What is a coronavirus and what is COVID-19?

Coronaviruses are types of viruses common in animals but capable of spreading to humans and causing disease.

Several coronaviruses are known to cause respiratory infections ranging from the common cold (an estimated 30-40% of common colds are caused by coronaviruses) to more severe diseases like Severe Acute Respiratory Syndrome (SARS). 

COVID-19 is the disease that stems from the most recently discovered coronavirus, SARS-CoV-2.

How is COVID-19 different from the flu?

Both COVID-19 and the flu are contagious diseases caused by viruses, and both cause respiratory illness. The symptoms are largely similar between the two diseases – fever, tiredness, dry cough and in some cases, aching muscles and joints, a stuffy or runny nose and a sore throat – however sneezing is not a major feature of COVID-19, just flu.

Early Symptoms of COVID-19

  • Fever
  • Tiredness
  • Dry cough
  • Aching muscles and joints
  • Stuffy or runny nose
  • Sore throat
  • Diarrhoea (less common)

Advanced Symptoms of COVID-19

  • Difficulty breathing
  • Extreme tiredness
  • Respiratory failure and/or organ failure

The symptoms of COVID-19 usually appear gradually, and in most people are mild or, in many cases, not even noticeable. The onset of flu, however, is much faster. This is one of the biggest problems with COVID-19 – it may take people longer to realise they are ill, so they risk spreading the virus before taking the decision to stay at home.

The risk of serious lower respiratory tract infection, pneumonia in particularly, is high with COVID-19. While 1% of people might be hospitalised with lower respiratory tract infections from flu, as many as 5-20% of people are likely to need hospitalising with COVID-19.

What is it like to have COVID-19?

Most people will experience mild flu symptoms such as aching joints or a dry cough. Others may experience fever and other symptoms listed above, but will not need hospitalisation.

5-20% of people will experience more serious symptoms, the most common of which is pneumonia, where the smallest part of the lungs becomes inflamed and fills with water, requiring systemic corticosteroids to reduce inflammation and clear the liquid.

Less than 10% of people will need assisted ventilation as a result of COVID-19, ensuring that enough oxygen reaches the rest of the body and avoiding the risk of heart failure.

Less than 3% of people will need to be placed on a ventilator as a result of COVID-19, ensuring that their lungs work full stop.

Unlike the flu, COVID-19 can infect other major organs such as the intestines and liver. A significant number of deaths from COVID-19 have officially been due to liver failure, likely caused by the virus.

How is COVID-19 spread?

The virus enters the body via the mouth, nose or eyes. It does so after you touch an object or surface with the virus on it, and then accidentally touch your face before washing your hands. It can also enter the body if you are exposed to someone with the virus coughing, sneezing or shaking your hand. According to the World Health Organisation, for most people, it is better to be properly and regularly washing your hands than wearing a face mask (which are often disposable and not meant to last longer than a few hours or a day in the first place).

Should I wear a face mask?

While studies have shown that there are benefits to wearing one when caring for an infected person, there is little (if any) benefit to wearing one in any other circumstances. The most effective way of reducing your risk of contracting COVID-19 is to regularly and thoroughly wash your hands.

Wearing a face mask is recommended if you yourself are infected, to help prevent spreading the virus to others.

Should I stay at home?

The largest spread of the virus has come from large gatherings such as churches and banquets, or enclosed environments like elderly care homes. This could apply to offices too, so it is advisable to work remotely if your employer will allow it.

The biggest concern for the continued spreading of the virus is from socially irresponsible behaviour like attending meetings or social gatherings despite having a fever or showing any other symptoms of COVID-19. An estimated 3,500 infections in South Korea are linked to attendance at a church where one woman in attendance refused to be tested or quarantined despite obvious symptoms.

The World Health Organisation state that most COVID-19 transmission has occurred indoors, even between family members or at social gatherings. This type of transmission is easy to minimise, but requires awareness of the symptoms in those who should isolate themselves, as well as awareness of how the virus is transmitted.

Who gets ill from COVID-19?

Unlike the common cold and flu, children and infants do not appear to be at much risk, with very few reported cases of infection and only one death to date globally in children or teenagers.

In Korea and Italy most infections were transmitted by small numbers of people to large groups.  In South Korea the most significant number of cases was within church groups, most of whom were over 60 years old.  In Italy most of the infected were older, over 60.

In China it appears that most transmission was within families, a problem that was likely made worse by the coincidental timing with Chinese New Year, a time when most people return home and spend time visiting various relatives.

Who is at risk of contracting COVID-19?

Anyone can be at risk, and everyone should take precautions in line with the current recommendations of local health authorities.

Age

The largest number of deaths so far has been in the Hubei province of China, but we will look to statistics from South Korea as of March 10th, as these are likely to be more reliable. Based on 7,513 cases and 54 fatalities, the risk of death from COVID-19 breaks down as follows:

30 and under 0%
30-39 0.1%
40-49 0.1%
50-59 0.4%
60-69 1.4%
70-79 4.2%
80 and over 6.8%

These percentages are lower those reported in China, possibly due to the advanced warning countries outside of China have had – enabling faster diagnoses. Further, many countries outside of China have reliable access to healthcare, which undoubtedly has an impact. The distribution of risk between ages will remain roughly the same in any country, however – so people over the age of 50 are at greater risk of developing severe symptoms or death with COVID-19.

