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The fight against disease

Watch to recap the work of Pasteur and Koch before finding out more about their work.

Up to the 1860s, beliefs about the causes of disease were still based on ancient ideas, such as Louis Pasteur鈥檚 discovery of germ theory would revolutionise medicine.

Spontaneous generation

Doctors were aware that germs existed in the late 17th century. However, there was not a belief that germs caused disease. People believed in This led to the belief that germs, which appeared at the site of disease or illness, were a consequence of the illness rather than the cause of the illness.

What did Louis Pasteur do?

A swan neck flask. There are two glass tubes coming out from the top of the flask, one of which bends downwards to the table and then up again.
Figure caption,
A swan neck flask, similar to the ones that Pasteur would have used in his experiments

Louis Pasteur was a French chemist. In the 1850s, he was asked by a French winemaker to investigate why their wine was going off. Pasteur used a to see that there were a type of in the wine. He believed this was what was making it go off. He successfully heated the wine to kill the bacteria.

Pasteur carried out further experiments to prove his theory. He put some broth in two swan neck flasks and boiled it, which killed any microbes that were already there. He then broke the neck off one of the flasks. The flask that was exposed to the air went bad, but the sealed flask did not. This further proved Pasteur鈥檚 theory that microbes were in the air and caused disease in humans.

In 1861 Pasteur published his work on germ theory. This was a hugely significant moment. It allowed further advances to take place in surgery and

What did Robert Koch do?

Robert Koch was a German doctor. He used industrial dyes to stain bacteria. This made them easier to identify when viewed under a microscope. In 1876, he identified the germ that causes anthrax. This was the first time the bacteria responsible for a specific disease had been identified. Identifying specific bacteria was crucial in being able to develop effective treatments and vaccines.

Pasteur and Koch were rivals, but their work led to significant advances in medicine.

The chicken cholera vaccine

In 1879, Pasteur was working with his assistant, Charles Chamberland, to try to find a cure for chicken cholera. They were injecting chickens with cholera germs and then trying to cure them.

On returning from holiday, Chamberland injected a chicken with cholera germs. It did not become ill. Pasteur told Chamberland to try again with fresh germs but the chicken still did not become ill. Pasteur realised that the old germs had caused the chicken to develop to cholera. This meant that he and Chamberland had discovered a vaccine by chance.

This would lead to further vaccines quickly being discovered (eg for anthrax and ). Unlike Jenner, Pasteur understood why his vaccine had worked, so he could replicate the process for other diseases.

How did the fight against disease develop?

Timeline showing key developments in the fight against disease throughout the 19th century

Which factors helped Pasteur and Koch?

Pasteur and Koch were helped by various factors:

  • Technology - Koch鈥檚 assistant, Julius Richard Petri, invented the This enabled Koch to grow bacteria. He could then use industrial dyes to stain the bacteria. Finally, he could use powerful microscopes to identify the bacteria.
  • Chance - Pasteur developed the chicken cholera vaccine when he left some cholera germs unrefrigerated before going on holiday. When his assistant, Charles Chamberland, injected these germs into a chicken on their return, the chicken did not become ill. Pasteur realised that the old germs had given the chicken immunity without making it ill.
  • War - In 1870-1871, France and Germany were fighting each other in the Franco-Prussian War. This led to rivalry between Pasteur and Koch. Their respective governments invested in their research to show they had more advanced science and for national pride.
  • Key individuals - Pasteur and Koch are both significant figures in the fight against disease. Their work relied on careful observation, scientific experiments, and years of work to develop new methods and treatments.