Experts say that South Africa is experiencing a sudden rise in Covid-19-related cases, which could be due to another form of coronavirus.

The country had seen a drop in cases since February. Salim Abdool Karim who advised the government in its Covid-19 response, stated that cases have been increasing rapidly due to a new omicron-subvariant called BA.4.

Abdool Karam, a University of KwaZulu-Natal public health specialist, stated that there has been a decrease in the number of hospitalizations but not an increase in deaths.

South Africa now has just above 6,000 Covid-19 cases per day. This is up from just a few hundred only a few weeks back. Official figures show that the proportion of positive test results increased from 4% to 19% on Thursday. Coronavirus spread also has seen an increase in wastewater surveillance.

Although the new mutant seems to have quickly overtaken the original Omicron, Abdool Karim stated that it was too soon to know if BA.4 will cause an entire wave.

The new version, however, is noteworthy because it was introduced first in South Africa in November 2005 and Botswana in May 2006. It then spread around the globe.

Helen Rees (executive director of Reproductive Health and HIV Institute at University of Witwatersrand) said there is a troubling trend. Children end up being admitted to hospitals first, as they were during the initial omicron surge.

Experts think that BA.4 may be more transmissible then both the original Omicron variant as well as an omicron cousin known simply by its name, BA.2. The new mutation is still being studied by scientists, WHO stated in a recent report.

Abdool Karim stated that South Africa may have experienced a surge in its recent Easter, Ramadan or Passover holiday celebrations, as well as massive flooding along the Durban coast.

BA.4 is being used in some other countries but it’s unclear if it will “become a global dominant variant.” He said.

It has not yet made its way into the U.S. where BA.2 is still the predominant strain, and BA.2.12.12.1 (its descendant) is growing in popularity. According to TheCDC, the descendant spreads faster than the previous viruses and was responsible for 29% of U.S. Covid cases during the week ending September 2. U.S. Centers for Disease Control and Prevention.

Can BA.4 out-compete BA.2.12.1?

Johns Hopkins University infectious diseases expert Dr. Stuart Campbell Ray said that the variants of both are being spread in various populations and that he does not have any data to support “a solid direct comparison.”

South Africa has been the African country with the highest concentration of Covid-19, since the beginning of the pandemic. South Africa, with 60 million inhabitants and less than 5% Africa’s total population of 1.3billion, has been responsible for more than 25% of Africa’s 11.4million reported cases. It also accounts for nearly half the 252,000 African deaths. Experts believe this may be due to South Africa’s better public health system, which keeps more records about hospitalizations and deaths that other African countries.

According to statistics from the government, more than 44% are currently vaccinated against Covid-19.

Benido Impouma is a WHO official for Africa. He said that the recent surge shows people need to remain vigilant and adhere to safety measures like wearing masks and washing their hands.