By Lehlohonolo Lehana.

The National Institute for Communicable Diseases (NICD), reports 4,146 new COVID-19 cases that have been identified in South Africa, which brings the total number of laboratory-confirmed cases to 3,780,444. 

The majority of new cases today are from Gauteng (53%), followed by Kwa-Zulu Natal (23%). Western Cape accounted for 11%; Free State accounted for 4%; Eastern Cape, Mpumalanga and North West each accounted for 2% respectively; and Limpopo and Northern Cape each accounted for 1% respectively of today’s new cases.

This increase represents a 18.3% positivity rate.

The proportion of positive new cases/total new tested today is (18.3%), and is lower than yesterday (21.1%). The 7-day average is (18.3%) today, and is higher than yesterday (18.0%).

Today, the NDoH reports 4 deaths that occurred in the past 24 – 48 hours. This brings the total fatalities to 100,355 to date.

New omicron sublineages, discovered by South African scientists earlier this month, account for about 70% of new coronavirus cases in South Africa and the strains appear to be more infectious than predecessors.

The BA.4 and BA.5 sublineages appear to be more infectious than the earlier BA.2 lineage, which itself was more infectious than the original omicron variant, Tulio de Oliveira, who runs gene sequencing institutes in the country, said on Twitter.

Before we move on, let's be clear that, at present, our main scenario for Omicron BA.4 and BA.5 is that it increases infections but that DOES NOT translate into large hospitalizations and deaths as high population immunity in SA and empty ICUs.

— Tulio de Oliveira (@Tuliodna) April 28, 2022

"Our main scenario for Omicron BA.4 and BA.5 is that it increases infections but that does not translate into large hospitalizations and deaths," he said in a series of Tweets.

A rapid increase in infections in the last 2 weeks was due to BA.4 and BA.5. Albeit coming from a low number. The 6,000 infections yesterday are underestimated as the test positivity ratio is around 20%. SA did not have a BA.2 Omicron wave-like Europe but only a large BA.1 wave. pic.twitter.com/8b4PZe6CkW

— Tulio de Oliveira (@Tuliodna) April 28, 2022

South Africa yesterday recorded 6,372 new cases with a positivity rate of 21.1%. That compares with 581 cases and a positivity rate of 4.5% on March 28.The National Institute of Communicable Diseases has said hospitalizations and deaths are rising, albeit slowly.