Symptoms include fever, fatigue, vomiting, and headaches. In severe cases, it can also result in yellow skin, seizures, coma, or death.

Today, there are several medications to prevent malaria and antimalarial medications to treat it. In 2020, a vaccine was developed, reducing the risk of malaria by approximately 40%.

Some of the worst malaria outbreaks include:

1600-1650 South America malaria epidemic

: With an unknown number of deaths.

1829-1833 Pacific Northwest malaria epidemic

: Resulting in 150,000 fatalities.

1906 malaria outbreak in Ceylon (now Sri Lanka)

: Leading to 80,000 deaths.

9. Coronavirus: The Ongoing Battle

COVID-19 is caused by the SARS-CoV-2 coronavirus and was first reported in Wuhan, China, in December 2019. The virus is primarily transmitted through droplets generated when an infected person coughs, sneezes, or exhales and causes symptoms ranging from mild to severe.

While there is no specific treatment for COVID-19, numerous management strategies are available, including oxygen support, antivirals, and vaccines.

2019-present COVID-19 pandemic

: Affecting the entire world, with over 167 million confirmed cases and 3 million deaths as of May 2021.

10. Yellow Fever: The Forgotten Foe

Yellow fever is a viral disease transmitted by mosquitoes, primarily the Aedes aegypti species. It causes symptoms such as fever, chills, loss of appetite, nausea, muscle pain, and jaundice. Severe cases can result in liver and kidney dysfunction, bleeding, and death.

Major yellow fever outbreaks include:

1793 Philadelphia yellow fever epidemic

: Causing over 5,000 deaths.

1819-1820 Savannah yellow fever epidemic

: Resulting in over 700 fatalities.

1905 New Orleans yellow fever epidemic

: Leading to over 400 deaths.

The development of a yellow fever vaccine in the 1930s has significantly reduced the risk of the disease, but sporadic outbreaks still occur in Africa and South America.