So I guess I'm writing about Coronavirus...

NB: This article was written on 7th March 2020 when the number of cases and confirmed deaths was lower than it is today.  I have chosen to leave the article unedited however, so you can read it in its original form.  The only significant change is that it is now believed wearing masks offers some reasonable protection.

Panic Pandemic
    I've been holding back on writing a Coronavirus article for three main reasons.  First, I don't want to get sucked into the circus because there's already enough people writing about it and it would seem gimmicky to join in.  Second, solid information on Coronavirus is pretty sparse, so I figured there wouldn't be much to say beyond speculation.  Third, I don't think I'm actually very good at writing about serious stuff - I'm much better at making Batman jokes than tackling something as unpleasant as a virus that kills people. 
    However, it occurred to me that a disease outbreak is one of those times when everybody actually wants to get engaged with science and seeing as how both my jobs (teacher and author) revolve around teaching science, it would be pretty dumb to stay silent at a time like this.  It's also just about reaching the point where reliable information is beginning to crystalise so, in the name of cheerful weekend blogging, here's my two cents on Coronavirus.

Not the time to be doing this...

Don't Tell Me What it Is...Tell Me How To Survive!
    Most articles and blogs start by explaining what the virus is.  My hunch is that most people aren't reading because they want to learn about virology however, it's because they want to know whether they and their loved ones are at risk, which is totally understandable.  If an asteroid was heading for Earth people wouldn't care about its orbital mechanics...they'd just want to know if we've contacted Bruce Willis yet.  So I'll give a cursory summary of the biology, but feel free to skip this section if you want.
    A virus is a semi-living box of chemicals that can damage the cells of an organism it infects.  Because viruses aren't exactly living things, you can't "kill" them with antiobiotics so your main defence is to rely on your rather amazing immune system.  Antiviral medications do exist for certain viruses but there aren't any blanket "kills 99% of viruses" medicines out there - viruses don't work the same way bacteria do. 
    Obviously you can and should give your white blood cells a thorough practice run against a virus by getting yourself vaccinated, but typically if you contract a virus you have to just wait it out and let your body go to work.
    Coronaviruses are a group of viruses we've known about since the 1960s and while most of them aren't harmful, there are a few versions which are.  Some Coronaviruses, like NL63 and HKU1 cause common colds, but some strains are way more problematic.  The two most dangerous are SARS and the one that's all over the news right now, SARS-Cov2 (Severe Acute Respiratory Syndrome Coronavirus 2) which causes the illness COVID-19 (Corona Virus Disease 2019). 
    We don't know where the original particle of SARS-Cov2 came from, and we probably never will, but analysing its DNA has shown that it's 90% similar to a version previously confined to the bat population.  This means there's a good chance SARS-Cov2 started out as a bat virus but then infected another animal which wound up in the Huanan Seafood Market in Wuhan, China, around December 2019. 
    Oh and if you're curious, it gets its name from the fact that under a microscope the virus particles look like they have little crowns around them and the Latin for crown is corona (you know how much scientists love translating words into Latin).  For the rest of the blog, I'll use the word "Coronavirus" to refer specifically to the one that's currently causing all the problems.   

What Does it Do To You?
    Coronavirus particles mostly cause damage to the cells in your respiratory system and when your immune system fights back the internal battle is what generates the most common symptoms...

1) Fever (your immune system produces a bunch of chemicals called pyrogens which tell the brain to increase cell production - like making more virus fighting soldiers - which causes things to heat up)

2) Cough (obviously...it's a virus in your lungs)

3) Tiredness and fatigue (your immune system uses up your body's energy to destroy the infection so you don't have much left over for other stuff)

4) A bunch of phlegm (a byproduct of your immune system breaking down the virus - like an icky slurry of dead white blood cells and burst virus particles)

5) Shortness of breath (obviously...it's a virus in your lungs)

6) Sore throat (obviously...your throat is attached to your lungs)

    As you can see from this list, the symptoms of a Coronavirus infection are very similar to other viral infections because your body only has a limited number of ways to tell you something is wrong.  In its most rare and severe cases however, Coronavirus can cause major damage to your lungs and the Greek for "lung disease" is pneumonia (scientists love Greek names too).
    It's potentially confusing that we don't just call pneumonia "bad lung problem" because I've heard a bunch of people getting muddled and thinking it's a separate virus, but pneumonia is just the name of the symptom.  About 4 million people die every year from bacterial or viral pneumonia and Coronavirus is the latest thing which can cause it.

