(Published - 23 June 2020)
With COVID-19 disrupting nations around the globe, everyone wants to know what to expect in the future. That’s why University of the Western Cape Professor Nico Orce has been modelling the evolution of the pandemic with international collaborators - and will be exploring what they found in a webinar on Thursday, 25 June 2020.
“We have been monitoring the evolution of the COVID-19 pandemic in many countries since its origins in Wuhan, China,” Prof Orce explains. “In the process, we have developed new epidemiological models based on the well-known Susceptible-Infected-Recovered (SIR) model. These extensions to the SIR model are based on death cases, which are confirmed by governments regularly throughout the world.”
The COVID-19 pandemic has ignited interest in mathematical models, and many relevant manuscripts have been submitted for peer-review all over the globe. The global models considered in this work, outlined in a recent paper on Global analysis of the COVID-19 pandemic using simple epidemiological models, present some differences with respect to other existing models, and provide an elegant way to distinguish between the scary exponential phase and the normal phase, where the flattening of the curve is observed.
“We developed simple epidemiological models that anyone can use,” Orce explains. “Despite the complexity of the system, the simplest of the models, the D (for Death) model reproduces very well the spreading of the virus at an early stage up to the pandemic peak, and it's an important guide for more complicated models. Furthermore, it’s based on death numbers which are more reliable than infection numbers, which are more difficult to know unless you test the whole population.”
Prof Orce’s model has been tested and retested, as he and his collaborators have kept a close eye on how it matches and diverges from the reported virus patterns in a variety of countries.
“You don't see many models out there where incoming data are used to characterize the evolution of the pandemic. This is possible because we solved analytically the complex transmission-dynamics system of equations by using a parameterized solution, which yields the Death function. The latter can be used to fit to data.”
“Eventually all models are wrong, and that’s especially true for models that involve many human beings” Prof Orce notes. “But that’s actually a good thing. Deviations from the models can tell us more about aspects originally ignored by a particular model: the lockdown effect or spatial migration, for example.”
Graphs generated from the model are updated every day and shared on social media, and people contribute to make graphs more user-friendly for everyone to understand.
“This has been a very pleasant surprise to me. Many people - including me - sometimes have the feeling that social media is full of rubbish. But we have been using it more often lately to motivate people during these hard times, and soon many nuclear physicists from all over the world were contributing to the development of the model, and other physicists were using it as computer practicals and science outreach.”
People all over the world are learning how to read and interpret these complicated graphs, how to do the Maths, plot and fit data to a model, and about the limitations of epidemiological predictions.
The webinar will focus on South Africa, but will also explore the Covid-19 evolution in other countries. Prof Orce will present model predictions regarding the exponential phase, flattening of the curve, pandemic peak, end of the pandemic, as well as considering the limitations of our predictions in this very complicated system.
“At times like these, we need to think both locally and globally,” says Umesh Bawa, Director of International Relations at UWC. “UWC is collaborating internationally to encourage bi-directional knowledge exchange between the Global South and the Global North - and to have African voices lead on issues of global and local importance. We need to work together now, and let that be a model for the internationalization imperative in the future.”
UWC Webinar: Global analysis of the COVID-19 pandemic using simple epidemiological models
Date: 25 June 2020
Time: 16:00 – 17:30
Webinar Link: https://uwc.zoom.us/j/93139337983