Three plague pandemics in history caused about10.35 billion deaths. Plague is a serious infectious disease, once known as the Black Death, and all kinds of plague patients will die if they are not treated in time.

1, the first plague epidemic

It started in the middle of the 6th century and disappeared in the 8th century, killing hundreds of millions of people in Europe and Asia. The epidemic originated in the Sinai Peninsula of Egypt and broke out in Constantinople in 542. At that time, Constantinople was the most populous city in the world, with many caravans and fleets from Asia, Africa and Europe. Because the outbreak coincided with the reign of Byzantine emperor Justinian, this plague was called "Justinian plague" by later generations.

Its influence extends westward with the Mediterranean Sea, causing many countries and regions along the Mediterranean Sea to suffer from diseases, so it is sometimes called "Mediterranean plague". But people didn't know it was a plague at that time.

2. The second plague

Since the middle of14th century, the population of the European continent has decreased by one-third to one-half in the past 300 years. Europeans generally believe that the source of infection is brought by Mongols. The epidemic spread to France, Spain and Britain at 1348, to Germany and Scandinavia in the east at 1348 ~ 1350, and finally to the northwest of Russia at 135 1. Since then, the Black Death has invaded Europe many times in 15 and 16 centuries.

Plague epidemic lasted for nearly 300 years, covering Eurasia and the northern coast of Africa, especially Europe. Twenty-five million people died in Europe, accounting for a quarter of the European population at that time; Italy and Britain make up half of their population.

By August of 1665, 2,000 people died every week, and 8,000 people died a month later. It was not until a few months later that a fire destroyed most buildings in London and the rats disappeared that the plague epidemic subsided. This plague was called the "Black Death" by the epidemic in history. As a result, the whole European continent lost one-third to half of its population.

3. The third plague epidemic

From the end of 19 to the end of 1930s, more than one million people in the world died of plague.

It started in southern China and Mumbai, and finally gathered in the then Northern Manchuria area. Then came the plague in Shanxi, the second plague in Northeast China, and the plague in Europe, Asia and Africa, which did not disappear until after the 1930s. The epidemic has spread to more than 60 countries in Asia, Europe, America and Africa, and more than10 million people died of plague all over the world.

The epidemic spread quickly and widely, far ahead of the two pandemics. The characteristics of this epidemic are that the epidemic areas are mostly distributed in coastal cities and nearby densely populated residential areas, and there are also epidemics among livestock.

Extended data:

Symptoms and signs of plague

1, mild: irregular low fever, mild systemic symptoms, local lymph node swelling and pain, occasional suppuration, no bleeding, more common in the early and late epidemic or when vaccinated.

2. Glandular type is the most common type, which often occurs in the early stage of epidemic. Sudden chills, high fever, headache, fatigue, general pain, occasional nausea, vomiting, irritability, skin ecchymosis and bleeding. Flea bites the lymph node swelling and pain in the drainage area, which can be seen at the onset and develops rapidly, reaching the peak on the 2 nd to 4 th day. Inguinal lymph nodes are the most common, followed by axillary, neck and submandibular.

3. Lung type can be primary or secondary to glandular type, which is more common in epidemic peak. Pneumonic plague develops rapidly, with sudden high fever and obvious symptoms of systemic poisoning. A few hours after the onset, chest pain, cough and expectoration occurred, and the sputum quickly changed from a small amount to a large amount of bright red blood sputum. Dyspnea and cyanosis increase rapidly. Wet rales can be heard in the lungs, and breathing sounds are weakened. Signs and symptoms are often disproportionate. Those who were not rescued in time died of heart failure and shock within 2 ~ 3 days. Before dying, cyanosis is high, and the skin is often dark purple, so it is called the Black Death.

4, sepsis can be primary or secondary. The primary disease develops very fast, and systemic toxemia, central nervous system symptoms and bleeding symptoms are serious. Quickly enter unconsciousness, delirium or coma, and often die within 24 hours to 3 days after rescue.