This is actually what a cough looks like

How Dangerous Is It?
    This is a complicated question to answer because biology isn't a straightforward cause=effect science.  There are no absolutes in medicine and what works for one body will not necessarily work for another.  Biology works statistically and, unfortunately, statistics is something we're usually quite bad at as a species.  The human brain is built for straightforward calculations so when you get something that requires probability, risk-benefit analysis, overlapping categories and middle-of-the-road conclusions we tend to fall short.
    So far the response to Coronavirus has either been to get into hysterics and panic buy food from supermarkets or to dismiss it as "a bunch of hype that'll blow over in a few weeks like Swine flue, Bird flu, Ebola and Zika".  The reality is that Coronavirus is actually somewhere in between these two extremes and the danger depends on a lot of factors.  Getting worked up and spraying your armchair with bleach is probably going too far, but ignoring the whole thing isn't helpful either.  Like I said, it's one of those awkward medium-ground things that depends on context.

Right, But Seriously...How Dangerous Is It? 
    When you're talking about the danger of an infectious disease there are two main things you need to take into account.  One is called the R0 value (pronounced R- naught) and one is the mortality rate.

R0
    R0 is a measure of how easily an infection spreads i.e. how contagious it is.  There are lots of things which go into calculating it, such as how long the virus stays in the body before symptoms show, how long an infection lasts, how easily it can be transferred etc. but roughly speaking the higher the R0 number, the more contagious. 

An R0 value of less than 1 means it's quite hard to contract the disease.

An R0 value of exactly 1 means every infected person will infect 1 other.

An R0 value greater than 1 means each infected person infects several others. 

    When the R0 value is greater than 1 it means each person who catches it will infect several others, leading to what's called an epidemic or an outbreak.  The number of cases will grow at a faster and faster rate but it's important to note that R0 is geographically dependent.  For instance, the R0 value in Antarctica is going to be a lot lower than it would in Manila (the densest city in the world) because there are less people to infect.  As a result, R0 values are usually given as a range.  The more densely populated your surroundings, the closer you'll be to the higher figure.  Here are some common R0 values for comparison.

Measles                12 - 18
Chickenpox          10 - 12
Polio                      5 - 7
HIV                        2 - 5
Seasonal Flu         2 - 3
Ebola                     1.5 - 2.5
Swine Flu              1.46 - 1.48

    Coronavirus has an R0 of 1.4 - 3.8 so if you're living in a really densely populated place like the Hubei province of China, Coronavirus will spread faster than the flu, but if you're living in the Scottish highlands it's probably going to spread slower than Swine flu.
    If it gets to the point where the outbreak is found in the majority of countries across the world, the World Health Organisation will declare it a "pandemic".  That doesn't mean the majority of people have got it, it just means the majority of countries have at least one confirmed case. 
    At the moment it's hard to predict whether Coronavirus will become a pandemic but I'm going to be straight - it does seem a distinct possibility.  One of the problems is that because the symptoms aren't too dissimilar to a lot of other diseases a lot of people contract it and don't even realise, shrugging it off as "a cough".  That makes it difficult to catch because if we quarantined everyone who had a cough we'd be quarantining tens of millions of people. 
    With the SARS outbreak of 2003 we were able to contain the infection because the symptoms and the transmission went hand in hand, but Coronavirus is sneaky and people can be carrying it around without showing any signs. 
    I'm not wanting to be all doom-and-gloom and it's obviously possible that we've identified it early enough to stop further spread...but I want to be realistic.  There is a very real chance Coronavirus is going to keep spreading and we might end up with a pandemic.

