5.1 Treatment of non-bacterial infections

Many of us already know that infectious illnesses are often caused by viruses or bacteria. But how many of us know actually what a difference that makes?

You'd normally need a microscope to explore the difference between viruses and bacteria. But studying things in a lab is not really my scene. I find it easier to explain stuff when I can get my hands dirty and see things properly. That's why I've come here.

The most obvious difference between viruses and bacteria is size. To us, a single bacterium might be pretty small, maybe a thousandth of a millimetre. But to a virus, they're looking fairly large. If we scale things up and took a typical virus to be the size of a suitcase, in which case a bacterium would be the size of a van.

And the comparison doesn't end there. Just like this van is a fully functioning machine with different working parts for specific jobs-- like wheels, engine, fuel pump, windscreen, etc. so too is a bacterium. It's a self-contained unit with a wall around it and all the biological machinery of a living cell.

Whereas a virus just has a thin protein coat, inside it's practically empty-- no machinery of its own, just a string of genetic material, like DNA. Like, in fact, an instruction manual. Alone, it can do nothing. It has to hijack a living cell and turn it to its own purposes.

It's only by using something else's biological machinery that a virus can repeatedly clone itself before bursting out and infecting countless more cells in a destructive chain reaction.

These essential differences mean that we have to use very different weapons for fighting viruses and bacteria. Of course, one big weapon in a doctor's toolkit or medicine bag is their antibiotics. There are several different types of antibiotics, and because they work in subtly different ways, it means they're a tremendously versatile drug.

What almost all antibiotics have in common is the ability to cripple a particular function of the bacterial cell. Now, there are many ways of doing this.

With so many parts to attack, antibiotics can disable bacteria in many different ways.

Whereas with a virus, there's nothing to disable. This is just the wrong tool for the job, which is why antibiotics are useless for viruses.

So unless you have a bacterial infection, there is no point your doctor prescribing antibiotics.

Nine times out of 10 with coughs and colds, it's a virus that's causing the problem.

Drugs to combat viruses work in a totally different way.

Most anti-viral drugs need to physically block the virus from getting into or out of the cell it needs in order to replicate. That should do it.