Coronavirus isolation precautions are an extreme measure, but the situation calls for it. Our expert explains the risks from a medical perspective.
The new coronavirus outbreak, known to medical professionals and labs as COVID-19, is a landmark event that has the potential to change the world. This unplanned stress test of global population health and healthcare systems is putting immense strain on countries and inhabitants.
Uncontrolled, this virus may well cost millions of lives, but the risks don’t stop there. This new coronavirus could destabilise the economic and financial reality of the world’s population by halting trade, closing borders and increasing distrust between countries and people.
Highly contagious viruses are not exactly in our wheelhouse at Atlas Biomed - we specialise in microbiome and DNA testing - but we are fortunate to have strong connections to medical scientists in a number of fields.
Today, we are stepping out of our comfort zone to share evidence-based facts and hard science with Dr Hoda Kardooni, PhD, specialised in Genetics, on COVID-19 transmission, the new coronavirus statistics and incubation periods to combat the disinformation and shed light on government guidelines.
Table of contents
- Coronavirus deaths: how deadly is the virus?
- Coronavirus cases: how transmissible is the virus?
- Data in context: why coronavirus is a population risk
- How COVID-19 compares to other infectious diseases
- What can we do to slow the rate of transmission
- Lessons from history for COVID-19
- Coronavirus isolation and strategies
There are a few criteria that indicate how dangerous a virus is, some of the most important ones are:
- How deadly is the virus? (CFR)
- How transmissible is the virus? (R0)
- How long does it take to show symptoms (Incubation Period)?
In order to efficiently control the epidemic, we need a plan to reduce the rate of transmission (lower R0) and mitigate lethality to decrease the number of lost lives (lower CFR).
CFR (case fatality rate) is the number of patients who died from COVID-19 divided by the total number of cases who got infected. High CFRs tend to occur in places where access to proper healthcare is limited (especially for the most vulnerable) as well as insufficiencies in national healthcare systems (including limited monitoring and capacity to trigger a timely response).
CFR can be easily manipulated by the total number of infected cases. Consequently, it is crucial to get the total number as accurate as possible. Although, it is not easy to find the exact total of infected cases as many people only develop mild symptoms and stay undiagnosed.
COVID-19 has more fatalities in old and sick people, but it has also killed some individuals with no underlying health problems. This adds another layer of complexity to this virus because the specific mechanisms underpinning how the virus affects the body are still not understood.
R0 (reproduction number) is the average number of individuals estimated to be infected by a single infected person. In the case of COVID-19, every infected person will transmit the virus to 2–4 other non-infected individuals on average.
R0 is affected by the following factors:
- The number of days a person is infectious (COVID-19 is currently estimated at 4–14 days)
- The number of people susceptible to be in contact with the infected person (influenced by self-isolation)
- The likelihood of those non-infected people to catch it during that contact (influenced by hand hygiene, covering the sneezes and coughs, touching the face, etc.)
We are dealing with a virus that has a relatively long incubation period and course of illness. Also, it is quite contagious as we learned one person can infect 2–4 people with the CFR of about 0.25–3.00%.
When we consider all these facts together, we understand the severity of this situation and the importance of the essential steps that need to be taken by people and governments. COVID-19 is not another flu!
The reproduction number for the flu is 1.3 while this number for the new coronavirus is estimated from 2–4. The CFR rate for COVID-19 is about 3% which is 30 times larger than the flu (0.1%). Moreover, the incubation time for COVID-19 is 4–14 days in comparison to 1–4 days for the flu.
The new coronavirus is not the most deadly or transmissible of viruses, but it is high in both categories. In the diagram below you can see how COVID-19 compares to the other infectious diseases.
The new coronavirus has a relatively high mortality rate. However, it is less lethal compared to SARS and MERS. Yet, the new coronavirus seems to be more transmittable with much higher incubation time.
As a result, this virus is very difficult to deal with because infected people can pass it on to others during the incubation period: you can be infected by individuals who have no symptoms.
Consequently, young carriers with no or mild symptoms can bring the virus home to grandmas, grandpas, or their friends who have underlying health conditions (e.g. diabetes, heart disease, stroke, high blood pressure, asthma, COPD, cystic fibrosis, kidney disease). These people are at the highest risk of serious complications from COVID-19.
However, as we are in the midst of COVID-19 unfolding, there is still time to change these numbers favourably and put the cat back in the box!
R0 represents how fast the disease spreads but remember that our behaviour also affects the R0. So, for example, washing hands and avoiding large groups would reduce R0: these measures can slow down the epidemic.
Slowing it down can make a big difference, especially on the number of people who get the disease at the same time.
Although some epidemiologists estimate that eventually around 60% of us will contract COVID-19, it is absolutely essential that we do not get it all at once. The high number of simultaneously infected people will overwhelm hospitals and there will not be enough intensive care unit beds to accommodate every patient.
