top of page

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.

Data sources:

    - Johns Hopkins University CSSE: 

This dashboard is developed and maintained by a team of student volunteers.

We request donations to cover stipends for those students experiencing hardships

in this time of lockdown. Donations from South African tax payers are tax deductible.

SIRD Model Parameters
bottom of page