It is not the first time in history that nations are fighting an epidemic but the world has been a victim to several deadly pandemics in the past causing a threat to life and civilization. Here are some of the worst epidemics that have brought focus on public health and safety with nations gearing up its fight against such diseases. Justinian's Plague If you go back to 542 AD, then one of the oldest epidemics that killed millions remains Justinian's Plague. It was one of the deadliest outbreaks that first emerged in Constantinople as plague-ridden fleas thrived on black rats that munched on the grains brought from Egypt.  The deadliest pandemic continued to create havoc in Mediterranean region for the next 225 years before vanishing in 750 AD. Black Death The next epidemic which again took the world into depression was Black Death. It seemed that the earlier plague never disappeared as it made a comeback in Europe in 1347. The disease went on to kill almost 200 million in four years. This disease has several names from Pestilence, the Great Bubonic Plague, the Great Plague or the Plague, besides the Great Mortality or the most popular Black Plague. The bacteria Yersinia pestis, which was also the culprit behind Justinian’s plague has wiped out a large number of the population and lasted till 1351. It is said that the Black Death originated in Central Asia or East Asia before reaching Europe through trade routes. It is interesting to note that the term quarantine first came into the picture around this plague. It is because sailors were asked to remain within the ships for 30 days, which was popularly known as trentino in Venetian law. The sailors were sometimes forced to extend their stay up to 40 days or quarantine, which led to the practice and termed the move as quarantine in the Western world.   The Great Plague of London The next epidemic which took control over human lives was The Great Plague of London. This time in 1665, London came under the grips of the pandemic which lasted a year. However, the scale of the pandemic was smaller as compared to Black Death but considered a worst one as it was the last widespread outbreak of bubonic plague in England.  It took the lives of more than a lakh people, almost a quarter of London's population.

Smallpox

The disease has claimed lives in Europe, Europe, Asia, and Arabia for years. The disease used to leave scars on the body but the number of death in older times were much lower compared to the deaths after it appeared in the 15th Century. Smallpox is caused by infection with the variola virus and the disease used to claim the lives of three out of 10 people who got infected. However, around the 18th-century, a British doctor named Edward Jenner found a cure through vaccination. He found that a milder virus called cowpox can be used in treating the disease

Cholera

It has initially surfaced in England around 19th century killing a huge population. It was then said that the disease spread through foul air called “miasma.” However, later Cholera was studied and found to be an acute diarrhoeal infection caused by the ingestion of food or water contaminated with the bacterium Vibrio cholera. Later Tuberculosis also emerged as a deadly disease. The evidence of tuberculosis in humans dates back to 2400-3400 B.C, where evidence of the disease was found in the spines of mummies. Similarly, several diseases have afflicted the human race much before the start of civilization. Some of the modern day epidemic also includes Asian Flu, Hong Kong Flu , HIV/AIDS, the SARS epidemic in 2005-6 and Ebola which spread in Africa in 2014. Even as the world is fighting the novel strain of SARS, it is hoped that the scientific community comes up with vaccination to immune the human race against the deadly disease.