Now you know: What is influenza?


If there’s one illness that never seems to go away, it’s the dreaded flu – which can range from being unpleasant to deadly

Susan Ramsay |

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Three people have died this year of influenza or “flu” as it is known, the latest being earlier this month. But 2018 is also the 50th anniversary of the Hong Kong flu, which claimed a million lives as it spread through the world.

What is flu?

Influenza – so named because in the past people thought that those who caught it were under the “influence” of an unlucky pattern of the stars. Today, though, we know it’s caused by the virus in the picture below.

Different kinds of flu viruses affect different animals, including humans. And these forms of the virus change each year, so there is always some or other type of flu going around.

How it spreads

The flu virus, like many others, is spread though contact with the virus. When someone who is infected coughs or sneezes, the virus is sprayed, almost like a deodorant spray, and hangs around in the air that others breathe in.

It also settles on surfaces, so that when people touch those surfaces they carry to virus further or become infected themselves.

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Cold or flu?

The common cold is also a virus that infects people. Its symptoms are very similar to those of the flu, causing a runny nose, a sore throat, a fever, and coughing. These are all the body’s natural response to fighting and
clearing the virus.

The flu is not necessarily worse than a common cold, but some types of flu will be. Like we said: flu can kill.

How to know if things are bad

If you are struggling to breathe, you need to see a doctor. Other signs that you need medical attention are vomiting, chest pain, feeling very tired, a fever or a rash, or if your fingers are turning blue. If the symptoms disappear and then come back bringing a high fever and a nasty cough, you also need to visit the doctor.

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How to protect against flu

Each year the World Health Organisation tries to predict which strains will be the most dangerous during the year. It then sends out vaccines and notices to governments, telling them who will need the vaccines most.

It is not usual for these vaccines to be recommended for young people as their immune systems should be able to cope. However, often adults who work like to take the vaccine so that they won’t be badly affected if they do catch it.

How to prevent flu spreading

You will have noticed that in housing estates, or even at school, cleaners regularly go around wiping lift buttons, door handles, and other surfaces likely to be touched by a lot of people.

You also need to do your part by washing your hands to wipe away any bugs that you pick up like after you go to the toilet. You can’t just rinse your fingers under water and think that’s good enough. You need to use soap – because soap breaks down the virus – and lather it over your hands and wrists for 20 seconds!

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Why everyone gets freaked about flu

Like we said, flu kills. But in the past it killed millions of people. In the Spanish flu epidemic of 1918-1919, between 25 million and 50 million people died. This was in part due to the fact that there was a war on and large numbers of people were moving to different areas in the world.

Troops going to the war and refugees fleeing the war brought the disease with them. The people affected had no immunity against the disease, so their bodies were not able to fight it.

How immunity works

When your body is attacked by a virus, it responds by using a network of cells, tissue and organs to kill and clear the virus. Each kind of virus has something
a bit like a lock on it; only by opening that lock can your body kill the virus.

If this is the first time your body has ever seen that particular kind of virus, it needs to find the right keys to unlock it. This takes a bit of time, but once your body has learned what the key looks like, it will be able to fight the virus faster the next time it sees it. This is called immunity.

Vaccines give your body a sneak peek at the virus so it can make the keys and unlock, invade and kill it.

Edited by Charlotte Ames-Ettridge