Why Lock-down should work - Virus Bottleneck

In a situation like the Deuterium Bottleneck, if the availability of deuterium is too low then the necessary nuclear fusion does not happen. (See link below for BigBang Nucleosynthesis). This can be used as a comparison to the spread of a virus. (One can also use  as an example -The Plasmodium bottleneck: malaria parasite losses in the mosquito vector -Wiki)

Let's assume you live in a village with 1000 people. Take the average value of R0* as 2.2 (calculated from various WHO-sanctioned studies) and the number of infected people on Day 1 as just 1. Let's also assume that everyday 2.2 people will be infected for certain.If we calculate the total number of infected people on Day 2, it would amount to 1 + 2.2 = 3.2. This would result in the number of people infected per day increasing to 1005 by Day 09. Therefore, by this time, all 1000 people in your village are already infected. But incubation period is 2-14 and not everyone will show the symptoms.

Below graph will show if the original value multiply by 2, 4,8,32 etc and (lower blue) and if we add the previous days figure (orange)

Now, let's take a lower value of R0 = 1.5. Using this value, we can work out that all 1000 people will be infected by Day 18. 

If we apply the worldwide death rate (5.5%) to the village of 1000 people, 55 of them will have died from the virus. Its incubation period is 2-14 days. If we were to lock down the whole village on Day 5 and prevent any contact between people, the virus would reach its bottleneck. After initial infection, it will not be able to infect anyone again. Therefore, if we test everyone else and advise healthy people to stay away, the total number of deaths could shockingly be reduced to only 1 or 2.

However, these figures could vary for many reasons. For example, some people may hide their infected status or just not volunteer to be tested (as seen in some cases in Sri Lanka). In that case, the virus will keep spreading, but will be significantly mitigated by the lock-down.

However, virus will stop spreading once when movement of people restricted and when the most serious cases would not recover. Those who will recover will have the immunity from the Covid-19.

We can apply this model to a city with 100000 people. With complete lock-down only 1-2 people will die for every 1000.  You will have 100-200 deaths and if it is one million you will have 1000-2000 deaths.  But to get that result we assume a city should be totally lock down for at least 2 cycles of incubation period (28 days) banning all movement.

Countries adopting this type of model successfully are China, South Korea and Germany. In Sri Lanka's case there are lot of patients still unaccounted for which hinder the effect of lock-down.

*basic reproduction number (see link below)

Formula used - ((1-R0ⁿ)/(1-R0)) , n is the day 

(Special help - Shakyra Dharma)

BBN - Reactions Explained

https://sph.umich.edu/pursuit/2020posts/how-scientists-quantify-outbreaks.html

Recurrent bottlenecks in the malaria life cycle obscure signals of positive selection

Problem with statistics ?

Please don't read this if the number of deaths from Covid-19 is stressing you out.

A blogger was suggesting that we take the Reproduction number 'R0' for statistical calculations as 1.5 (minimum value). The value for my initial calculations was 2.2 (middle value for R0). Using that value, I had predicted the number of infections and deaths in the UK by the 31st of March at 25141, with an increase of 3000 cases and 380 deaths (proportional value).

I just checked the news and found out that the number of deaths is 381 and the number of infections has passed 25,000, which is very sad.

My point is that we should all insist on the government to start carrying out Covid-19 tests for everyone suspected of having the virus. If found positive, they should be sent to the hospital. Also, anyone who has tested positive for immunity should return to work in order to save the economy. Others have to stay at home and stop the spread of the virus.

There are three people I know who have passed away from this virus in UK. For me, it has already become personal.

Picture: How Scientists Quantify the Intensity of an Outbreak Like COVID-19

Is Germany doing better?

Germany seems to be doing something right among her neighbors namely Italy and Spain. Germany started separating people early on. With proper medical attention, Germany started doing tests for all the citizens who were suspected of having Covid-19. The result of this strategy is that, although the increase in infections shows an exponential nature, Germany's death rate is low.

It seems that by the end of this month Germany will reach the 60,000 (plus/minus 1000) mark for the number of infections. This is mainly due to some people who are ignoring the government's advice and shopping and travelling freely. However, the German government has now banned all travelling within states and cities. Also the fact that the number of people who have died from the coronavirus so far stands at 94. It looks like the number of deaths would be limited to around 200 plus/minus 20 by the end of this month. Well done to Germany.