How can the infectious diseases of human survival be effectively controlled? It has a lot to do with water!

The new crown virus caused by infectious diseases across the country, the country, all the people, all with one heart to resist the epidemic. This epidemic is mainly spread through air and contact. Is there any water borne infectious disease? It's a famous cholera.

Cholera is a kind of strong intestinal infectious disease caused by Vibrio cholerae, and it is classified as a Class A infectious disease in China. The most typical manifestation of cholera patients is diarrhea, and then, a large amount of water and electrolytes are lost, causing dehydration. The patient had dry wrinkles, lack of elasticity, hoarseness, orbital depression, deep concave cheeks, and unconsciousness, and died.

The epidemic is rampant and the urbanization process has a close relationship. With the urbanization and the expansion of urban scale, the population of the city has increased rapidly, and public health has become a big problem. In history, there have been seven cholera epidemics, of which, in 1991, that is, the seventh, the most serious, affecting many countries, with nearly 600000 patients. The sewers and municipal water facilities we used to today are not available from the beginning, but people pay countless lives to exchange for them.

Cholera and dead patients in wide street, London, fall of 1854

In the 1850s, cholera broke out in Chicago, which killed 60 people every day. Although the development of bacterial science at that time was not complete, the Chicago municipal authorities resolutely linked cleaning up the city with fighting disease, because the city's filth and stench were obvious.

A man named Ellis chesabruff was chief engineer in the construction of Chicago's urban sewers. He pioneered a solution to Chicago's flat and impervious landscape, and decided to build sewers deep underground.

During the construction period, chesaproff's team used screw jacks to raise an average of nearly 10 feet of built buildings in Chicago, and then began to build sewer pipes in the elevated space. Therefore, during the construction period, it did not have a great impact on the normal work and life of the citizens.

Chicago jacked up the city to build the sewer system

Finally, Chicago became the first city in the United States to have a comprehensive sewer system. Other cities followed suit and planned to build underground sewer networks.

However, such a sewer system has a big defect, that is, the collected sewage has no good discharge point. Finally, it was discharged to the source of people's drinking water. Therefore, the water environment of people was still very bad at that time. Only by finding a way to purify the water source can we fundamentally solve this problem. It is necessary to say that human understanding of cholera has entered the scientific level step by step.

At first, most people believed that cholera was transmitted through the air, which is called "miasma". It was not until John snow, who was suffering from cholera in London, drew the distribution map of cholera death cases in Soho district by statistical method. It was the first to prove that cholera was caused by polluted water rather than "miasma".

John Snow

Unfortunately, Dr snow died of a stroke four years later. Until the 1970s, Zeiss optics, the German lens manufacturer, developed a new microscope, which successfully helped German scientist Robert Koch isolate Vibrio cholerae from feces, and the cholera problem finally found the culprit. Since then, it has been understood that bacteria that are hard to identify with the naked eye can also be life-threatening.

Vibrio cholerae

At the beginning of the 20th century, a water company in Jersey City of the United States faced a large number of complaints about water quality problems. A man named John Lear thought that it was fundamental to solve the problem of water purification. After a lot of experiments, he put the appropriate dose of calcium hypochlorite into the public reservoir in Zexi city. Completed the first large-scale chlorination of urban water supply in history.

John Lear's action did not obtain the government's permission in advance, and ordinary residents were not aware of it. Relying on his belief in science, he carried out the operation secretly under great pressure. Although Lear strictly controlled the dosage after a lot of experiments, the fact that calcium hypochlorite itself is toxic makes his behavior unacceptable to the general public.

Three months later, he was summoned to defend his actions in court, and John Lear firmly claimed that this practice would be widely adopted and that mankind would benefit from it. In the end, prosecutors even satirized him for seeking economic returns through technological innovation.

However, Lear has not applied for a patent for this chlorination technology, so any water company in the world can adopt Lear's practice for free if they want to provide "pure and hygienic" drinking water for their customers. At this point, the problem of drinking water purification was finally solved. The city used clean tap water and effectively controlled the spread of infectious diseases such as cholera. All human beings should thank this reckless and great hero John lear.

Today, with such a complete public health system, we have built one super city after another, with tens of millions of people living and working together in peace and contentment. However, human beings have not completely eliminated cholera like smallpox. In recent years, with the increase of population mobility, small-scale cholera still occurs. Especially in some parts of Africa where the health infrastructure is poor, coupled with war and unrest, it is still a high incidence area of cholera. Today, human civilization is highly developed, we still have to have a trace of awe for this kind of humble and tenacious primitive life.