What is the principle of the sentence "There must be a great epidemic after a great disaster"?

After major disasters, such as waterlogging, the depth of accumulated water is too large and the time is too long, so that the air in the soil is discharged one after another, which leads to insufficient oxygen in the roots of crops, difficulty in breathing in the roots, and the production of toxic and harmful substances such as ethanol, which affects crop growth and even causes crop death, and is easy to breed bacteria.

Due to the serious breeding of bacteria, epidemics are generally caused by parasites, bacteria, viruses and other microorganisms. Therefore, it is often necessary to prevent the breeding of epidemics after major disasters.

Epidemic disease is an abnormal life activity process caused by self-regulation disorder under the action of certain etiology, which causes a series of changes in metabolism, function and structure of the body, showing abnormal symptoms, signs and behaviors. Epidemics occur in people, animals or plants, and are the general name of infectious diseases.

Extended data

Types of epidemic diseases:

There are 35 kinds of infectious diseases in China. According to the Law on the Prevention and Control of Infectious Diseases (in the traditional sense), the health administrative departments of the State Council and the State Council can decide the increase or decrease of infectious diseases according to their respective authorities.

1. Class A infectious diseases are also called compulsory management infectious diseases, including plague and cholera.

2. Class B infectious diseases are also called strictly controlled infectious diseases, including: viral hepatitis, bacterial and amebic dysentery, typhoid and paratyphoid, AIDS, gonorrhea, syphilis, polio, measles, whooping cough, diphtheria, epidemic cerebrospinal meningitis, scarlet fever, epidemic hemorrhagic fever, rabies, leptospirosis, brucellosis, anthrax, epidemic and endemic typhus, epidemic Japanese encephalitis and epidemic.

3. Class C infectious diseases are also called monitoring and management infectious diseases, including tuberculosis, schistosomiasis, filariasis, echinococcosis, leprosy, influenza, mumps, wind diagnosis, neonatal tetanus, acute hemorrhagic conjunctivitis, and infectious diarrhea except cholera, dysentery, typhoid and paratyphoid.

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