Cholerae, a virulent intestinal infection caused by Vibrio Cholerae, was classified as a class A infectious disease in China.
The most typical symptom of cholera is diarrhea, followed by a massive loss of water and electrolytes, resulting in dehydration.
The patient's skin is dry and wrinkled, lacking elasticity, has a hoarse voice, sunken eyes and cheeks, and is delirious, eventually dying.
The epidemic is closely related to the process of urbanization. With urbanization and the expansion of city scale, the population of cities grows rapidly, and public health becomes a big problem.
There have been seven cholera pandemics in history, and the seventh, in 1991, was the most severe, affecting nearly 600,000 people in many countries.
The sewers and municipal water facilities that we take for granted today were not there at the beginning, but at the cost of countless lives.
Cholera and the dead in Broad Street, London, in the autumn of 1854
In the 1850s, a cholera outbreak in Chicago killed 60 people a day. Although the science of bacteria was not yet well developed, the City authorities made a decisive link between cleaning up the city and fighting the disease, because the city's filth and stench were obvious.
A man named Ellis Chesapeough was the chief engineer of the Chicago sewer system.
He solved the problem of the Chicago landscape being flat and impervious, and decided to build sewers deep underground.
During construction, Chesapebruff's team used screw jacks to raise an average of nearly 10 feet from one already built Chicago building to the next, then began building sewers within the raised 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 a sewer system
Eventually, Chicago became the first city in the United States to have an integrated sewer system, and other cities followed suit, planning to build underground sewer networks.
However, such a sewer system has a big drawback, is that the collected sewage does not have a good discharge point.
It ends up in the source of people's drinking water.
So the water environment was still very bad.
Only by finding a way to purify water can we fundamentally solve this problem.
And that's how, step by step, cholera came to be understood scientifically.
At first, cholera was widely believed to be caused by airborne pathogens known as miasmas.
It wasn't until John Snow, in his cholera-stricken London studies, made a statistical map of cholera deaths in Soho, that he was the first to show that cholera was caused by contaminated water rather than miasma.
John Snow Unfortunately, Dr. Snow died of a stroke four years later, and it wasn't until the 1870s, when Zeiss Optics, a German lens manufacturer, developed a new microscope that helped German scientist Robert Koch isolate vibrio cholerae from feces that the cholera problem was finally identified.
Since then, people have learned that bacteria that can't be seen by the naked eye can also be life-threatening.
Vibrio Cholerae
At the beginning of the 20th century, a water company in Jersey City was facing a flood of complaints about water quality and was considering replacing all of the city's water pipes.
However, a man named John Lear believes that it is essential to solve the problem of water purification.
After extensive experimentation, he dumped a modest dose of calcium hypochlorite into a Jersey City public reservoir.
The first large-scale chlorination of urban water supply in history was completed.
John Lear, who carried out the operation without prior government permission and without the knowledge of ordinary citizens, carried it out in secret, under great pressure and with great faith in science.
Although Lear rigorously controlled the dosage in numerous experiments, the fact that calcium hypochlorite was itself toxic made his behavior unacceptable to the general public.
Three months later, he was summoned to plead his case in court, and John Lear insisted that the practice would be widely adopted and that humanity would benefit.
Prosecutors eventually mocked him for seeking financial rewards through technological innovation.
Lear, however, has no patent on the chlorination technology, so any water company in the world can use it for free if it wants to provide "pure and sanitary" drinking water to its customers.
At last, the problem of clean drinking water was solved, and clean tap water was brought to the city, while the spread of infectious diseases like cholera was effectively controlled. The whole world owes a debt of gratitude to this reckless and great hero, John Lear.
Today, with such a comprehensive public health system, we have built one super-city after another, with tens of millions of people living and working together.
But cholera has not been eradicated as smallpox was.
In recent years, small-scale cholera outbreaks have continued with increased population mobility.
Particularly in parts of Africa with poor health infrastructure, coupled with war and unrest, cholera remains endemic.
Today, as human civilization is highly developed, we still have to have a little awe for this kind of humble and tenacious primitive life