The human population has been thinned out by terrible diseases countless times in history. Millions of people have been wiped out by various diseases in the past several hundred years. Throughout our history, people have been ravaged by diseases that were brought on by a number of different factors. Sometimes the source of the disease was an animal or an insect. At other times, just a single human being. Whatever the cause, the 10 diseases on our list below have caused millions of deaths throughout human history.
1. Black Death
The Black Death is thought to have caused as many as 75 million deaths in the middle ages. It is thought that this dreaded disease started in Central Asia and was brought to Europe in the 1340s. About 25 million people died in Europe, and it is believed that the disease killed as much as 2/3 of the population of Europe. It is now believed that the Black Death was caused by a type of flea that is carried by rodents. Lack of proper sanitation is probably the major cause of the spread of the Black Death, or the Black Plague.
Poliomyelitis (polio) is a viral disease of an acute nature that spreads between human beings. It seems to spread by the fecal/oral route primarily. About 90% of polio infections do not result in any symptoms. The problems occur if the virus gets into your blood stream, which then attacks the central nervous system in a small minority of cases. If it does, it will infect and damage motor neurons, which leads to weakness of muscles and paralysis in some cases. About 10,000 deaths have resulted from polio, but hundreds of thousands were paralyzed, including President Franklin Roosevelt, before a vaccine was discovered.
Smallpox has ravaged human populations many times in history. It is thought that smallpox reduced Native American populations from 12 million to 235,000 in the 17th century. Smallpox is brought on by two viruses: Variola major and minor. The deadlier form is Variola Major and it causes about 35% of those infected to die. Even if you do not die from smallpox, you will be scarred for life. Also, some people go blind due to ulcerations of their corneas. Smallpox is thought to have killed 60 million Europeans in the 18th century. Fortunately, smallpox is one disease that has been completely eradicated throughout the world.
Cholera is a diarrheal disease that is brought on by the Vibrio cholerae bacterium. It is usually transmitted to people by the ingestion of water or food that has bee contaminated. Cholera is a very deadly disease, and a person can actually die within a few hours if there is no treatment. Usually, the disease will start with diarrhea, to shock, and then death in a few days if no treatment is given. About 12,000 people have died from this disease in the last 20 years.
This virus first began in 1976 when there were outbreaks in Zaire and Sudan. It is thought to be a zoonotic virus that is causing problems today with the gorilla population in Central Africa. No one is sure what the exact source of the virus is, but there are theories that the fruit bat is responsible. Someone who is suffering from the Ebola virus can have fever, vomiting, diarrhea, pain and bleeding. Mortality is up to 90% of those infected. About 160,000 have died in the last decade from Ebola.
Malaria is one of those diseases that is still ravaging the world. Believe it or not, more than 2.7 million people die from malaria every year. This is a disease that is carried by mosquitoes and is caused by a protozoan parasite. It is very common in tropical and subtropical parts of Africa, Asia and the Americas. It infects about 500 million people each year and kills several million per year. Malaria is one of the most serious public health problems in the world. No vaccine is available for this disease, but there are some drugs that you can take constantly to reduce your risk.
7. Spanish Flu
This was what caused the 1918 flu pandemic, and it was a category 5 influenza pandemic. Many victims were healthy young people, rather than the old and young, as is typical with flu outbreaks. This pandemic lasted from 1918-19, and spread even as far as the Arttic and to remote islands in the Pacific. It is believed that more than 50 million died, which might have made it more deadly than the Black Death. This very high death count was due to the high rate of infection of as high as 50%.
The common flu is a disease of mammals and birds that is brought on by RNA viruses that belong to the family orthomyxoviridae. While many cases of influenza are not deadly, in serious cases, it can cause pneumonia, which can be very serious in young and old people. Flu is unrelated to the common cold and is a much more serious disease. The common flu causes 36,000 deaths each year.
AIDS is an assortment of infections and symptoms that happen because of damage to the immune system caused by HIV. The later stages of this disease leave the victim very vulnerable to infections and various tumors. It is thought that HIV started in Africa in the 20th century. About 40 million people around the world currently have HIV, if not full blown AIDS. Fortunately, drugs have been developed that can at least help to ward off HIV from turning into the full AIDS disease. Still, no vaccine has been found yet to fully cure this disease.
One does not hear as much about tuberculosis, but it is still a killer. More than 3 million per year still die from TB around the world. Luckily many of the people infected never have any symptoms, but about 10% do eventually develop TB. Over a few months or years, TB slowly destroys your lungs, and eventually you can spit up blood. Fortunately, like the Black Death, TB is treatable with antibiotics. It still can take a few months to clear up this nasty disease with proper treatment, however.