The average age of death in Italy is 81.4 so far, compared to a current life expectancy of 82. The closeness of these two figures suggests that, on average, the virus kills people who are already at risk of death.

Pre-Existing Health Conditions

Based on statistics from China, people with pre-existing health conditions, especially chronic metabolic diseases, are at a greater risk when contracting COVID-19 – an overall death rate of 0.9%, which breaks down as follows:

Cardiovascular disease 10.5%
Diabetes 7.3%
Chronic respiratory disease 6.3%
Hypertension 6%
Cancer 5.6%

Apart from cancer, all of the above conditions usually involve systemic inflammation, making patients more susceptible to inflammation in the alveoli of the lungs. Chronic inflammation is uncommon in younger adults and children, which might explain why they are at less risk of death from COVID-19.

Combining the risk from both age and pre-existing health conditions that if you are young and healthy, your risk of death is very low. You can still get ill, and you can certainly pass the virus on to those at more risk, so precautions still need to be taken.

However these age-based statistics do not mean that you can’t catch the virus if you are younger, and everyone should follow hygiene recommendations.  It is also possible that populations with a lower life expectancy will see the average age fall, especially in countries with a large number of ‘at-risk’ people such as the US where metabolic disease and congestive heart failure/cardiovascular disease are endemic.

Smoking

Data has not yet been released on the effect of smoking on risk of death from COVID-19. That said, we know from studies on tuberculosis and flu that infection rates for respiratory diseases can be as much as four times higher in smokers than non-smokers, and the duration of illness is significantly longer.

The popularity of smoking in China – where almost 50% of men smoke regularly – may explain the huge difference in death rate between men and women.

It goes without saying that smoking damages and weakens the general health of the lungs. More specifically, it deadens the action of protective cilia through the lungs, meaning that the mucus we typically rely on to trap viruses and bacteria, is not removed in an efficient manner. Instead, mucus remains in the lungs and fails to trap any invading organisms looking to cause harm in the body.

Should you be worried?

We have to allow at least a small chance that this new virus is going to eventually become part of the background of infections diseases that we live with globally.  Most governments are taking sensible measures to slow the spread of this virus, however, which will mitigate the pressure on the world’s infrastructure – buying us more time for a vaccine to be created.

According to Tom Frieden of the Centers for Disease Control and Prevention in the US, the current mortality rate is “certainly an overestimate” because the majority of the statistics we are using are gathered from China and Italy where testing relative to the affected population has been minimal. The actual mortality rate is likely to be significantly lower than that currently estimated globally. South Korea has a mortality rate of 0.6%, and even this is likely to be an overestimate because there will be many people with less pronounced symptoms that never sought to be tested.

When the rate of spread is controlled effectively by quarantining patients and potentially exposed people, as seen in Singapore, the death rate can remain at zero – which it has in the country as of March 12th. If the initial spread in China occurred over months instead of weeks, the death rate could have been much lower due to less immediate and concentrated demand for hospital beds and ventilators, as well as more time overall to prepare.

Most measures currently put in place by governments are to prevent mass infections and to slow the spread of the virus.  This includes restricting travel from seriously affected areas, encouraging working from home and postponing large events such as conferences.

The US government has recommended that Americans most at risk of developing a serious illness from the new coronavirus – the elderly and those with underlying conditions – stock up on essentials (including essential medication) so that they can remain at home and avoid unnecessary exposure. This does not extend to stockpiling toilet roll.

Finally, a recent study from China suggests that peak transmission occurs at 8-9°C, meaning that spread of the virus is likely to slow down as Spring hits.

In other words, there is no need to be worried. All you need to do to put yourself in a good position is to regularly and thoroughly wash your hands, then take the extra precautions laid out below, and in information from your local health authorities.

How can I minimise my risk of contracting COVID-19?

There are several things we can do as individuals to protect ourselves, and as a community to protect everyone.  Governments globally have started restricting large gatherings, encourage working from home and reducing unnecessary travel.  Below are lists of what you should be doing to help prevent the rapid spread of this virus.

Individually

  • Wash your hands properly and regularly
  • Keep your immune system strong by exercising, sleeping properly, not getting drunk and avoiding excessive stress
  • Avoid large gatherings
  • Work from home if possible
  • Change social habits to avoid unnecessary contact such as greeting by cheek-kissing or shaking hands
  • Reduce the amount you smoke, or consider nicotine patches
  • Eat healthily – now would be a good time to start eating vegetables!
  • Support your immune system with glutamine, zinc and B-vitamins

Collectively

  • Slow down the spread of the virus
  • Encourage people to isolate themselves at home if they are ill
  • Avoid parties or social events if you suspect you may have the virus
  • Keep homes and offices warm and ventilated
  • Wear a face mask if you are infected, or if you suspect you may be infected
  • Cover your mouth and nose with a tissue, your elbow or your t-shirt when sneezing or coughing unexpectedly
  • If you have relatives or friends that fall in an at-risk group, make sure they know what to do to minimise their risk of exposure and infection