10 Deadliest Pandemics of the Past Century

It’s hard to believe with all of the commotion on the news that we’re all still alive after all of the strife and hardship we’ve been put through. Diseases and pandemics seem like they’re a dime a dozen these days and it’s pretty difficult to separate the real threats from the fictitious ones. Sure, they can tag “pandemic” to the end of just about anything, but that doesn’t mean that it actually ruined the world. But if you look past all of the “minor” threats that were blown out of proportion in the past few years, you’ll see that in the past century some pretty deadly diseases came the way of the human race. Below you will find a list of the ten most deadly diseases and pandemics that have hit the world in the past century, how they came to be, and just how many lives they took. Let’s just hope that the next time a new flu strain outbreak is declared a “pandemic” it doesn’t wipe us all out! In no particular order, here they are.

The Spanish Flu


As World War I wound to a close an unusual strain of the flu virus started popping up in a remote area of Kansas in the United States. What started with just a few people getting sick eventually plagued the entire globe. It is estimated that over one billion people managed to contract the flu virus over its few year lifespan and while numbers are shady on the actual death toll, it is assumed that anywhere between twenty five million and one hundred million people were killed as a result. The Spanish Flu ended up claiming more lives than the war itself and has gone down as one of the most, if not THE most, deadly pandemic to ever hit the human race in terms of the number of people killed. But where did the name come from if the flu started in Kansas? Spain wasn’t involved in the war in any capacity and because of that, their newspapers were fairly free to cover whatever else came their way. When the flu struck, Spain was the only country with enough time to cover it without having to cover the war, thus The Spanish Flu.



One disease that never seemed to go away was typhus. It is still in existence today, but after a vaccine was developed during World War II, it has been confined to small regions of the globe where the vaccine just simply isn’t available. Typhus originated long before any of us can remember. During the Greek times Typhus struck Athens and killed a large portion of the population. As it died down and sprung back up throughout history, it has been the cause of many casualties in times of war and peace. The most recent outbreak of the disease was during World War I. During the war many Russian and Polish soldiers contracted the disease and died. With an estimated 40% mortality rate for those who catch it, it was not something you wanted to get. The name comes from a Greek word meaning “hazy.” If you contract the disease you will lose focus and your mind will become just that, hazy. Typhus killed almost three million people during the war and “stations” had to be erected for soldiers to clean themselves off during battle to keep the parasite away.


Cholera has its origins in the country of India. Sometime in the 1800’s the deadly disease found its way into the water supply where it continued to thrive. As the people of India all migrated to one city for a large festival celebration, many people contracted the disease from the water supply. While that happened over 200 years ago, cholera is still present in many of the water supplies around the world. Just 50 years ago a cholera outbreak happened in the Middle East and claimed about 30,000 lives. While it isn’t the most deadly disease out there, whenever a cholera outbreak strikes, because it’s in the water supply, it’s very difficult to stop.



A disease especially prominent in areas of the world where clean water supplies are unheard of, malaria is one of the most deadly diseases still present today. Mosquitoes find their way to sewage and dirty water so that they can live. They carry within them a parasite that, once injected into the blood stream, is difficult to stop. Mosquito bites inject the parasite into a human’s red blood cells and the cells help the parasite multiply and eventually kill. Estimates show that almost one billion people contract malaria each year around the world, most of whom live in impoverished areas of the world, and at least one million die from the disease. Children and pregnant mothers are especially susceptible to the disease as their immune systems aren’t strong enough to fight it off. There is a cure for this deadly disease, but because many people in the world do not have access to clean water or hospital care, curing them is very difficult and ultimately, they’re faced with death.


Smallpox is thought to have wiped out an entire population of native people in the Americas when it broke out. It is one of the deadliest diseases to come about in the 20th century. Smallpox, or Variola major, is a disease that causes severe skin ulcers and usually ends in death. With a mortality rate of about 30% for the people that contract it, smallpox became an epidemic in the mid 1900’s. It is estimated that smallpox killed over 60 million European citizens, including many heads of state. Once Europeans started migrating to the “New World,” they brought their diseases with them. Upon arrival, it’s thought that they brought smallpox with them and almost 95% of the native population in the Americas was eradicated. A campaign for a cure started in the middle part of the century and in 1979 the World Health Organization declared smallpox to be eradicated. It is the only human disease on record that has been successfully cured and eradicated.


It is still unclear where HIV got its start, but it is known how deadly the disease can be. Millions of people contract the sexually transmitted disease each year and many die. There is currently no cure for the disease and despite efforts by health organizations to cut down the number of infections worldwide, the numbers have continued to climb. HIV/AIDS was first discovered in 1981 and has since claimed approximately twenty five to thirty million people across the globe. Almost 70% of all people in the world with the disease live in Africa and the majority of those cases are women.



In terms of the number of people SARS killed, the numbers pale in comparison to other outbreaks. But in terms of panic and fear spread by the media and people across the globe fearing an infection, SARS quite easily has many other pandemics beaten. SARS came to be in the early 2000’s as severe acute respiratory syndrome. Its spread across the globe was caused by the ever changing world we live in. Because many of us are commuters, air travel played a huge role in the spread of the disease. What would have taken years in previous generations took only a matter of days or weeks to spread all around the world. SARS goes down in the record books as one of the fastest spreading diseases ever. Thanks to the World Health Organization and their teams of advisors, they were able to slow down the disease by performing extra flight checks and controlling the situation so more people didn’t die. Low death numbers in a pandemic are always a good thing.



Still one of the biggest concerns to health organizations across the globe, tuberculosis claims millions of lives each year. It’s estimated that someone contracts TB at least once every second somewhere on the planet. If left untreated, of those people that contract it, there is an 80% mortality rate. During the past century almost one hundred million people contracted the disease and died. At one point in time, during the early part of the century, one out of every six deaths caused in France was due to tuberculosis. There is a vaccine to prevent the disease but it must be administered at a young age to prevent infection later in life.


Leprosy has documented cases from at least before the birth of Christ and is still claiming lives. While there was no cure back then, the mortality rate from the disease is still fairly high today considering we have a method of prevention. If you contract the disease, there is usually a five to six year quarantine period where you will have to stay and be treated. Before there was a cure for the disease, leper houses were erected so that people with the disease wouldn’t spread it to others. Approximately 750,000 people contracted leprosy in 2002. Over two million die every year from leprosy.


The last entry on our list is measles. Through all of the combined cases around the world, measles has claimed more than two hundred million lives. In 2000, its death toll clocked in at around 777,000 people. The reason many people don’t ever hear about the disease infecting and killing people close to them is that measles is a disease that immunity can be built up against. If you are expose to measles in small doses you will eventually prevent yourself from catching it in the future. In smaller regions of the world, where the disease is still new and still rampant, contracting measles is a much easier feat. Before the vaccine that was introduced in 1963, millions of people got the disease each year in the United States.

Category: Disease and Conditions

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