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One simple way to reduce the risk of infection is to maintain personal hygiene and to keep hospitals clean. In the 19th century, Ignaz Semmelweis realised the importance of cleanliness in hospitals. However, although his ideas were successful, they were ignored at the time because people did not know that diseases were caused by pathogens that could be killed.

Many types of medicines and chemicals have been developed to help prevent and treat diseases.

Antiseptics

Chemicals that kill microorganisms outside the body are known as antiseptics. Antiseptics can be used to clean an open wound as well as surfaces on objects such as toilets.

Antiseptics therefore help to prevent the spread of disease.

Antibiotics

Antibiotics are medicines that interfere with the growth of bacterial cells. This means that the bacteria die as they cannot reproduce. Antibiotics can therefore be used to treat bacterial infections such as Salmonella food poisoning and tuberculosis. Antibiotics will only kill bacterial cells. This means that these medicines will not work against fungi or viruses.

How some common antibiotics work

Penicillin

Since the discovery of penicillin, many other antibiotics have been discovered or developed. Most antibiotics used in medicine have been altered chemically to make them more effective and safer for humans.

Antivirals

It is often more difficult to develop drugs that can destroy viruses. This is because the virus infects a cell and hijacks the cell's machinery in order to create more copies of itself. Destroying the virus will often mean destroying the cell that the virus is inside of. Antivirals are drugs that stop viruses from replicating. They can be used to treat viral infections. Antivirals are often specific to one type of virus.