21 of the deadliest epidemics and pandemics in history

Epidemics and pandemics

Some of the most severe epidemics and pandemics in history have condemned entire civilizations, causing millions of deaths. While these disease outbreaks still threaten humanity, thanks to advances in epidemiology, the consequences are no longer as devastating as in the past. Here are 21 of the worst epidemics and pandemics in history:

1. Antonine Plague: 165-180 AD

 When soldiers returned to the Roman Empire from war, they brought back more than just the spoils of victory. The Antonine Plague, which may have been smallpox, devastated the army and is believed to have killed over 5 million people in the Roman Empire. Many historians believe the epidemic first emerged in the Roman Empire, facilitated by soldiers returning home from a war against Parthia. The epidemic contributed to the end of the Pax Romana, a period from 27 BC to 180 AD, when Rome was at the height of its power. Subsequently, there were more wars and invasions by "barbarian" groups. Christianity became increasingly popular in the period following the emergence of the plague.No. of deaths: Over 5 million people% of global population: 2.8%

2. Plague of Cyprian: 250-271 AD

Named after St. Cyprian, a bishop of Carthage (a city in Tunisia) who described the epidemic as signaling the end of the world, it is estimated that the Plague of Cyprian killed 5,000 people a day in Rome alone. In 2014, archaeologists in Luxor discovered what appears to be a mass burial site of plague victims. Their bodies were covered with a thick layer of lime, lime being used as a disinfectant at that time. Archaeologists found three kilns used for lime production as well as the remains of the plague victims, who were burned in a massive fire.No. of deaths: unknown data% of global population: N/A

3. Plague of Justinian (Black Plague): 541-542 AD

The Plague of Justinian was a pandemic that primarily affected the Byzantine Empire but subsequently expanded, impacting the Sasanian Empire and port cities throughout the Mediterranean. At that time, merchant ships had rats on board, rats that were full of infected fleas. The plague had recurrences until 750 AD. Some estimates suggest that up to 10% of the world's population died. The plague is named after the Byzantine Emperor Justinian who reigned at the time. Justinian himself caught the plague but survived. However, his empire gradually lost territory in the period following the emergence of the plague.No. of deaths: 30-50 million people% of global population: 22.6%

4. Black Death: 1347-1351

The Black Death traveled from Asia to Europe, leaving a disaster in its wake. Some estimates suggest it wiped out more than half of Europe's population. It was caused by a strain of the Yersinia pestis bacterium that is likely extinct today and was spread by fleas to infected rodents and later transmitted to humans. The bodies of the victims were buried in mass graves. The plague changed the course of European history. With so many dead, labor became harder to find, bringing better wages for workers and the end of Europe's serfdom system. The lack of cheap labor may have also contributed to technological innovation. Protective measures against the disease were limited at that time, a situation different from the current context, where the population now has access to solutions involving protective equipment, quality medical services, and disinfectant products: hand disinfectants, surface disinfectants, biocide-based disinfectants.No. of deaths: 200 million people% of global population: 55.0%

5. Smallpox: 1520-1980

Smallpox, caused by the wild virus, produces a systemic rash after an incubation period of 10-14 days. After incubation, a systemic skin rash develops within 1-2 days: on the oral mucosa, face, extremities, and less so on the torso. Smallpox major has a 30% mortality rate, and smallpox minor has a 1% mortality rate. More than half of survivors are left with facial scarring. Over time, smallpox pandemics have caused over 500 million deaths. Smallpox is the first viral disease controlled through global vaccination. No. of deaths: Over 500 million people% of global population: 20.4%

6. Cocoliztli Epidemic: 1545-1548

The infection that caused the cocoliztli epidemic was a form of viral hemorrhagic fever that killed 15 million inhabitants in Mexico and Central America. In a population already weakened by extreme drought, the disease proved to be utterly catastrophic. "Cocoliztli" is the Aztec word for "pest." A recent study that examined DNA from the skeletons of victims found that they were infected with a subspecies of Salmonella that causes enteric fever, a category of fever that includes typhoid. Enteric fever can cause high fever, dehydration, gastrointestinal issues, and is still a major health threat. No. of deaths: Over 15 million people% of global population: 3.1%

7. Great Plague of London: 1665-1666

The last major outbreak of the Black Death in Great Britain caused a mass exodus from London, led by King Charles II. The plague began in April 1665 and spread rapidly during the hot summer months. Fleas from plague-infected rodents were one of the main causes of transmission. By the end of the plague, approximately 100,000 people, including 15% of London's population, had died. However, this was not the end of the city's suffering. In September 1666, the Great Fire of London began, which lasted four days and burned down a large part of the city, which implicitly resulted in the death of some of the black rats and fleas that carried the plague bacillus. The bubonic plague was known as the Black Death, and the symptoms of those infected were devastating: the skin had black spots and inflamed glands or "buboes" in the groin area, combined with compulsive vomiting, a swollen tongue, and headaches. The plague began in the East, possibly in China, and spread rapidly through Europe. Entire communities were destroyed and corpses littered the streets, as there was no one left to bury them.No. of deaths: 3 million people% of global population: 0.54%

