What is flu? The essential facts about the disease formally known as influenza
Winter is coming, which means flu season is here; make sure you know how to protect yourself from this illness which can range from being unpleasant to deadly
The northern hemisphere’s flu season is upon us, the time of year when, the temperature having dropped, cases of influenza virus infections peak.
There have been many famous influenza pandemics throughout history, such as the Spanish flu of 1918, which killed between 40 and 50 million people; the Asian flu outbreak which lasted two years from 1956 and killed about 2 million; and the Hong Kong flu of 1968-69 which led to approximately 1 million deaths worldwide.
But what exactly is the disease, is it always that serious, and should you be worried?
What is flu?
Different kinds of flu viruses affect different animals, including humans. There are three main forms that infect humans: Type A, Type B and Type C. The 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.
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.
How to protect against flu
Each year, the World Health Organisation (WHO) 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.
Young people’s immune systems should be able to cope with the flu. However, some governments recommend that everyone in reasonable health over the age of six months receive the vaccine. Since there are different strains, scientists work out the best vaccine to combat that year’s likely culprit, and give you the best possible protection.
How to prevent flu spreading
In many apartment buildings, office blocks and campuses, you may see cleaners going around regularly wiping lift buttons, door handles, and other surfaces likely to be touched by a lot of people.
But you need to do it properly: 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.
Why everyone gets freaked about flu
Like we said, flu kills. The huge numbers who died during the Spanish Flu pandemic were 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.
But more recent outbreaks have also affected huge numbers of people, such as the bird flu which made headlines in the early 2000s, or the swine flu epidemic of 2009, which prompted the WHO to issue its first ever declaration of Public Health Emergency of International Concern.
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.