What the numbers say about coronavirus in South Africa

The number of confirmed Covid-19 coronavirus infections in South Africa climbed 28% to 709 by late Tuesday, with zero fatalities to date, although two patients are in Intensive Care, according to the latest figures from the government.

While trying to project the spread of the virus on the South African population is very difficult, Momentum Investments has tried to illustrate the potential trajectory of the virus without intervention, and why the robust steps taken by the government are necessary and compliance by each citizen is essential.

President Cyril Ramaphosa on Monday evening announced drastic new measures to combat the spread of the Covid-19 coronavirus in South Africa. The president enforced a three week lockdown period, beginning Thursday (26 March), at midnight, with severe restrictions on travel and movement.

“The most important number is the loss of life,” said Rowan Burger – Momentum Investments strategist. Scientists are still trying to work out what the probability of death is. It is easy to know how many have passed. However, how many were infected is more difficult to establish,” he said.

Globally, there have been 439,654 reported cases, with 19,744 deaths. 111,942 people have recovered, but 307,968 cases remain active, with 13,425 in serious or critical condition.

Italy has recorded 6,820 deaths, more than double that of China (3,281) and Spain (3,434). China has 81,218 recorded infections, followed by Italy (69,176), the US (55,081) and Spain (47,610).

South Korea tested all persons from an early stage. Italians were slower, said Burger. South Korea recorded 9,137 infections, with 126 deaths. “Those countries later to respond have tested only those visibly showing symptoms. For this reason, the number of deaths per persons infected varies based on the response in that country,” Burger said.

“We are still in the early stages of the spread of the virus and, at 24 March, the president’s announcement of the lockdown, are yet to have a fatality in South Africa.

“This makes our projection of the impact more difficult (as we do not have a handle on the true infection rate). We must assume that, in our country where there is a higher HIV, tuberculosis and diabetes existence, the mortality rates are likely to be higher.”

Both the president, and health minister Zweli Mkhize have warned that the infection rate in the country will continue to rise, with the health minister previously warning that as much as 70% of the population could contract the illness over time.

Mkhize noted that as many as 50 new infections came from a single church related gathering in the Free State.

“As we have been relatively slower to respond, the information from the countries mentioned above is more instructive. It is estimated for each tested infected person, there are nine others, who have mild symptoms or who have the virus, are able to transmit it but are unaware of this.

“This is because the virus takes up to 14 days for the symptoms to present themselves. Of importance with this number is how many people you unknowingly interact with” said Burger.

Using the sample base reported on 23 March of 402 reported cases, implied that the true number of infections at this date is about 4,000 (with 709 current cases – 7,000), said Botha. “However, to keep the numbers manageable, let’s deal with only the reported cases, bearing in mind we could multiply these by 10.”

The next key metric is the rate at which infections grow. It seems that the average response has let the number of infected double every three days. “This means that in a month, the infection rate will double roughly 10 times. (210 = 1024). Let’s keep the number at 1,000 to keep the maths easier.”

“This implies we will have 400,000 infected in a month’s time (with a large number still in incubation),” said Botha.

From preliminary experience, roughly 15% to 20% of those infected need hospitalisation. That implies 60,000 additional hospital beds are needed.

“On the assumption that our hospitals can treat those infected needing attention, the mortality rate is somewhere between 1% and 2%. This implies 8,000 deaths from those infected in the coming months (assuming we are on the higher bound of mortality). The mortality in Wuhan was 4%, due to close living conditions,” said Botha.

“This sharp increase in infections will become limited, as we may run out of persons to infect. It also assumes that we take no steps to slow the infection rate. Over time, it is predicted that 60% to 70% of the population may get infected.

“In a population of 60 million, this would be 36 million infected and 720,000 deaths. This is a truly staggering number. This estimation seems very unlikely, as certainly behaviour must change.

“But every three days the problem doubles. We don’t have the population density to reach these levels of infection and, consequently, in most worse-case scenarios, the estimation is around 200,000 deaths.”

This is exactly why government is taking draconian steps to try to curb the spread of the virus, said Botha. He said that we need to get the infection rate down from doubling every three days – and to do this, we need to:

  • Make sure those who suspect they are infected (the nine in 10) self-isolate to make sure they do not pass it on.
  • Practice regular hygiene (hand washing and avoid contact with the face) and social distancing to reduce the doubling rate of the infection.
  • Make sure the total number of persons infected remains at a manageable level (the often-spoken-about flattening of the curve) so our hospitals and medical staff can tend to those who need treatment.
  • When circumstances change, people change their behaviour. It is therefore critical that we stop the spread of the virus. China has successfully managed to have the number of those cured exceeding those getting infected.

Read: South Africa’s coronavirus lockdown does not mean a ‘shutdown’: government

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What the numbers say about coronavirus in South Africa