What are the more serious infectious diseases in human history?

/kloc-in the 6th century, before European explorers, colonists and conquerors entered the New World, there were nearly 65,438+billion aborigines living on the American continent. However, in the following year 100, the outbreak of infectious diseases drastically reduced the population to 5 million to100000.

Although some of them, such as the Incas and Aztecs, have started to build cities. However, due to the short time, they did not domesticate a large number of animals, nor did they breed many germs that invaded Europeans. However, with the arrival of European colonists, many infectious diseases that indigenous people could not resist also came to the New World.

Smallpox is the most serious of these infectious diseases. Smallpox has spread in human society for thousands of years, and the most serious disease will lead to 30% mortality. Symptoms of smallpox include high fever, body aches, rashes, blisters and permanent scars. This disease is usually transmitted by direct contact with the patient's skin or body fluids, but it can also be transmitted by air in a closed environment.

Extended data:

Smallpox is a serious infectious disease caused by smallpox virus infection, and it can be immunized for life after recovery. Smallpox is one of the oldest infectious diseases with the highest mortality. Highly contagious and seriously ill. People who have never suffered from smallpox or have not been vaccinated against smallpox can be infected, mainly manifested in severe viremia and high mortality after infection.

The most basic, effective and simple prevention method is vaccination. The clinical manifestations of smallpox are different, and the mortality rate of severe smallpox is about 25.5%. 45% of cases have a fused rash, and 79% have bleeding. The mortality rate of light smallpox was 0. 1% ~ 1.0%. Smallpox virus is a kind of poxvirus. The infected person has no specific medicine, and the patient will leave a pockmarked face after recovery.

The appearance of smallpox virus is brick, about 200 nm× 300 nm. Strong resistance, can resist drying and low temperature, and can survive on crusts, dust and clothes for several months to one and a half years.

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