The Institute for Water and Wastewater Technology (IWWT) at the Durban University of Technology (DUT), which is at the forefront of SARS-CoV-2 wastewater surveillance in Southern Africa, has revealed that the recent civil unrests in KwaZulu-Natal were a COVID-19 super spreader event, that contributed to a substantial spike in COVID-19 infections in the province. Thousands of people were in confined spaces for long periods of time, many without masks or any form of social and physical distancing.
According to the IWWT Director, Professor Faizal Bux, prior to the civil unrest, the average number of new cases per day in a 7-day period was 1366 for KZN and 449 for the eThekwini Municipality. However, clinical data from 31 July 2021 reports that the number of new infections in a 24-hour period in KZN reached 2239, with 1007 of this stemming from the eThekwini Municipality. He said that the violent riots and looting, which lasted 9 days, had significantly impacted on KZN’s response to the COVID-19 pandemic and it now places strain on an already stressed healthcare system.
“As of the 5th of August 2021, 2667 and 1280 new cases per day were reported for KZN and eThekwini Municipality respectively, clearly indicating that the protests were a COVID-19 super spreader event which contributed to the spike in COVID-19 infections. KZN is currently in the midst of the third wave of the COVID-19 pandemic. The current wave is driven by the Delta variant which is said to be 97% more transmissible than the original strain first identified in Wuhan and 60% more contagious, when compared to other variants currently in circulation globally,” said Professor Bux.
Furthermore, Prof Bux explained that the closure of diagnostic laboratories during the unrests meant that there was significant underreporting in the number of COVID-19 infected individuals in KZN from 9 July – 17 July 2021.
“Any backlog in clinical data would have been reported from 19 July onwards – when laboratory personnel returned to work. The effect of the civil unrest on COVID-19 infections would have only manifested itself in clinical data 7 to 14 days later. Prior to the civil unrest, the average number of new cases per day in a 7-day period was 1366 for KZN, and 449 for the eThekwini Municipality,” said Prof Bux.
Unpacking IWWT’s findings, Prof Bux said that Wastewater Based Epidemiology (WBE) had proven to be an excellent tool to determine COVID-19 infection levels in populations.
He said their monitoring of the Central Wastewater Treatment Plant (CWWTP) on a weekly basis has resulted in the following key findings:
- The average copy number of SARS-CoV-2 (N2) gene per 100ml had remained constant for 3 weeks prior to the civil unrest (average of 2.7 million copies/100ml).
- An almost 6-fold increase in copy numbers was observed approximately 2 weeks after the protests (average of 12.7 million copies/100ml), in line with reported spike in clinical data confirming the occurrence of a super spreader event. However, the percentage change over 7 days in clinical data is lower than that of WBE data.
- WBE data should be considered a more accurate representation of COVID-19 infections at a community level than clinical data, as clinical testing came to a halt during the unrest while WBE testing did not.
- WBE data also suggests that there is a greater number of infected individuals in the metro than what is clinically reported and anticipates a further increase in clinical case numbers in the days to come.
Pictured: Professor Faizal Bux.