Case study - John Snow and cholera
John Snow, a doctor, believed that A bacterial infection caused by contaminated drinking water. was spread in water and not by Smells from decomposing material, such as animal and human waste, that were thought to cause disease. In 1854 he got the chance to prove his theory was correct.
Cholera
The The process that transformed manufacturing from handmade to machine-made, mass-produced goods using water, steam and coal power transported by canal, rail and steamship. Britain was the first country to have an Industrial Revolution. saw a growth in the population of cities, such as London. The increased population led to overcrowding and more waste on the streets. This was coupled with a lack of proper sanitation or A series of underground pipes that take away waste water to be cleaned and re-used. for the growing populations. The first time that the disease cholera came to Britain was in 1831. Some people who caught it died in less than a day. Many people believed that cholera was spread by bad air and would try to prevent it by:
- burning barrels of tar to remove the bad air
- praying
- taking medicines that promised protection
- burning the clothes and bedding of victims
John Snow
When a cholera epidemic broke out in 1854, John Snow decided to investigate. His surgery was near Broad Street in central London, and hundreds of people around the area had died from cholera within ten days.
- Snow plotted each death on a map and proved that the people who had died all lived close to a specific water pump.
- He knew people used the water from the pump for drinking, washing and cooking.
- The handle was removed from the water pump so that it could not be used.
- As a result, there were no new cases of cholera or deaths from it in the area.
- Snow later discovered that a An underground pit used for collecting human excrement. close to the pump had been leaking waste into the pump鈥檚 water supply
By carrying out this experiment, Snow was able to prove that dirty water was causing the spread of cholera. However, many people continued to believe that disease was spread by bad air. This did not change until Louis Pasteur discovered bacteria. Snow had been correct, but he had not known that it was Single-celled microorganisms, some of which are pathogenic in humans, animals and plants. Singular is bacterium. in the water that was spreading cholera.