
South Africa’s Covid-19 cases are “increasingly rapidly” at what looks to be “the fastest rate we have seen since the start of the pandemic,” Michelle Groome, head of the country's National Institute for Communicable Diseases (NICD), told CNN Wednesday.
Weeks after Omicron was first detected, it is now the dominant variant in some provinces, according to health authorities. In Gauteng province -- which includes the major city of Johannesburg -- the Omicron variant comprised 74% of sequences, said South Africa's Network for Genomic Surveillance on Wednesday.
The province has seen the sharpest rise in coronavirus infections in the last month, and testing is ongoing to determine the prevalence of Omicron in other districts.
Infections in South Africa appear to be surging, with around 8,600 daily cases on Tuesday, up from roughly 1,300 cases a week earlier, according to latest data from the National Institute for Communicable Diseases.
Groome said the rapid increase of cases was "concerning," adding that testing of wastewater had alerted authorities relatively early to infections in the Pretoria district.
"Two weeks ago we were seeing case numbers and positivity rates which were the lowest since the start of the pandemic," said Groome. She added that those numbers "have climbed rapidly to today" where scientists were looking at "positivity rates of over 15%."
For now, it was unclear whether the rise in infections was "due to increased transmissibility of the Omicron variant or due to immune escape," said Groome.
She added that cases had mostly been among younger people, which could be down to their increased social gatherings as schools broke up, as well as lower vaccination rates in that age group.
So far, doctors had observed "mostly mild cases," Groome said, putting it down to a mostly younger demographic presenting.
As cases move into the older population, doctors will have a better idea of "whether we are seeing reciprocal increases in hospitalizations and deaths associated with it, or whether this really is more a mild disease," Groome said.