Smallpox. More than 1 100 years ago, an acute infectious disease smallpox appeared in India or Egypt. Smallpox was prevalent in India and China from the 3rd century BC to the 2nd century BC. 165 to 180, the smallpox epidemic in the Roman empire,14 of the population died. In the 6th century, smallpox was prevalent in Europe, and 10% of the population died. In the17th and18th centuries, smallpox was the most serious infectious disease in Europe, with the death toll as high as10.50 billion. /kloc-In the middle of the 9th century, smallpox was prevalent in China, Fujian and other places, and the mortality rate exceeded 1/2. From 1900 to 1909, 500,000 people died of smallpox in Russia.

Plague. From 430 BC to 427 BC, there was a great plague in Athens, nearly 1/2 people died, and the whole Athens was almost destroyed. Some experts believe that this epidemic is a plague. The first world plague epidemic with clear records in history began in the 6th century, originated in the Middle East, and its epidemic center was the Mediterranean coast in the Near East. It lasted for nearly 60 years. At the peak, 1 10,000 people died every day, and the total number of deaths was nearly 654.38+billion. The most terrible thing is the plague epidemic in World War II, which was called the "Black Death" in history. 1348 ~ 135 1 spread rapidly in Europe, and the patient died within 3 ~ 5 days. In three years, the number of people killed reached 62 million (some say 30 million), and the population of Europe decreased by nearly 1/. 1348 at the peak of the epidemic, the death toll in Florence, Venice, London and other cities was over 65,438+million. The Black Death lasted until17th century. The third worldwide plague epidemic is the most extensive one. Plague broke out in Hong Kong from 65438 to 0894, and reached its peak in 1930s. It spread to more than 60 countries in Asia, Europe, America, Africa and Australia, and killed more than one million people. Among them, India is the most serious, with more than 654.38+0.02 million deaths in 20 years. The epidemic is mostly distributed in coastal cities and nearby densely populated residential areas. The epidemic spreads quickly and widely, far ahead of the two pandemics. Today, this plague is almost extinct in North America, Europe and other places, but it still appears from time to time in some parts of Asia and Africa.

Cholera. From the beginning of19th century to the end of 20th century, there were 8 large-scale cholera epidemics worldwide and several regional epidemics. 18 17 to 1823, cholera spread from Ganges delta in India, the hometown of human cholera, to Europe. Around 18 18, more than 60,000 people died in Britain. 1826 to 1837, the second cholera epidemic passed through Russia and successively reached Germany, Britain, Canada and the United States. From 1846 to 1863, the third cholera epidemic spread throughout the northern hemisphere. 1865 to 1875, the fourth cholera epidemic was triggered by a ship sailing from Egypt to Britain. From 1883 to 1896, cholera reached Egypt for the fifth time. 19 10 ~ 1926, the sixth cholera epidemic. The seventh cholera epidemic occurred in 196 1, which started in Indonesia and spread to five continents 140 countries and regions, with more than 3.5 million cases reported. 1992 to 10, the eighth cholera epidemic swept through parts of India and Bangladesh. In just two to three months, more than 654.38+million cases were reported and thousands of people died, and then spread to many countries and regions. 1Since September 1997, cholera has spread on a large scale in Africa. In the first three months of 1998, Uganda reported 1 1335 cases and Kenya reported10/08 cases.

Flu. 15 10, the first recorded influenza in the world occurred in Britain. 1580, 1675, 1733, there is a large-scale influenza in Europe. From 1889 to 1894, "Russian flu" swept the whole of western Europe. The most deadly is the1918 ~1919 influenza that swept the world. It may have originated in America. On March, 2008 19 1 1 day, the soldiers in an American military camp 107 first became ill. In less than two days, 522 soldiers were infected. Within a week, cases appeared in every state and spread all over the country for several months, but they were not taken seriously. In April, the flu spread to Europe, China and Japan. In May, the flu spread all over Africa and South America. The epidemic reached its peak in September. In June+10, 5438, influenza caused a record death rate of 5% in the United States. That year, nearly 65,438+0/4 Americans got the flu and 675,000 people died. About 20-50 million people around the world have died from this flu disaster. 18 months later, the disease mysteriously disappeared. The "Asian Influenza" of 1957 and the "Hong Kong Influenza" of 1968 have also spread to many parts of the world. The "Asian flu" caused 70,000 deaths in the United States, and the "Hong Kong flu" caused 34,000 deaths in the United States due to infection. The "Russian flu" from 1977 to 1978 began to spread in the former Soviet Union, and then spread to the United States and other countries.