Epidemics. Also known as a widespread occurrence of an infectious disease in a particular time. There are quite a few epidemics that took millions of peoples lives. Starting from one country and spreading across the whole world. Some epidemics that took millions of peoples lives are The Plague of Justinian, The Black Death, The Spanish Flu, The Great Plague of Marseille, HIV/AIDS, Yellow fever, Malaria, and Ebola. URL of Source
The Plague of Justanian started around 541 and 542 AD. This plague spread through rodents due to the fleas they carried. The fleas were infected with the bacteria that killed roughly about 100 million people (half the world's population). These rodents would go on trading ships which helped the disease spread to other countries such as China, Northern Africa, and the Mediterranean. This plague weakened the Byzantine Empire. Their military lost power which meant that they were not able to stop intruders. Incoming taxes declined because of the decrease of agriculture base. URL of Source
The Black Death began in 1346 and ended in 1350. Just like the Plague of Justinian, this disease spread through rodents by infected fleas. The plague arrived in Europe in October 1347. 12 ships from the Black Sea stopped at the Sicilian port of Messina. People gathered around the ships and saw that most sailors on the ship were dead! For those who were still alive were barley breathing. They were seen as very ill looking and were covered in black spots that were oozing with blood and pus. Europe lost 60% of its population! And after 6-10 days of the infection, 80% of the infected people died. Since Europe was a Christian country, most of the people blamed the Jews. The Black Plague took many lives. Fun Fact, many people think the nursery rhyme, "Ring Around the Rosy" was about the Black Plague. https://www.history.com/topics/black-death
The Spanish Flu, also known as the 1918 Flu Pandemic, took many lives as well. It started in 1918 and ended in 1919. It originated during World War 1 in Camp Fuston, Kansas, U.S. Some people think is was caused by a virus while others think it was caused by a bacterium. This flu killed more people than the first World War. The flu spread by American troops. They arrived in Western Europe in April and spread to Poland by July. 550,000 people died in the U.S. only. All in all 50 million people died but most deaths occurred in second and third waves.
The Great Plague of Marseille began in 1720. The disease spread through a merchant ship called the Grand Saint Antoine. The ship carried infected passengers from the middle east. This was caused by none other than the infected flea carrying rodents. The rodents soon spread across the city which started an epidemic. A various amount of people were getting infected. Bodies would be thrown on the streets everyday. Provinces built "plague walls" to try and stop the plague from coming to them but it traveled on over to Southern France. It then disappeared by 1722 but it still killed 100,000 people. https://www.history.com/news/history-lists/6-devastating-plagues
HIV/AIDS is a very big deal. This disease is responsible for many deaths around the world. From young kids to adults. HIV/AIDS began in 1960 and is still going on. This disease caused the death of 39 million people. This disease came from a chimpanzee in West Africa. People do not actually die from AIDS. They die because of a weak immune system. What HIV/AIDS do when they enter your body is weaken your immune system which means if you catch something like pneumonia, your immune system will not be able to fight it off. When this disease first spread, ignorant people thought that only gay people could catch this disease. This caused many riots. This disease hit the gay population the hardest. In Africa 120,000 CHILDREN have died because of AIDS. Today, 37 million people are living with AIDS. http://www.theaidsinstitute.org/node/259
Yellow fever is caused by the bite of the yellow fever mosquito. This disease is mostly found on topical regions of Africa and America. This virus affects mostly humans and monkeys. The incubation is 3 to 6 days and about 15% lead to fevers. This disease has killed 600 million people. You can get vaccinated for this disease.
Malaria kills one child every 30 seconds. It kills about 3000 children every day. One million people die fro malaria each year. Malaria is also transmitted by malaria parasites. In the picture above, you'll see the life span of the Malaria parasite and what it does. Malaria began in Africa and spread from there. More than 40% of the world population live in malaria-risl areas. https://www.unicef.org/health/files/health_africamalaria.pdf
Ebola started in Africa and spread across the world. Many lives were taken because of this disease. Millions of African children and adults have died and still are dying beaus of ebola. The length time between exposure and development of symptoms are 2-21 days. Some symptoms are fevers, weakness, internal bleeding, decrease in appetite, and more. Being able to live with ebola is not likely to happen. Death follows 6-16 days. The first symptom is low blood pressure from fluid loss. In the picture above, it shows two nurses standing near patient Mayinga N'Seka with the virus in 1976. N'deka was a nurse who caught the virus after taking care of a nun who had flown in for treatment from the Yambuku Mission Hospital, where the virus began. https://en.wikipedia.org/wiki/Ebola_virus_disease
There were many devastating viruses that has been and still are in the world. Many lives have been taken. Hopefully there will not be anymore plagues like these due to our somewhat advance cures.