Tuesday, 26 April 2022 10:04

Prof Madhi warns against interpreting data – especially with Covid-19 positivity rate.

By Lehlohonolo Lehana.

South Africa recorded a spike in positive Covid-19 cases on Monday (25 April), fuelling further concerns of a resurgence in the coming weeks.

A total of 10,144 tests were conducted in the last 24 hours, with 1,954 new cases representing a 19.3% positivity rate. A further 30 deaths were recorded, with two of these occurring in the past 24–48 hours.

However, professor of Vaccinology at Wits University Shabir Madhi said that concerns around the rising cases need to be tempered, with resurgences predicted every four to five months between waves.

"We need to be careful about interpreting the data – especially with the positivity rate. In South Africa, we have become much more selective about who is being tested," he told news channel eNCA.

"People who are more likely to have Covid are the ones forward for testing, and the overall testing rate has decreased, so it is difficult to make head-to-head comparisons between what we are getting now and previous waves."

Madhi added that this particular resurgence is 'nothing to worry' about as it appears to be driven by the BA.4 variant,  which is the sublineage of the Omicron variant. He added that a high percentage of South Africans would have some level of immunity (as much as 85%) due to infection of vaccination.

Madhi said that a resurgence is typically classified when the positivity rate is above 10% for more than two consecutive weeks. He said this would vary by province, with Gauteng again appearing to lead in new cases.

The professor added that the focus in South Africa should not be on positivity rates but rather on hospitalisations that are 'extremely modest still'. Mahdi added that South Africans still need to be cautious, especially those in older age groups and with underlying health conditions, and should come forward for their vaccine or necessary booster shot.

Health minister Joe Phaahla said his department is tracking the 'worrying' increase in Covid-19 cases in recent days and will present its findings to the public once it has more information. Forecasts provided by the Department of Health and insurer Discovery have indicated that the fifth wave of Covid cases is most likely to occur from the end of April.

Phaahla said that the situation is actively being monitored, adding that more time is needed to determine the exact trend in infections.