Wastewater surveillance could identify hotspots before official caseloads rise
The South African Medical Research Council has announced an “early warning system” for Covid-19 hotspots based on analysing wastewater for traces of the virus.
An infected individual sheds viral particles in their stool. By monitoring sewage for such particles, disease surveillance teams can predict outbreaks up to a week before they are visible in official testing data.
The SAMRC launched its SARS-Cov-2 wastewater surveillance dashboard on 17 November. It will collect wastewater weekly and screen it for RNA presence of the novel coronavirus.
The programme will be rolled first out in areas of the Western Cape, Eastern Cape and Limpopo. It will later be extended to Gauteng. The Eastern Cape has seen a spike in cases in recent weeks, sparking fears of a second wave of infections.
“We are very excited about the prospect of curbing Covid-19 transmission and saving lives using this technology,” said Glenda Gray, the SAMRC president, in a statement.
Angela Mathee, an SAMRC researcher, said a benefit of wastewater screening is that it can identify both symptomatic and asymptomatic cases down to community level. Wastewater monitoring has already helped identify viral spikes in the city of Cape Town and the Breede River Valley, both in the Western Cape, she said.
Renee Street, another SAMRC researcher involved in the project, added: “We hope that relevant public health authorities will be able to use the results to mount timeous interventions to reduce community spread of Covid-19.”
The SAMRC says its wastewater surveillance system could be used to track other viruses in future.
The project aims to build research capacity in historically disadvantaged universities. “Students and staff from the Universities of Venda and Fort Hare have already been trained in the laboratory methods while trainees from Sefako Makgatho and Walter Sisulu universities will soon join this group,” said Mongezi Mdhluli, an SAMRC executive committee member.