Worst Pandemics in History in the Last 100 Years

1. Antonine Plague

The Antonine Plague (165 to 180 AD) took place during the time of the Ancient Roman Empire. It was a pandemic that spread across the empire – from Gaul (present-day France) to the city of Seleucia (now known as Baghdad).

It’s not known what the disease was, but from descriptions of the symptoms from historical sources that included fever and skin eruption or rashes, scholars suspect that it was either smallpox or measles [1].

Whatever it might have been, it was likely spread by Roman troops who were returning from campaigns in the Near East. 

In either case, if it were smallpox or measles, it would be one of the few known cases of those diseases being spread so far and wide, as through history there have been more localized outbreaks and epidemics [2][3] [4]

2. Plague Pandemics

The plague is an infectious disease caused by the Y. pestis bacteria. It is spread by small mammals and the fleas that live on them. It has been around for centuries and has caused a number of outbreaks throughout history.

In total, there are three kinds of plague (all caused by the same bacteria) – bubonic, pneumonic, and septicemic, though the most widespread has been the bubonic type.

While some have been small outbreaks or local epidemics, most of them have since been classified as part of one of the three great world pandemics that started in 541, 1346, and 1855. [5]

3. Cholera Pandemics

Cholera is a disease caused by strains of the bacterium Vibrio cholerae. It’s spread through food or water that is contaminated by fecal matter, which makes it possible for the disease to quickly travel over long distances.

It has been the cause of seven major pandemics throughout history, the last ending in the 1970s. Since then, there have been smaller outbreaks usually after the war, civil unrest, or natural disaster, when food and water become contaminated due to crowded living conditions, and resources are scarce. [6]

4. Influenza Pandemics

Commonly known as the “flu”, influenza is a highly contagious disease caused by several related viruses. It attacks the respiratory system, and its effects can range from mild to severe.  

Some types of influenza are endemic (or come from) humans, but these types are often not as severe as those that come from other animal species (like pigs or chickens).   

There have been six influenza pandemics in the last 150 years alone, and of these, the 1918 flu pandemic (also known as the “Spanish flu”) was the most severe. [7]

5. HIV/AIDS

This condition is one that affects the immune system, and increases the risk of developing other serious infections. It is known as AIDS (or “acquired immunodeficiency syndrome”) caused by HIV (the “human immunodeficiency virus”).

It was first identified in 1981, and for decades the disease had no cure, and spread across the world through unprotected sex, contaminated blood transfusions or needles, and from mother to child during pregnancy. It has infected millions of people and is still ongoing.  

However, there is a silver lining, as new antiviral treatments have made AIDS a more manageable chronic health condition. [8]

6. SARS

This pandemic involved a respiratory disease known as Severe Acute Respiratory Syndrome (SARS). The disease was caused by a type of virus known as the “severe acute respiratory syndrome coronavirus” (SARS-CoV). The virus was spread through respiratory droplets. 

The outbreak first started in China on 16 November 2002, and from there,  it spread to 30 countries around the world. It lasted about 18 months before it slowly diminished, and by May 2004, no cases were being reported. [9]

7. MERS

Another viral respiratory infection caused by a coronavirus is the Middle East Respiratory Syndrome (MERS). The virus responsible is known as Middle East Respiratory Syndrome-related coronavirus (MERS-CoV).  

While the virus is believed to have originated in bats, humans began to be infected from contact with camels. It also spread through contact with an infected person.

While cases of MERS have been seen worldwide since the initial outbreak in 2012 (classifying it as a pandemic), it is uncommon outside of hospitals making both confirmed cases and deaths quite low in number. [10]

8. Ebola

Ebola, also known as Ebola virus disease (EVD), is a type of viral hemorrhagic fever caused by ebolaviruses.  It was first identified in 1976 in Sudan and the Democratic Republic of the Congo at a village near the Ebola River.  

Since then, there have been numerous outbreaks across sub-Saharan Africa. However, the only one that spread throughout West Africa and even crossed borders (making it a pandemic) lasted from December 2013 to January 2016. [11]

9. Zika

Zika (also often known as Zika fever, or the Zika virus disease) is an infectious disease caused by the Zika virus. The virus is spread by mosquito bites, sexual transmission, and blood transfusions and is especially harmful to pregnant women and their babies.  

In other adults, most cases resemble a mild fever or show no symptoms. The virus was first identified in 1947, and since then there have been a few outbreaks in tropical Africa and in some areas of Southeast Asia.

However, in early 2015, there was an outbreak of Zika fever in Brazil that spread to other parts of South and North America and eventually affected several islands in the Pacific and Southeast Asia. This pandemic ended in November 2016. [12]

10. COVID-19

COVID-19 is a type of viral respiratory infection caused by a coronavirus (known as SARS-CoV-2). Cases were first reported in Wuhan in China in December 2019, and since then it has spread around the world, becoming one of the deadliest pandemics in history. 

It is mainly transmitted through respiratory droplets, though there is also evidence that it is airborne. As of yet, there are no specific vaccines or medicines for COVID-19. However, we do have vaccines and some specific drug treatments to manage the symptoms and eventually help slow down the spread of the virus. [12]