[Last Update : 15th of March, 2020]
During the last one week, I did some reading about COVID-19 and its spread around the world. I am trying to share my learning from that. The sources are mentioned at the end of the post.
Myth : Karnataka, India has just 6 cases and hence the virus is contained
This is the most important graph about the spread in Hubei Province, China which we should understand (Source)
Orange bars – number of patients diagnosed and officially confirmed on a particular day. Grey bars – number of people who started showing symptoms, but not yet diagnosed.
For example, on Jan 21st there were 100 confirmed cases, but 1500 people started showing symptoms of infection on that day. These 1500 cases were confirmed at a later point of time. This statistics has been proven to be true for France and Spain as well.
Similarly on 15th March, Karnataka has just 6 confirmed cases and seems to be safer and contained, but number of true cases may be much higher. Only time will tell how many people are infected at this point of time.
Myth : No one is coughing around me and I am safe
Around 80% infections show mild or no symptoms (Source). Microbiologist Yuen Kwok-yung from Hong Kong says that if there are 100 patients showing symptoms, there could 800 patients without showing symptoms. These 800 will never be confirmed because they may never be tested. Many patients heal on their own, but they transfer the infection to their elderly or low immunity contact, causing them to die.
Kids tend to have very mild infections (probably minor cough & not even runny nose), but they may pass the virus to the domestic help, parents or grandparents. That is the reason the Government has shut down the schools as the initial step.
Myth : I am below 50 and I am safe
The mortality rate for COVID-19 is around 3% to 4%. The mortality rate is much higher for older people, hence they should take all the precautions possible.
However, if you are below 50 with certain health conditions (cardiovascular disease, diabetes, lung conditions, chronic respiratory disease (smoking), high blood pressure, and cancer), you are also vulnerable (Source).
Myth : I am in my 20s and I am safe
Italy is testing people who are showing symptoms. South Korea is testing even without symptoms. The age group 20 to 29 are highly infected, but they probably feel fine. Apart from the fact that they are spreading the infection, no one right now knows the after effect of COVID-19. So, please be careful. Source
Myth : All my coworkers are healthy and none of them have recently traveled abroad
At this point of time, most of the infections in India have a travel history. But these infected people are spreading the infection to others whom they are in contact locally.
Myth : India has just 100 cases but Italy has 17K with such a small population
Absolute number does not matter. What matters is how fast the infection is spreading (For example we care about rate of returns for any investment and not the absolute value of the return). In China, right now, the number of infections are doubling every 33 days. In India it’s doubling every 6 days. Italy is doubling every 5 days. You can keep an eye on this rate here and then decide on the severity. In South Korea, 31st patient passed the infection to thousands (She had 1160 contacts) (Source).
Myth : It’s a virus and any way it will infect everyone. Why Social Distancing?
Correct. This is Virus and at some point of time it will infect probably most of humanity unless there is a vaccination invented (which is at least 12 to 18 months away). But, by social distancing we can slow down the spread of the virus, so that our healthcare system can take care of all the infected people at any point of time. If the infection becomes wild, the healthcare system will crash. Doctors and Medical Stuffs will also be tired and infected resulting in a situation where even if you have non-Covid disease (say Gallbladder Stone) you will not get treatment.
We need to do everything as a country to remain under the dotted white line (representing health care system capacity) in the following figure (Source).
Myth : In India, temperature is higher. Hence problem will be contained.
Probably. Microbiologist Yuen Kwok-yung from Hong Kong says “I believe the temperature will have certain impact on the toxicity of the virus because, for example, when we do animal experiments on influenza virus, its toxicity in animals placed in 15 degrees Celsius (59 degree Fahrenheit) will be 10 times higher than in those in 25 degrees Celsius.” Maybe that’s why there are so far only 2 deaths (as of 14th March). However, humanity doesn’t have sufficient evidence to prove this point. Only time will tell, if we are simply lucky because of our geography or not.
Question : I want to know the true numbers, not the reported numbers. How many people are really infected in India or in my native state?
Tomas Pueyo author of the blog “Coronavirus: Why You Must Act Now” has released two models (Link). Using those you can try to figure out the true numbers. Please note the authenticity is of the model has not yet been proved.
“You only know the official cases, not the true ones. But you need to know the true ones. How can you estimate the true ones? It turns out, there’s a couple of ways. And I have a model for both, so you can play with the numbers too (direct link to copy of the model).” —Tomas Pueyo
Khanacademy has also published a video about how to use the model.
Fact : Social Distancing is the only way to contain COVID-19
Government of Karnataka has understood the gravity of the situation and forced Schools, Malls, Cinema Halls etc. to be closed. IT Companies have been advised to allow their employees to work from home.
The 1918 Flu Pandemic, infected 500 million people around the world and resulted in the deaths of 50 to 100 million. The above graph (source) shows how many more deaths were there (across different cities) depending on how fast measures (including social isolation) were taken. Taking measures 20 days earlier halved the death rate.
City of Denver took measures and then withdrew it resulting in a higher number of deaths during the second peak.
The idea is using social distancing we need to reduce the spread of the virus. And it MUST be there as long as needed.
Jeremy Howard‘s (Founding researcher at fast.ai) blog on COVID-19 inspired me to explore further about this topic.
- Coronavirus: Why You Must Act Now
- Covid-19, your community, and you — a data science perspective
- Q&A with HK microbiologist Yuen Kwok-yung who helped confirm coronavirus’ human spread
- Coronavirus in brief (sharing)
- Characteristics of and Important Lessons From the Coronavirus Disease 2019 (COVID-19) Outbreak in China
- The Epidemiological Characteristics of an Outbreak of 2019
- Coronavirus Disease (COVID-19) – Research and Statistics
- Public health interventions and epidemic intensity during the 1918 influenza pandemic
- What Worked in 1918-1919?
- The Korean clusters
- Coronavirus: Why it’s so deadly in Italy