People have fought a variety of infectious, fatal diseases throughout human history. Even those diseases that are now entirely curable were once even more terrible before the 20thcentury discoveries in virology and medicines!
Even while these transmissible illnesses have been around from the time that humans were hunter-gatherers, things really started to deteriorate when people started to settle down.
Smallpox, influenza, TB, and other ailments first surfaced. We humans have persisted despite each outbreak of these diseases, though! And each time, our understanding of how to handle them grew as well.
Here are 9 fatal diseases that altered history and medicine for all time.
[NOTE: Non-communicable conditions like cancer, diabetes, and heart disease are some of the illnesses that claim the most lives. However, they have not been incorporated because they are not contagious.]
1. Bubonic Plague
The bacillus Yersinia pestis is the source of the deadly infectious disease known as the bubonic plague. It has existed for centuries and is sometimes referred to as “The Black Death” and “The Pestilence.” The first recorded case of it was the Plague of Justinian, which occurred between 541 and 549 AD.
Infected fleas or small mammals like rodents can spread the Y. pestis bacteria, which can then infect people when they are bitten or scratched.
Despite being widespread, since the bacteria was identified in 1894, scientists have quickly devised methods of treating it and stopping its spread, and it is now generally treatable with things like antibiotics!
The Black Death (1346–1553) inspired the creation of public health measures like quarantines, the isolation of sick people, and the use of protective clothes for doctors.
2. Influenza
Influenza, usually known as the flu, is a serious illness that affects the respiratory system and is brought on by a variety of influenza viruses.
Although there may have been influenza outbreaks as far back as 6,000 BC, the earliest instance of an epidemic of the respiratory disease we now know as influenza was documented in writing for the first time in 1510.
While some varieties of influenza are caused by humans, influenza pandemics often occur when a novel strain of the virus is transferred from one animal species to humans, particularly an animal that we eat (like pigs, chickens, or ducks).
The flu’s mild to severe symptoms typically include fever, runny nose, sore throat, muscle aches, headaches, coughing, and fatigue.
3. Cholera
Some strains of the bacteria Vibrio cholerae are more dangerous than others and all of them induce an infection of the small intestine that is fatal.
Typically, it causes dehydration and mortality as a result of vomiting, cramping in the muscles, and severe watery diarrhea.
Beginning in 1817 in the Bengal region of India, cholera has existed for centuries and is considered to have its origins in the Indian subcontinent. Since then, it has caused seven significant pandemics.
People can get sick from the bacteria by drinking contaminated water that has been tainted with human feces. Sadly, cholera still claims the lives of 50,000 to 120,000 people year.
Dr. John Snow first realized the significance of clean water for public health and epidemiology—the study of how infectious illnesses spread—after a cholera outbreak in London in 1854.
4. Smallpox
Thank goodness, smallpox has been fully eradicated thanks to vaccine, so we don’t hear about it anymore. However, it used to be one of the most deadly illnesses for people! Its symptoms, which included fever, vomiting, skin rashes, and blisters, were brought on by the Variola virus.
Although it has been present for generations and we don’t know where it came from, the first significant epidemics were in 18th-century Europe.
Although ancient Chinese and Indians attempted to utilize various techniques to immunize against smallpox (such as pressing diseased scabs or fluid into scratches made on a healthy patient in the hopes of establishing immunity!) Edward Jenner created the first iteration of what we now refer to as a vaccination only in 1798.
Around 500 million people died from smallpox in just the 20th century alone, and the development of this vaccine has made a significant contribution to the fight against the illness.
5. Typhus
This condition, which is often referred to as typhus fever, is actually a collection of infectious illnesses such as epidemic typhus, scrub typhus, and murine typhus, all of which are brought on by bacteria that are transmitted by mites, fleas, and lice. Its signs include a rash, fever, and headache.
Typhus has probably existed for a very long time, but the first instances were recorded in 1489 AD. However, there have been other epidemics throughout history, most of which began in crowded, unhygienic locations.
Fortunately, it is now quite uncommon and is curable with drugs like doxycycline.
6. HIV/AIDS
The virus that causes AIDS, or acquired immunodeficiency syndrome, known as HIV, was first discovered in 1981 and is thought to have originated in African chimpanzees before being transmitted to humans in the early 20th century.
Since its initial discovery in the Democratic Republic of the Congo in 1976, the illness has gone untreated for many years.
But today, thanks to modern medications, HIV is a much more controllable chronic illness. In fact, the number of individuals dying each year from HIV/AIDS decreased from 2.2 million to 1.6 million globally, and as of early 2020, two people had even been cured of the virus!
7. Dengue Fever
The dengue virus, which is responsible for the tropical disease dengue, is dispersed by mosquitoes, particularly the Aedes aegypti species.
Although it frequently results in high fever, hemorrhagic bleeding, and death, it can also cause symptoms including high fever, headache, vomiting, muscle and joint problems, and a skin rash.
Fortunately, there is now a dengue vaccine, and antiviral medications are being created to treat it.
Although dengue fever episodes may have existed as early as the fifth century AD, the first record of an epidemic that raced through Southeast Asia, Africa, and North America dates to 1779. Cases remained uncommon after then till the end of the 20th century.
But because of ecological disruption, they have increased in frequency.
8. Malaria
Malaria is another infectious disease caused by mosquitoes, like dengue, and is carried by the Anopheles mosquito.
Fever, exhaustion, nausea, and headaches are some of its symptoms, along with yellow skin, convulsions, coma, and death in severe cases. It is brought on by the malaria parasite.
If a sickness isn’t adequately treated, a person may occasionally experience recurring symptoms months or even years down the road!
There are numerous drugs available now that can both prevent and treat malaria. Even better, a vaccine that can cut your chance of contracting malaria by 40% was created in 2020!
9. Coronavirus
The coronavirus that causes COVID-19, also known as SARS-CoV-2, was initially discovered in bats in December 2019 in Wuhan, the capital of China’s Hubei province. It has since spread all over the world.
A vast group of viruses known as coroviruses frequently cause respiratory infections. They can range in severity from moderate to severe, and their symptoms might include fever, exhaustion, a dry cough, and a loss of smell.
The COVID-19 virus is primarily spread by droplets produced when an infected person coughs, sneezes, or exhales.
While COVID-19 does not have a specific treatment, there are numerous management options, including oxygen support, antivirals, and — most importantly — vaccines.