Do not forget that there are other patients who need the hospital beds too! Here, it's important to remember that COVID-19 is not the only health problem out there. Other people may require immediate care for serious complications of diseases and life-threatening accidents.
Do not forget that there are other patients who need the hospital beds too! Furthermore, we need enough doctors and nurses to take care of these patients. Hence, if we reduce the simultaneous infections as much as possible, our healthcare system will be able to handle the cases much better leading to a lower fatality rate. Besides, if we spread this over time, we may reach a point where the rest of society can be vaccinated.
There is one very simple thing that we can all do, and it really works: social distancing. The only way to truly delay the spread of the disease is by keeping people at home as much as possible, for as long as possible. People need to start social distancing to drop the transmission rate from the current value (2–4) to a manageable number (around 1), so that the impact of the virus eventually dies out.
For example, if we reduce the rate of spread from 3 to 1.2, every infected person can infect just one more person which is a huge success in controlling this virus. Furthermore, if we can reduce the mortality from 3% to 0.5%, it will have a profound effect. History also shows that isolation and social distancing is helpful.
How long the virus survives on different surfaces
COVID-19 can survive up to 3 days on different types of materials that you encounter in daily life:
- Copper: up to 4 hours.
- Cardboard: up to 24 hours.
- Plastic: 2–3 days
- Stainless steel: 2-3 days.
During the 1918 Spanish flu, countries that closed schools and cancelled social events significantly reduced the number of simultaneous cases and eventually had a lower total number of mortalities.
As you can see from this illustration, the time it took local cities in the US to intervene against the transmission of Spanish flu significantly impacted its course: there was a big, sudden spike in deaths in Philadelphia compared St Louis. Spikes like these are what public health measures aim to prevent.
We can see how this worked in South Korea just recently. They used this strategy, alongside with other measures, to flatten the curve, leading to a reduced number of people who got the virus at the same time.
This saved more lives (lower fatality rate of ~0.5% in comparison to the global rate of 3% to 5%) and helped the health system to maintain optimum performance.
Social distancing by working from home, closing schools or switching to online classes, calling loved ones instead of visiting them in person, cancelling or postponing conferences and large meetings. This virus can be spread within 2 meters (6 feet) if somebody coughs or sneezes.
Hygiene: clean and disinfect frequently touched objects and surfaces. The virus survives for up to 3 days on different surfaces such as metal, ceramics and plastics. That means things like doorknobs, tables, or elevator buttons count as significant infection vectors.
Handwashing more often with soap and water for at least 20 seconds, especially before eating. Avoid touching your eyes, nose, and mouth before washing your hands. Soap and water deactivate COVID-19 by breaking down the lipid membrane of the virus.
Care for others: avoid close contact with people who are already sick - they may be more susceptible to the new coronavirus. Stay at home when you are feeling unwell so you don’t expose others. Always cover your cough (but not with your hands) and sneeze into a tissue, then dispose of it immediately.
☝️Acknowledgment☝️ Special thanks to Reza for designing the graphics and illustrations.
- Wu, Z. and McGoogan, J., 2020. Characteristics of and Important Lessons From the Coronavirus Disease 2019 – COVID-19 – Outbreak in China. JAMA.
- Guan, W.,et al., 2020. Clinical Characteristics of Coronavirus Disease 2019 in China. New England Journal of Medicine.
- Ruan, Q., Yang, K., Wang, W. et al. 2020. Clinical predictors of mortality due to COVID-19 based on an analysis of data of 150 patients from Wuhan, China. Intensive Care Med.
- Zhonghua Liu Xing Bing Xue Za Zhi. 2020. The epidemiological characteristics of an outbreak of 2019 novel coronavirus diseases – COVID-19 – in China
- World Health Organisation, 2020, Report of the WHO-China Joint Mission On Coronavirus Disease 2019
- Center For Disease Control, Estimated Influenza Illnesses, Medical visits, Hospitalizations, and Deaths in the United States — 2018–2019 influenza season
- Center For Disease Control, 2020, Nonpharmaceutical Measures for Pandemic Influenza in Nonhealthcare Settings—Social Distancing Measures
- Center For Disease Control, When and How to Wash Your Hands
- Centre For Mathematical Modelling Of Infectious Diseases, 2020, The Contribution of Pre-symptomatic Transmission to the COVID-19 Outbreak
- The Guardian, 2014, Visualised: how Ebola compares to other infectious diseases
- Australian Government Department Of Health, Coronavirus (COVID-19) – Information on social distancing
- van Doremalen et al., 2020, Aerosol and Surface Stability of SARS-CoV-2 as Compared with SARS-CoV-1, New England Journal of Medicine