COVID-19 Global SIRD Modelling
SIRD model is a method of mathematical modelling for infectious diseases. The model consists of four compartments:
S, I, R and D which represent the number of susceptible, active cases, recoveries, and fatalities respectively. The four variables, S(t), I(t), R(t), and D(t), represent the numbers of people in each component at a particular time (day).
We use the numbers from Johns Hopkins University.
The Active cases = Total Cases - Recoveries - Fatalities or I(t) = Total Cases - R(t) - D(t)
The Infection rate β between S and I, the recovery rate γ between I and R, and the fatality rate d between I and D are below.
In addition, R0, which is defined as β/(γ+d), is called the basic reproductive ratio. This ratio is derived as the expected number of new infections from a single infection in a population where all subjects are susceptible. It means that the numbers of Infectious tend to decrease when R0 is less than 1 and increase when R0 is larger than 1.
- Johns Hopkins University CSSE: https://coronavirus.jhu.edu/map.html