Sunday 25 March 2018

Is there no cure for the common cold?

Dr Aoife MacCormac The key to why antibiotics cannot be used for colds, but can be used for other diseases such as strep throats, lies in what causes the actual infection.

Bacteria are living organisms that are found everywhere. Most types of bacteria live in harmony with humans and some are even essential for human life (eg by helping to break down food in your gut).

However, some bacteria can make humans ill -- for example a strep throat or certain types of food poisoning. If you have a bacterial infection, the bacteria will divide by cell division and multiply in your body. This can lead to the destruction of your cells or the release of toxins which can cause illness. An antibiotic normally works by killing the bacteria and stopping their growth, for example penicillin interferes with the cell wall of the bacteria.

A cold is an infectious disease, that is a contagious disease spread by small biological agents known as pathogens. Colds are actually caused by viruses, the same troublemakers that cause many other diseases such as influenza and chicken pox.

Viruses are very simple pathogens that are much smaller than bacteria. They consist of some nucleic acid (DNA or RNA, the biological "instructions" for all living things) surrounded by a protein shell.

Viruses infect us by firstly "docking" onto our own body cells.

They then inject their own DNA or RNA inside the cells, and use them to make more copies of the virus. The cells will then burst and the new viruses will infect and destroy other cells.

Antibiotics simply do not work on viruses as they are completely different.

For example, a virus has no cell wall for penicillin to interfere with. There are anti-viral medications for certain infections that work in different ways, for example by preventing the virus from "docking" onto our cells.

However, the common cold is a complex disease that can be caused by many different types of viruses so it would be almost impossible to come up with a cure for them all.

The best thing you can do to prevent catching a cold is to keep fit and healthy and wash your hands regularly, especially if you have been out in public.

Irish Independent Supplement

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