Mortality Rate
    This is the really grim bit.  Of the people who get Coronavirus, how many end up with a pneumonia so serious it shuts down their ability to breathe?  The answer, again, depends on who you are and where you live.  If we take something like seasonal flu for instance, that has a mortality rate of 0.1% in the US.  In Nigeria however it's the number one cause of death.  Likewise, something like Ebola has a mortality rate of 90% but it largely affects areas with poor healthcare and widespread poverty.
    The World Health Organisation official number for Coronavirus right now is 3.4% but that statistic can be misrepresented to the point of not being useful.  The mortality rate in China is currently 3.8% but that's a country with a dense population and the highest rate of smoking in the world (around 28% of the population). 
    By contrast, the mortality rate in the UK is, at the time of writing, 2.4%.  That raw percentage makes the death rate in Britain seem almost as bad as that of China.  But in fact only two people in the UK have died from Coronavirus, one of whom had an underlying illness and one of whom was 88.  Giving a percentage when there's such a small number of cases is probably not the best way of expressing the data.
    The really interesting statistic to my mind is that of South Korea where there are over 6,500 confirmed cases, but a 0.6% mortality rate.  The explanation is currently not known.  It could be that South Korea is doing something differently or it could be a statistical blip.  Some countries are, by pure chance, going to have less deaths than others.  We don't know at the moment. 
    There's also the fact that the WHO 3.4% number is based on the number of reported cases.  But because a lot of people get Coronavirus and don't even realise, they never report it so the actual number of cases could be much higher, meaning the mortality rate would be a lot less. 
    The mortality rate of Coronavirus could in truth be lower than 3.4% but that's still not brilliant.  The last time we saw something like this it was Spanish flu in 1918 which had an R0 value of 2-3 and a mortality rate of 3% (very comparable) but because we didn't contain the spread effectively, a third of the world's population contracted it and about 30 million people died.  So although those numbers might seem quite low, if we ignore Coronavirus and don't take it seriously, we could be facing a major problem.

You're Fine But Your Neighbour Might Not Be
   As I said earlier, my gut feeling is that when people read about Coronavirus they either want to be reassured that they and their families are safe or they want to be warned if they are in danger and told what precautions to take.  The tricky bit is therefore how we package the answer when people ask if they're at risk. 
    If we tell people the short answer: "the vast majority of people who get Coronavirus are going to be absolutely fine" then that is completely accurate but it means they will mentally file Coronavirus under the nothing to worry about category in their brain.  That's understandable because that's how our brains work - if something is not an immediate threat, our brain relaxes and stops taking it seriously.  But we need to be more sophisticated about how we approach Coronavirus.  Here's why...
    We currently don't have a vaccine for Coronavirus and developing one could take up to a year or longer.  That means between now and then if you contract it, you're basically on your own.  Most people have functioning immune systems so their body will take care of it just fine, but people who don't have good immune systems are at risk.  The WHO 3.4% mortality rate is an average of young and old people but if you're 70-79 the mortality rate jumps to 8% and if you're 80 or over it jumps to 15%.  That's significantly worse than seasonal flu.
    Most of the people asking me abut Coronavirus are teenagers and the answer for them is that they're in the lowest risk category (0.2% mortality rate).  So for most of my readers you don't need to be alarmed even if it does get to pandemic stage.  If you contract it you'll most likely have a cough for a few days but then your body will work its magic and you'll feel fine again.  But you could carry the infection and transfer it to your grandparents and then it could be a lot more serious.
    It's rarely a good idea to express a complicated idea in a simple soundbite of a few sentences but on the other hand, people remember succinct answers better than essays.  So, for what it's worth, from a scientist's perspective this is roughly the deal with Coronavirus...

    As a general rule, healthy and young people are not at serious risk, so you probably don't need to live in constant fear, HOWEVER people with immune problems and the elderly are at risk so we need to take precautions for their sake. 

    I know that's not a simple answer, but I'm afraid Science is sometimes not simple.  It does mean that when you hear all the scary stuff on the news, you personally don't need to be fretting too much.  But turning a blind eye and shrugging the whole thing off is not the way to go either.  It's better to err on the side of caution when it comes to something like this because even if you aren't at risk yourself, other people around you could be.

Seriously

Quick and Important Coronavirus Facts...

How Is It Transmitted: We think it's mostly transmitted via what are called "respiratory droplets" which basically means moisture from your lungs.  Coughing, sneezing etc. the same as most respiratory infections.

