Corona virus spread in France: multi-agent based simulation

I am writing to share my opinion and speek about the corona epidemic spread worldwide and especially in France where the actual number of infected persons is about 200 ...and I believe that the real number is much higher than we can expect....!

 Corona is not like the classical seasonal influenza epidemic because they have not the same economical and social effects...when you have a flu..you have a flu and just it.... if you catch corona you will be already considered as someone who had plague...with classical flu we did not resort to massive isolation...massive quarantine...internal border controls have never been imposed...businesses and schools were not closed for weeks....and economic activity was not reduced.....

Covid-19 and seasonal flu are different because they have not the same spread rate and the same fatality rate...For example, a group of five infected people could spread the corona virus to about 368 people over just five cycles of infection but only about 45 people might be infected by flu in the same scenario (source). Now, Covid-19 is 20 times more deadly than the flu with a fatality rate of about 2.3% (source) . This percentage will surely increase when the size of the outbreak will increase as the virus is spreading worldwide.... 

Face to this unknown virus, people in France have now two social attitudes:  

- Fear,  as 61% of French people worried about themselves and their families  (we are not yet speaking about Corona-phobia)

- Indifference...

 The Fear of the virus spreading is spreading at much faster rate than the virus itself...It is a normal humain behavior!

I am one of the people who are worried and I want to speak about this virus because I think we should take this problem more seriously....

In fact I am not just worried about myself and my family...But, as a researcher,  I am also disappointed ...I am thinking about  "Crisis Management and Decision Making"...I believe that governments  worldwide should act now...before the situation will be uncontrollable... 

I am haunted by many questions...what are the best decisions to reduce the spread of Covid-19 at this stage ? should we apply a pandemic strategy ( when I think about cooperative games :p .... )? 

 Should we resort to selective quarantine (people with more than 60 years for example) ? Should we resort to e-learning...? resort to teleworking for all people who can work remotly... ? Consulting Doctors Online (in case of simple illnesses)? what about transport and intellegent organization to avoid rush hours .... ?  

And what about the healthcare system ! is it strong enough to cope with thousands or millions of infected people in a short time period... ? In France, people aged  60 or more represent more than 26% of the population  (more than 17 million (source))...

According to the latest data provided by china, for poeple having 80 and older, the death rate was 14.8%, compared with 8.0% for those ages 70 to 79; 3.6% for those ages 60 to 69; 1.3% for those ages 50 to 59.... I let you imagine the situation in case of  very wide virus spread.

I am not a specialist in biology or viruses spread but I started to simulate Covid-19 spread using a multi-agent simulation based model. I generated population samples with the same statistical properties as the French population. This basic model is based on some parameters like the fatality rate by age (data provided by china), average social centrality (the average number of people in the social circle of each person), the virus spread chance, the size of the population and the size of the initial infected outbreak. In this simulation, people can be susceptible, infected, resistant or dead. As a result, we can get the percentage of each proportion. 

Numbers are talking better than words! If measures are not taking to control the virus spread, the percentage of infected people and the percentage of deaths will be very important!

Let's take the example of a small population (size = 1000) with initially 10 infected persons. If each person have a direct social contact with about 20 persons (in average)  and if the spread rate of the virus is equal to 20%, more than 75% of the population will be infected  and the death rate will be more than 3%.

Initial Setup: Population size = 1000; Initially infected/outbreak size = 10;

                                                    Social Centrality =20; Virus spread rate = 20%

Virus spread : a screenshot of the simulation

(Social Centrality = 20)

Simulation Results (Social Centrality = 20)

To see the effect of limiting social contact on the virus spread, I did the same simulation but with   Social Centrality = 3, the results are significantly better. The percentage of infected persons and death rate  have respectively reduced to 20%  and 1.2%

Virus spread : a screenshot of the simulation
(Social Centrality = 3)

Simulation Results (Social Centrality = 3)

There is surely a lot to learn about the virus..without cooperation and preventive decision making strategies, the social and the economic toll will be heavy....

Finally, to end with a positive note, we should not also forget that pharmaceutical companies across the world are trying to develop coronavirus vaccines for treating the contagious infection  :)  A pandemic could be also brought under control (like SARS) following an isolation strategy and controlling all passengers travelling by air from affected countries...

Environment and climate have an important role in virus spread...hope that warming temperatures this spring help to reduce the propagation...

Keep calm, don't forget to wash your hands regularly and may God bless you all :)