8. Russian Plague: 1770-1772

In a plague-stricken Moscow, the terror of citizens in quarantine degenerated into violence. Riots spread through the city and culminated in the murder of Archbishop Ambrosius, who was encouraging crowds not to gather for worship. Empress Catherine II of Russia (also known as Catherine the Great) was so desperate to control the plague and restore public order that she issued a decree ordering all factories to be moved out of Moscow. By the end of the plague, up to 100,000 people may have died. Even after the plague ended, Catherine faced serious difficulties in restoring order.

No. of deaths: 360,000 people

% of global population: 0.045%

9. Philadelphia Yellow Fever Epidemic: 1800

Yellow fever is a viral disease transmitted through the bite of a mosquito, specifically the Aedes or Haemagogus spp. species. The pathogen is the yellow fever virus (YFV), an RNA virus of the Flavivirus genus, related to the West Nile virus, St. Louis encephalitis virus, and Japanese encephalitis virus.

When yellow fever took hold of Philadelphia, the capital of the United States at the time, officials wrongly believed that enslaved people were immune. As a result, abolitionists called for the recruitment of people of African descent to care for the sick. The disease was carried and transmitted by mosquitoes very quickly among the population, especially since it was a hot and humid summer in Philadelphia that year. Only when winter arrived – and the mosquitoes died off – did the epidemic cease. By then, over 5,000 people had died in that city alone.

No. of deaths: 100,000-150,000 people

% of global population: 0.014%

10. Sixth Cholera Pandemic (1817-1923)

Cholera is an infectious disease caused by a bacterium called Vibrio cholerae. The bacteria typically live in warm, salty waters, such as estuaries and coastal areas. People contract V. cholerae after drinking liquids or eating food contaminated with the bacteria, such as raw or undercooked shellfish.

Infected individuals experienced severe diarrhea, vomiting, and leg muscle cramps. These symptoms caused dehydration, septic shock, and even death in just a few hours. The first cholera pandemic emerged in India in 1817. It subsequently spread across several continents, devastating Asia, Europe, North America, and Africa.

No. of deaths: 1 million people

% of global population: 0.07%

11. Russian Flu: 1889-1890

The Russian flu was caused by the H2N2 influenza virus subtype, though evidence is not conclusive. In just a few months, the disease spread across the globe, killing 1 million people. It took only five weeks for the epidemic to reach a peak mortality level. The earliest cases were reported in Russia. The virus spread rapidly in Saint Petersburg before making its way quickly across Europe and the rest of the world, despite the fact that air travel did not yet exist.

No. of deaths: 1 million people

% of global population: 0.07%

12. American Polio Epidemic: 1916

A polio epidemic that began in New York City caused 27,000 cases and 6,000 deaths in the United States. The disease primarily affects children and sometimes leaves survivors with permanent disabilities. Polio epidemics occurred sporadically in the United States until the Salk vaccine was developed in 1954. As the vaccine became widely available, cases in the United States declined. The last case of polio in the United States was reported in 1979. Global vaccination efforts have greatly reduced the disease, although it is not yet completely eradicated.

No. of deaths: 60,000 people (in the US only)

% of global population: 0.003%

13. Spanish Flu: 1918-1919

The pandemic was caused by an H1N1 virus with genes of avian origin. It is estimated that 500 million people from the South Seas to the North Pole were victims of this virus, which caused the Spanish flu. One-tenth of them died, and some indigenous communities disappeared. The spread and lethality of the flu were exacerbated by the poor conditions of soldiers who were crowded together and had poor nutrition during World War I.

While the 1918 H1N1 virus has been synthesized and evaluated, the properties that made it so devastating are not well understood. Without a vaccine to protect against influenza infection and without antibiotics to treat the secondary bacterial infections that can be associated with flu infections, global control efforts were limited to non-pharmaceutical interventions: isolation, quarantine, good personal hygiene, the use of disinfectants and limiting public gatherings.

No. of deaths: 40-50 million people

% of global population: 2.4%

14. Asian Flu: 1957-1958

The virus that caused the pandemic was a mixture of avian influenza viruses; the disease was first identified in China and led to over 1 million deaths. The Centers for Disease Control and Prevention estimate that the disease spread rapidly and was reported in Singapore in February 1957, Hong Kong in April 1957, and coastal cities of the United States in the summer of 1957. The total death toll was over 1.1 million worldwide, with 116,000 deaths in the United States.