How to Keep Safe: The same thing you would do in regard to any viral outbreak.  Don't be around people who are coughing and sneezing all over the place, wash your hands with 60-95% alcohol based hand sanitiser or if this isn't an option for you (religious reasons might prevent you for instance) wash your hands regularly with warm water and soap for about 20 seconds minimum - that's the time it takes to sing Happy Birthday twice.  Also, if you see people coughing and sneezing openly rather than into a tissue they dispose of etc....politely call them out on it.  We're all in this together and we really can slow it down.

Face Masks: Wearing a face mask doesn't do much to protect you I'm afraid.  However if you've got Coronavirus, wearing one will help stop you spreading it to other people.  This sounds a bit of a contradiction but it's because if you're coughing and sneezing, the mask will keep most of those droplets inside, but if it's already out in the air, the mask won't protect you from breathing it in.  They also do have the slight advantage of stopping you from touching your own mouth.  There are specially designed respirators called N95s which can protect you, but right now they are being given to healthcare professionals on Coronavirus wards...which seems pretty fair.

Can Children Get It?: Yes, as far as we can tell they are just as likely to catch the virus as anyone else.  They don't seem to be at risk of symptoms however and there aren't any deaths reported for under tens anywhere in the world, but they can carry the disease and spread it.

What About Pets? This one is unclear.  There are a few stories of people's dogs getting it in China but I'm afraid it's hard to know how transmissible it is.

I heard it was designed artificially in a lab by the government as a secret population control device: This isn't the website you're looking for.

Natural News might be more your thing...

The Future
    In all likelihood, things are going to get worse before they get better.  That's the way viral outbreaks always happen though.  Because Coronavirus has a high-ish R0 value and in many people the symptoms are too mild for them to realise they need to self-isolate etc. it will spread fast. 
    So what happens next?  Well, there are a few possible outcomes and it all depends on how we and our governments respond to the threat.   The worst case scenario is that if we get to the point where 50% of the population contract it, half the world will all develop a natural immunity.  Once that happens, the virus will slow down because there will be less people to infect and the R0 will drop.  If the virus goes unchecked and we never develop a treatment this is what will ultimately happen.  We'll develop a herd immunity and the virus will become endemic - but not after several million people die. 
    Slightly more optimistic is that the virus will mutate to the point of becoming less dangerous.  This sounds counterintuitive but viruses are sort of self-defeating sometimes.  If they're super virulent (I know it seems like I'm making a pun there, but the adjective happens to stem from the thing I'm talking about) then they can kill the host, but if they kill the host the virus can't keep spreading.  That means ironically, the more deadly a virus is, usually the quicker it kills itself off.
    If we're extremely lucky, it's possible that when the summer rolls around the virus will slow down.  You might have heard Donald Trump saying the Coronavirus would die off when the weather got warmer and actually, he's not wrong - that really could happen.  Some viruses  don't transmit as well in warmer, dryer conditions and become seasonal, like the flu.  However, there currently isn't any indication of whether Coronavirus will do that or not.  It could just as easily keep going through the summer right on through.  But if it does slow down, that will buy us time to develop a much-needed vaccine or anti-viral medication.
  
Ultimately, Science Will Win
    One thing keeps coming up again and again when you read about Coronavirus, which is a comparison to other pandemics of the past.  And the important thing is that we keep winning.  You don't hear much from polio these days, or leprosy, or bubonic plague.  But all those diseases still exist.  It's just that we've become so darn good at science-ing that they don't get a foothold any more.  The last time we faced a pandemic that could kill people like this it was Spanish flu, and that was a hundred years ago.  This time we're armed with knowledge of DNA, techniques like CRISPR and the blessed internet to share information across the globe. 
    Every day, Science is in a stronger position than it was the day before because knowledge only increases.  It's like entropy - the value can go up, never down.  We have literally never been in a better position to handle and combat a viral outbreak.  Every new case adds data to our understanding and there are legions of Biologists accross the planet working round the clock to develop a vaccine or a medicine that will stamp it out. 
    Yes, it presents a problem and yes there could be rough times ahead and, yes, there will be more deaths.  But Coronavirus will not bring about the apocalypse.

The three books I've written all finish with the same sentence.  It's also the sentence I have on my homepage. I feel like it's important to remember now more than ever something very important:

Science will save our species


Image Credits
Infection map: BBC
Head in sand: Virgin
Coronavirus: Wikipedia
Cough: Sciencealert
Obi Wan: Star Wars