SA's new 'R number' shows the lockdown worked, say scientists

This means every infected person is passing on the virus to around 1.5 people, so the number of new cases is increasing.

In the four provinces where there are enough cases to calculate an R number, the Western Cape's is the highest, on average.

The NICD analysis, which comes with several caveats, says the five weeks of level 5 lockdown which began on March 26 “substantially reduced the national R, likely contributing to substantially slowing the progression of the epidemic”.

But the fact that R remained above 1 meant transmission of Covid-19 was continuing, and “further easing of lockdown restrictions may be associated with increases in R in different provinces as contacts between people increase”.

“Therefore, it is important to interpret these findings together with data on testing and other sources of data on transmission.

“In addition, caution should be exercised in interpreting comparisons between different time points and provinces as these could be affected by different testing practices.”