No. of deaths: 1.1 million people

% of global population: 0.04%

15. AIDS Pandemic and Epidemic: 1981-present

AIDS has caused approximately 35 million deaths since it was first identified. HIV, the virus that causes AIDS, likely developed from a chimpanzee virus that transferred to humans in West Africa in the 1920s. The virus made its way around the world, and AIDS was a pandemic by the end of the 20th century.

For decades, the disease had no known cure, but medications developed in the 1990s now allow people with the disease to experience a normal lifespan with regular treatment. Sex between men was the most common mode of exposure among people reported with AIDS (46%), followed by injection drug use (25%) and heterosexual contact (11%). Another factor for transmission was through blood transfusions and the use of infected needles.

No. of deaths: between 25 – 35 million people

% of global population: 0.5%

16. SARS (2002-2003)

Severe Acute Respiratory Syndrome (SARS) is a viral respiratory disease caused by a new type of coronavirus, SARS-CoV. The virus was first identified during an outbreak in China. Over the next few months, the disease spread across several continents, affecting countries in North America, South America, Europe, and Asia. SARS-CoV is transmitted through the air via respiratory droplets and through contact with contaminated surfaces. The disease causes fever, chills, body aches, and often progresses to pneumonia, a severe condition in which the lungs become inflamed and fill with pus.No. of deaths: 770 people% of global population: 0.00001%

17. H1N1 Swine Flu Pandemic: 2009-2010

The 2009 swine flu pandemic was caused by a new strain of H1N1 that emerged in Mexico in the spring of 2009 before spreading to the rest of the world. Within a year, the virus infected up to 1.4 billion people globally and killed between 151,700 and 575,400 people, according to CDC estimates. The 2009 flu pandemic primarily affected children and young adults, and 80% of deaths occurred in people under 65. A vaccine for the H1N1 virus that caused swine flu is now included in the annual flu vaccine.

No. of deaths: 575,400 people

% of global population: 0.008%

18. MERS: 2012-present

Middle East Respiratory Syndrome is a viral respiratory infection caused by a new coronavirus – MERS-CoV. MERS-CoV triggered an outbreak in Saudi Arabia in 2012 and another in South Korea in 2015. The disease infected camels before jumping to humans, triggering fever, cough, and difficulty breathing in infected individuals. MERS often develops into severe pneumonia and has an estimated mortality rate of approximately 35%. Most MERS patients developed severe respiratory illness with symptoms of fever, cough, and difficulty breathing. Approximately 3–4 out of 10 patients diagnosed with the MERS virus died. There is no vaccine available to prevent this disease. The best way to reduce the chances of infection is frequent hand washing, avoiding contact with camels, using hand disinfectants and avoiding the consumption of products containing raw milk from animals.

No. of deaths: 850 people

% of global population: 0.00001%

19. Ebola Epidemic: 2014-2016

The Ebola hemorrhagic fever epidemic in West Africa was an epidemic caused by the Ebola virus (EBOV), which belongs to the Filoviridae family. The epidemic began in December 2013 in Guinea. In the meantime, it spread rapidly beyond Guinea's borders, affecting Liberia, Sierra Leone, and Nigeria.

A smaller number of cases were also reported in Mali, Senegal, the United States, and Europe, according to the Centers for Disease Control and Prevention. There is no cure for Ebola, although efforts to find a vaccine are ongoing. The first known cases of Ebola occurred in Sudan and the Democratic Republic of Congo in 1976, and the virus may have originated in bats.

No. of deaths: 11,300 people

% of global population: 0.0002%

20. Zika Virus Epidemic: 2015-present

The Zika virus is a virus of the Flavivirus genus first identified in 1947 in the Zika tropical forest in Uganda. It causes Zika fever in humans, transmitted through the bite of a mosquito of the Aedes genus infected with this virus.

The impact of the Zika epidemic in South and Central America is not yet fully understood. Meanwhile, scientists are in a race against time to bring the virus under control.

Although Zika is not harmful to adults or children, it can attack the unborn in the womb, causing congenital malformations. The type of mosquitoes that carry Zika are found in warm and humid climates, making South America, Central America, and parts of the southern United States the primary areas for the spread of the virus.

No. of deaths: unknown data

21. Coronavirus disease 2019 (COVID-19)

COVID-19 is a respiratory disease caused by SARS-CoV-2, a coronavirus discovered in 2019 in China that spread rapidly around the world. The virus spreads primarily from person to person through respiratory droplets produced when an infected person coughs, sneezes, or talks. The virus is still present today, but it has undergone some mutations compared to the initial variant, which was much more severe and caused a large number of deaths in a relatively short time.

The emergence of the vaccine, the limitation of public gatherings, the observance of hygiene standards, as well as the use of disinfectants (hand disinfectants, surface disinfectants) have categorically contributed to the reduction in the number of cases.

No. of deaths: 6,367,793 people

% global population: 0.08%