Health officials say the new coronavirus variant Omicron has now become dominant in South Africa and is driving a sharp increase in new infections.
Some 8,500 new Covid infections were registered in the latest daily figures.
That is almost double the 4,300 cases confirmed the previous day.
By contrast, daily infections were averaging between 200 and 300 in mid-November, a top South African scientist told the BBC.
Omicron has now been detected in at least 24 countries around the world, according to the World Health Organization (WHO).
South Africa was the first country to detect the highly mutated new variant. Its National Institute for Communicable Diseases (NICD) has said more than 70% of all the virus genomes it sequenced last month have been of the new variant.