New SA coronavirus statistics raise concerns about the extent of blocking: what you need to know

Health Minister Zweli Mkhize revealed that South Africa has registered 2,605 cases of COVID-19, an increase of 99 cases since yesterday.

Most of these cases come from the three epicenters of the coronavirus in South Africa: Gauteng, Cape Town and Durban.

The total number of cases in Gauteng is now 969, followed by the Western Cape with 675 and KwaZulu-Natal with 539.

The growth in the number of COVID-19 cases is closely related to the number of tests performed. The number of coronavirus tests conducted to date is 95,060, a daily increase of 4,545.

Mkhize also revealed that there were 14 new deaths attributed to COVID-19 in South Africa, bringing the total to 48.

The following table shows the total number of coronavirus cases by province.

Average number of new daily coronavirus cases

Professor Salim Abdool Karim, president of the advisory group COVID-19 of the Minister of Health, previously said an important figure to see is the average number of new daily coronavirus cases.

This figure shows if the block has been effective in slowing down the spread of the virus. It will also inform the decision on whether to extend the national blockade or not.

Last week, the average number of new daily coronavirus cases was 67. The 95% confidence interval for this number is 45 to 89 cases per day.

Karim provided four scenarios for the average number of daily cases between April 10-16.

1. Equal to or greater than 90: continue blocking.
2. 45 to 89 and the ratio of positivity to detection (CHW) is above 1 in 1,000 – continue blocking.
3. 45 to 89 and the ratio of positivity to detection (CHW) is equal to or less than 1 in 1,000: easy closing.
4. Below or equal to 44: facilitate blocking.

Karim explained that this set of criteria provides South Africa with clear guidance on how to deal with the blockade.

Passive and active cases.

Looking at the total average number of new daily coronavirus cases in South Africa, the same number used by Karim for his analysis points to an extension of the block.

The average number of daily cases between April 10-16 is 95.9, higher than the threshold of 90 cases where the block should continue.

This, however, does not mean that the lock will be extended. There is more to the average number of new daily cases than meets the eye.

Karim explained that the criteria he listed is for passive cases and should exclude cases identified through active detection.

Passive cases refer to people who have contracted the virus and went to the test after showing symptoms.

This is what happened during the first weeks in the country, and to compare “apples to apples” only passive cases should be used to match Karim’s criteria.

Thousands of “active screening” tests have also been conducted in South Africa, but the Department of Health does not provide a breakdown or case numbers based on active versus passive tests.

Karim said that differentiating between “passive and active cases” is a key issue the committee is currently dealing with.

If there is a significant number of active cases among the total of new cases this week, this can reduce the average number of new daily cases below the threshold of 90 cases.

Current situation for the total of new cases

The table below shows the average number of new daily cases between April 10-16.

The red line, in 90 cases, is when the block must continue. The green line, in 44 cases, is when the blockage should be relieved.

For this comparison, MyBroadband used the total number of new daily cases, the same number that Karim used for his calculations in the last five weeks.

Therefore, active cases have not been removed, as the breakdown of active and passive cases has not been published.

While there are understandable concerns about a block extension due to Karim’s criteria, it should be noted that there is no official government plan to do this.

Minister for Cooperative Governance and Traditional Affairs Nkosazana Dlamini-Zuma said Currently the government is not sure what will happen at the end of the month.

“We do not know for sure if the blockade will end on April 30. Even if it does, we cannot open the floodgates,” he said.

Now Read: New Coronavirus Statistics in South Africa Possible Bad News for the Block