Virus thrives in wastewater systems

The Medical Research Council (MRC) SARS-CoV-2 wastewater surveillance project has detected a three-week-long surge in Gauteng, as well as hotspots in Gqeberha and Cape Town.

The project monitors the prevalence of SARS-CoV-2 viral loads at 70 wastewater treatment plants across four provinces: 20 plants in the Eastern Cape, nine in Gauteng, eight in Limpopo and 32 in the Western Cape.

With the third wave of infections still rising, here is what this week’s results tell us:

In Gauteng, the MRC’s programme monitors nine treatment plants in and around Tshwane. Johannesburg is surveilled by the National Institute of Communicable Diseases, who do not provide public data at present.

But the current data presents a stark picture. Six of the nine wastewater treatment sites reported the very highest degree of SARS-CoV-2 prevalence for the last three weeks in a row.

In the Eastern Cape across the eight Gqeberha plants, surveillance data suggests infections are on the rise. Two plants have risen to the highest prevalence category this week, and two more are in the second-highest category.

Prevalence in Limpopo is low in all but one of the eight wastewater sites. Wastewater samples are at category five at Ga-Kapane, in the Mopani District Municipality. The next-nearest plant in Tzaneen, 22km to the south, is in the lowest category of SARS-CoV-2 detection.

The Western Cape has 11 plants showing the very lowest levels of SARS-CoV-2 prevalence. There are just two plants at the highest category of prevalence and two more at category four. –