CAPE TOWN - As Covid-19 infections continue to climb around the country, the National Institute for Communicable Diseases (NICD) has detected the new Omicron sub-variant BA.4 in wastewater in south western Johannesburg.
On Sunday, the NICD reported 3 838 new Covid-19 cases, representing a 22.0% positivity rate.
On Saturday, the institute reported 6 527 new cases, representing a 21.5% positivity rate.
The cumulative number of deaths stands at 100 363.
According to the NICD’s latest wastewater-based epidemiology for SARS CoV-2 surveillance report, stable, sustained and new increases in the levels of SARS-CoV-2 had been observed in wastewater treatment plants in Gauteng, KwaZulu-Natal, Free State, Western Cape, Northern Cape, and North West provinces.
Variants of SARS-CoV-2 can be identified in wastewater through detection of single-nucleotide polymorphisms (SNPs) that are specific to each variant. SARS-CoV-2 is shed from symptomatic and asymptomatic persons in stool but is not transmitted by the faecal-oral route nor via wastewater.
In Gauteng, sustained increases were seen at Daspoort in Tshwane South and Rooiwal in Tshwane North over four consecutive weeks. The levels have further increased in Goudkoppies in the city of Johannesburg. In Ekurhuleni South, sustained increases over three weeks were noted in Vlakplaats while high levels remained stable in Hartebeesfontein, Ekurhuleni North.
SARS-CoV-2 levels have remained stable at the central WWTP in eThekwini in KwaZulu-Natal and Sterkwater and Bloemspruit WWTPs in Bloemfontein, Free State.
The SARS-CoV-2 levels in Borcherds Quarry and Zandvleit in Cape Town had increased over the previous epidemiological week.
Sustained increases were also noted in Homevale in France Baard, Northern Cape, and at Rustenburg WWTP in Bojanala, North West.
“Sequencing data available up to week 13 show the presence of Omicron variant in all recent samples across South Africa with evidence of the new Omicron sub-variant BA.4 present in south western Johannesburg. Whilst some mutations associated with the Delta variant were also present, the significance of these remains unclear,” the report reads.