A pandemic explained. Causes and results. Easy science. Understanding the coronavirus pandemic better.

A pandemic is a horrifying term.
We're conditioned through movies books and history to know it means disease, death and mass panic. I mean the word pandemic literally has the word 'panic' in it. But what exactly is one? How was it declared? And what happens if there is a pandemic?

In order for a pandemic to occur, it needs to start with an outbreak. If we look at the disease Covid-19 the outbreak occurred in Wuhan, China from the SARS CoV 2 virus.

A viral outbreak requires a new virus that humans do not have immunity to, that is able to infect humans, cause disease in humans and spread from human to human quite easily. If the disease spreads within an initial community or within a specific region or country it's known as an epidemic.

Surprisingly, for something to move from being an epidemic to a pandemic, it has nothing to do with the severity of the disease, but rather its geographic spread.

The exact definition varies within organization to organization, but in general, if a virus begins to spread across international borders and around the world, only then is it considered a pandemic.

But it actually isn't that simple. If you contracted Covid-19 in China but then went home to America and spread it to someone there, that doesn't count as crossing international borders. It becomes a pandemic when people start to get infected by people who have no traces to the infected countries or the initial epidemic center. An example of this is community spread when someone gets a disease, but the source of the infection is unknown.

It might help for us to look at some historical pandemics. Some of these pandemics actually happened thousands of years ago. For example the Antonine plague, which happened to the Roman Empire when troops returned home from the east. It's estimated that this pandemic killed five million people across Greece, Italy, Egypt, and modern-day Turkey. We don't exactly know what caused the pandemic, but researchers think that it was smallpox.

Then, of course, you have perhaps the most famous pandemic: the Spanish flu in 1918, which isn't actually named so because it started in Spain. It's believed that it may have originated in an army camp in Kansas, which was then brought over to Europe by troops. But it's named the Spanish flu because Spain, a neutral country during World War I, openly reported on its occurrence while other countries censored or tried to hide it. This time 500 million people were infected and an estimated 50 to 100 million died, which was more people than World War I killed.

What was perhaps the scariest part was that it actually had a second wave in October, so the first wave affected people who were primarily elderly or really young or sick, but the second wave actually affected people between the ages of 20 to 40 severely.

Interestingly, the war is often considered a contributing factor. Not only because troops were moving around the world with improved transportation and technology, but soldiers were actually more prone to getting the flu because of stress, malnourishment and chemical attacks. But just as fast as the Spanish flu hit its worst point, it quickly died out.

After the peak of the second wave in October, places went from having thousands of deaths to none. One theory suggests that the virus actually mutated away from its most lethal strains as people died out with those lethal strains. All that was left over was more mild versions.

But now in, our modern world, when does a pandemic get officially declared?

We look to agencies such as the Center for Disease Control and Prevention, the World Health Organization (WHO) or the European Centre for Prevention and Disease Control to declare a pandemic. But different scientists, epidemiologists or collectives could technically declare one based on their own judgments.

You may think this would be an easy decision. Once it acts like a pandemic, call it a pandemic, but these viruses are hard to trace, especially if the disease has a long incubation period or causes minor symptoms leaving diagnosis untraced.

There are other issues with claiming a pandemic as well. For example, the WHO came under a lot of scrutiny in 2009 when the H1N1 virus was declared a pandemic. This is because it led to some unnecessary panic and a lot of countries ended up spending money to develop a vaccine for the flu when it ended up being fairly mild and easy to contain.

Official classification of a pandemic by institutions depends on a variety of factors. But surprisingly, it's simply a label and actually has no legal implications. The WHO has declared Covid-19 a public health emergency of international concern, which in many ways is more important. It allows them to start making recommendations to member countries on how to handle the disease and also mobilize funding and political support.

But when a pandemic is declared, it does mean the disease has spread to many countries around the world and that's significant. We obsess over the word because it holds power. Declaring a pandemic could cause unnecessary panic, which has many downsides but, on the other hand, it could also allow the citizens of the world to mentally and physically prepare for the spread of the virus and disease, and this might actually help with mitigation.

