An increasing share of SA's Covid-19 cases are the BA.4 and BA.5 sub-lineages of the Omicron variant, suggesting those might have a growth advantage over others, Prof Helen Rees said on Thursday.

Rees added at a World Health Organisation news conference that despite rising Covid-19 infections, SA was so far not seeing a huge increase in mortality or intensive care admissions.

The WHO said earlier that Africa is seeing an uptick in Covid-19 cases largely driven by a doubling in cases reported in SA.

“This week new Covid-19 cases and deaths on the continent increased for the first time after a decline of more than two months for cases and one month for deaths,” Benido Impouma, director for communicable and non-communicable diseases at the WHO's Africa office told an online news conference.

“This uptick is largely associated with the increasing number of cases reported from SA as the country enters its winter season when respiratory illnesses become more prevalent,” Impouma added.

Africa has been experiencing a lull in Covid-19 cases, with the WHO earlier this month pointing to the longest-running decline in weekly infections on the continent since the start of the pandemic. But last week cases started to pick up in SA — the country that has recorded the most infections and deaths in Africa to date — and health authorities are monitoring for signs of a fifth infection wave.

“Just in the last week the country's (SA's) cases have doubled, and there is a small increase in hospitalisations,” the WHO's Impouma said.