Coronavirus Critical Curves: Crucial Insights from Mathematical Modelling

Nashon J. Adero
11 min readApr 4, 2020

Analysis of trends, perspectives and lessons for Kenya and Africa

The emerging equation of growth in worldwide COVID-19 cases over the period 21st March –3rd April 2020. Data source: Worldometer

Grim Coronavirus Statistics: Summary of Key Metrics

We are starting the weekend in Kenya with more than a hundred confirmed cases of the novel coronavirus infections. The confirmed global cases have exceeded one million. Taking the reported cases of infections, the average global death rate of 5% and the average recovery rate of 21% paint grim statistics. These global figures, so far, translate into 7 deaths for every one million people on Earth! From research into the latest data from 21st March 2020, the business-as-usual scenario gives the global equation Y = 315250exp(0.1t), which projects the worldwide coronavirus cases to hit 1.5–1.7 million by 7th April 2020. This insight introduces a new week likely to record 2 million coronavirus cases worldwide by 12th April 2020.

This study report has covered 14 countries which have posted enough data for trend analysis, including China, using the data from 10th January to 31st March 2020. Over the study period for these countries, the observed daily growth rates in the exponential phases varied from 11% in Hong Kong to 26% in the USA, staggering rates by any measure. Spain’s daily rate of 20% over the period has been much higher than Italy’s 13%, portending a high likelihood of Spain eventually surpassing Italy in COVID-19 cases. Based on the study scope, it has been taking on average about a month (33 days) for the critical exponential phase of growth in coronavirus infection cases to commence. Nearly three weeks (17 days) has been the average time of stay of the critical exponential phase of growth in coronavirus infection cases, followed by a marked drop off the exponential trajectory. The lesson for Kenya and the rest of Africa is that, depending on the efficiency and effectiveness of interventions, it may take a wide range of two weeks to two months for different countries to start recording an exponential rise in COVID-19 cases.

Kenya started recording a sharp rise in confirmed coronavirus cases on 27th March 2020 (with a total of 31 cases then). From the data range on confirmed cases in Kenya covering 27th March to 3rd April 2020, Kenya’s simulation curve becomes Y =

Nashon J. Adero

A geospatial and systems modelling expert, lecturer, youth mentor and trained policy analyst, who applies system dynamics to model complex adaptive systems.