There are pros and cons to the declaration of a pandemic, but that brings us to the next question is: What do you do when organizations start declaring a pandemic?

First off, you need to listen to healthcare professionals. They are on the front line of these situations and are prepared to work with epidemiologists, researchers, and scientists to effectively curb the disease.

Be wary of unverified exaggerations and disinformation online. Again, if one is declared, nothing will legally change, but naturally people will act accordingly. Hospitals around the world will become the front line of defense, putting the sickest first and postponing unnecessary surgeries and appointments. Hospitals will also be extremely busy, so households, businesses, and communities will also need to work independently to decrease spread. Social isolation will become more normal and mass gatherings will be canceled.

We'll all have to get used to washing our hands effectively and all the time and learn to not touch our face. The world will get better at normalizing not greeting each other with a handshake, a little elbow touch or just a little nod. How do you do?

There will be an emotional reaction as we prepare to potentially care for sick family members, which is actually a good mental exercise in order to keep our families safe and the hospitals less strained. Offices will need to make plans for when workers are sick or off to take care of their family members all while the world works together to make a vaccine and antiviral medication to help curb the disease.

Of course, there's no use in unnecessary panic, but declaring a pandemic is a useful way to have the world come together and work together in containing the disease or virus. So what should you be doing personally?

Make sure you're listening to legitimate organizations like the CDC, WHO, and ECDC for up-to-date information and recommendations. It's possible that advice will change from day to day and staying up-to-date with accurate sources is the most important.

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DISEASE= Illness.

OUTBREAK= A sudden occurrence. In epidemiology, we call an outbreak to the moment when an epidemic suddenly starts in a place.

COVID-19= Best known as: coronavirus.

SPREAD= When a virus or desease spreads, it infects more people and covers a wider area.

ONLY THEN IS IT...= If we start a sentence with "Only then", or "Not only", we need an inversion, like in a question (Not only can you do it, but you must do it / Open the cover. Only then will you see what's inside).

CONTRACTED= If you contract a virus or a disease, you get infected by it.

TRACES= Signs.

PLAGUE= A highly infectious epidemic disease, especially one killing many people.

SMALLPOX= A severe, highly infectious, often fatal disease, producing lots of pimples all over your body (especially your face) that blister, produce pus, and leave marks for the rest of your life. This disease was eradicated worldwide by 1979.

WAVE= In epidemiology, we talk about "wave" when lots of people are infected and then the disease disappears or greatly dicreases, especially if we have more than one wave.

PRONE TO= If we say that something is prone to happen, or people are prone to something, we mean that something will probably happen because of present factors will make it easy to happen.

MALNOURISHMENT= The situation of not having enough food or the quality food that your body needs.

DIED OUT= Disappeared.

PEAK= The peak of a wave or curve is the highest part, just when it reaches its maximum and starts to go decline or go down.

STRAINS= Virus usually mutated fast, so after some time we get some differences, like different families of viruses within the same kind. Those different groups are called "strains", so a virus usually generates different strains, each a bit different from the others, each more or less lethal and dangerous.

LETHAL= Causing death.

TRACE= To spot, to know where they are (or if they are there).

INCUBATION PERIOD= The time which passses from the moment a person gets infected to the moment that person starts feeling ill.

ISSUES= Problems.

SCRUTINY= If you come under a lot of scrutiny, you are carefully examined, investigated. In this case, even criticized.

H1N1= Better known as: Influenza A or Grippe A.

CONCERN= Worry.

HANDLE= Manage, cope with.

FUNDING= Money (for a certain purpose).

DOWNSIDES= Problems, objections.

FIRST OFF= First of all, to begin with.

CURB= Decrease, reduce, bring down.

BE WARY= Be careful, pay attention.

UNVERIFIED= Something which may be true or false, we don't know.

SURGERY= A hospital operation.

SOCIAL ISOLATION= The state of having no contact with other people.

STRAINED= Stressed, over busy.

VACCINE= A medical preparation, usually administered with an injection, which can make you immune to a certain virus.

ACCURATE= Exact, trustful.