Barely a day has passed since President Biden announced his new measures to help the US brace for the coming omicron-driven COVID surge, and already, South Africa’s case numbers are drawing scrutiny for a sharp drop in new cases.
After touching a new single-day high of nearly 27K new cases nationwide on Thursday, South Africa’s numbers dropped to about 15.424K on Tuesday. According to the AP, South Africa – the “forefront” of the global omicron wave – could be ending before it even starts, despite relatively low uptake of vaccines. Scientists say acquired immunity through infection might have something to do with the trajectory, although distortions and an unevenness in number publishing between different regions of the country could also be a factor.
But there is one key detail to suggest this isn’t due to some data quirk: In Gauteng province, South Africa’s most populous with 16MM people, which has been closely watched since the omicron variant first emerged last month. In addition to being the most populous province in the country, its also home to the largest city, Johannesburg, and the capital, Pretoria, the decrease started earlier and has continued.
“The drop in new cases nationally combined with the sustained drop in new cases seen here in Gauteng province, which for weeks has been the center of this wave, indicates that we are past the peak,” Marta Nunes, senior researcher at the Vaccines and Infectious Diseases Analytics department of the University of Witwatersrand, told The AP.
“It was a short wave…and the good news is that it was not very severe in terms of hospitalizations and deaths,” she said. It is “not unexpected in epidemiology that a very steep increase, like what we saw in November, is followed by a steep decrease.”
Gauteng Province saw its numbers start sharply rising in mid-November. Scientists doing genetic sequencing quickly identified the new, highly mutated omicron variant that was announced to the world on Nov. 25.
And the country’s R-naught rate, which has been falling since the start of December, has finally broken back below 1, seen as a critical divide between spreading and slowing.
In another sign that the country’s omicron surge may be receding, a study of health care professionals who tested positive for COVID at Chris Hani Baragwanath hospital in Soweto shows a rapid increase and then a quick decline in cases.
“Two weeks ago we were seeing more than 20 new cases per day and now it is about five or six cases per day,” Nunes said.
But, she said, it is still very early and there are several factors that must be closely watched.
South Africa’s positivity rate has remained high at 29%, up from just 2% in early November, one sign the virus is still circulating among the population at relatively high levels.
The big question now is whether the holiday season in South Africa, where people often travel and visit family, leads to increased viral spread across the country. If it does, cases could turn higher again in the New Year.