What is flu?

Flu can prove fatal in those weakened by age or other illness

Hundreds of thousands of UK people will fall ill with flu over the next couple of months - and some will not survive.

Many people confuse viruses which cause cold-like infections with the influenza virus, which generally causes a far more severe infection.

A virus is essentially a microscopic bundle of genetic material, or DNA, enclosed in a coat made out of body chemicals called proteins.

Viruses which cause illness are able to enter human cells, and there harness the contents of the cells to replicate - making many copies of itself.

Eventually, the cell bursts and a large number of viruses are released into surrounding tissue, to infect other cells.

Although cold and flu infections may have similar features - sometimes having a very severe cold may feel like having a very mild case of flu.

Symptoms

However, in general, cold victims will suffer the following symptoms.

• A scratchy, sore throat
• Blocked or runny nose
• cough

And flu sufferers can expect at least some of the following:

• Spells of high fever (perhaps above 101 degrees Farenheit)
• Severe muscle aches and pains
• An illness which flares up far quicker than a cold - and lasts longer at its peak

In basic terms, if you have flu you are likely to feel a great deal worse than if you have a simple cold.

Sufferers speak of simply not being able to move around the house because they are feeling so drained.

The virus is passed from person to person in a variety of ways.

If you are sneezed or coughed on by someone with the flu virus, the droplets which land in your eyes, or whch are breathed in are likely to carry it.

Many people are confused about the best way to treat flu.

One thing is certain - antibiotics do nothing to help the symptoms or length of a flu infection. They cannot kill viruses.

However, one thing the virus can do is weaken the person, who then falls prey to a secondary infection, such as pneumonia - which can be life threatening.

At this point, antibiotics need to be given quickly to prevent the bug taking hold.

About 20% of those who need treatment for pneumococcal infection die - about 40% of the elderly, very young or immunosuppressed.

Rest advice

For everyone else, however, there is only advice on how to lessen the symptoms.

Doctors advise patients to:

• Take paracetamol to treat the aches and pains, and reduce the high fever
• Treat the cough with some sort of linctus, or hot, sweet fruit drinks, such as hot lemon with honey
• Increase the amount of drinks taken, to ward off dehydration
• Steer clear of smoking or smoky atmospheres
• Take plenty of bed rest - this could protect other people from the spread of the virus

Doctors say there is little they can give apart from this advice to ease the suffering of the young normally healthy adult.

Relenza can cut short flu infections

They have urged such patients not to clog up their surgeries, as there may well be more vulnerable flu victims who need attention.

Viruses have proved remarkably resistant to much of medical science's efforts to tackle them.

In the case of flu, Relenza, an inhaled powder, has been developed to inhibit the replicating ability of the virus.

It appears to be able to cut the length of a flu infection by a few days, although it cannot wipe out the virus altogether.

And it is not certain whether it could help those patients most at risk from flu - the elderly, the very young or those sick with other conditions.