10 of The Worst Infectious Diseases in The World

Bubonic Plague is one of the most devastating diseases of all times. In the middle ages, the disease caused an estimated 100 million deaths in Europe and 50 million deaths across the Roman Empire in the 6th century.

The disease is spread by a bacteria carried by rat fleas. After a bite, symptoms (initially swelling of the lymph glands) show up within 2 to 5 days. Other symptoms include seizures, cramps, blood vomiting, skin discoloration and extremities turning black.

In the final stages, the infected person may suffer extreme pain due to skin decaying. Bubonic Plague still exists and sporadic cases are reported even in the United States. However, it can be treated if antibiotics are provided within 24 hours, otherwise, the mortality rate reaches 60 percent.