How sewage could be used as an early warning sign for next Covid-19 wave
Cape Town - Health experts have warned that the Covid-19 vaccines are not a silver bullet and that the key to fighting the pandemic remains the continued wearing of masks, following public health guidelines and stronger surveillance.
The World Health Organization (WHO) regional director for Africa Dr Matshidiso Moeti said last week: “We must stick to our guns and double down on the tactics we know work so well. That is mask wearing, handwashing and safe social distancing. Countless lives depend on it.”
Provincial head of health Dr Keith Cloete agreed that on top of a vaccine, there would be the need to initiate stronger surveillance protocols and public health measures to curb the spread of coronavirus.
Stronger surveillance in the Western Cape means more scrutiny of wastewater as this remains key to tracking the progress of the pandemic.
Cloete said: “The surveillance will not lessen. It will stay the same. It will be an important marker to monitor over the coming months.”
According to the WHO “the concept of wastewater surveillance is simple. Infected individuals excrete the pathogen, which gets flushed down the toilet or washed down the drain. The pathogen, or fragments of its genes, then travel through a community’s sewage system to a treatment plant, where careful sampling can detect its presence”.
With regard to tracing of the Covid-19 spread in sewered wastewater treatment systems, senior vice-president of ABB Energy Industries Christian Cravedi said: “We know from the news that across the various phases of Covid-19 phases, wastewater analysis has proved important in understanding how the virus was spreading.
“Our solutions are designed to help monitor, in real-time, the key quality parameters and take preventive and corrective actions straight away. Being able to detect any deviation through a plant operating system can help limit or avoid the spread of a virus or any other contaminant that represents a threat for either the environment or people’s health,” said Cravedi.
When the national lockdown started, the City of Cape Town's water scientists and epidemiologists initiated a joint collaboration, the South African Collaborative Covid-19 Environmental Surveillance System (Saccess) network.
The City’s Mayco member for Water and Waste, Xanthea Limberg said: “Many people do not experience symptoms of the virus, so wastewater analyses provide a more accurate picture of the extent of the outbreak”.