The modelling of how many people would contract Covid-19 and die was “flawed and illogical and made wild assumptions”, says Prof Shabhir Madhi, the former head of SA’s National Institute for Communicable Diseases (NICD).
It’s an important claim not just because of Madhi’s stature (he also co-ran the SA Medical Research Council), but also because the Covid-19 model, which suggested between 87,000 and 350,000 deaths, was instrumental in the government’s decision to implement a lockdown
The government’s initial model also predicted that 600 Covid-19 patients would need treatment in intensive care units (ICU) in SA by April 1. But by April 18, the last publicly released figures showed there were 32 Covid-19 patients in ICU.
While the lockdown would have slowed the spread of the disease, it had only been in place for four days by April 1, so this was likely not the reason why there were so few ICU patients.
Madhi says the initial modelling and fatality estimates were “back-of-envelope calculations”.
The models were prepared by the SA Centre for Epidemiological Modelling & Analysis (Sacema) at Stellenbosch University, as well as the NICD. They used data from Wuhan, the Chinese city where the outbreak began.
The Sacema model modelled its fatality projections around different scenarios in which 10%, 20% and 40% of the population contracted the virus.
Madhi says he raised problems with the model at the time. Nowhere in the world – not even in Wuhan – had 10% of the population contracted the virus. “I told them that at the start, this is implausible,” he tells the FM.