First SA Covid-19 RNA sample extracted from sewage

HISTORY was made in South Africa this week when a commercial laboratory became the first to extract Covid19 RNA from various sewage samples.

This was done as a proof of concept after the Dutch research agency KWR entered into an agreement with the SA Business Water Chamber in April.

KWR demonstrated the potential of wastewater surveillance to identify the total viral load in a defined population in the Netherlands.

The technology breakthrough is said to have opened a new chapter in wastewater epidemiology.

Prof Anthony Turton from the Centre for Environmental Management at the University of the Free State (UFS) said it was now possible to monitor the total viral load in each of the 824 wastewater treatment works in the country.

Once the population size within the catchment area of the works is known, a calculation of the total viral load is possible, with a reasonable degree of accuracy. This accuracy would improve over time as the technology becomes more robust, UFS said in a statement.

Turton said the proof of concept was significant, because it took just eight weeks after reaching the agreement with KWR to find a laboratory with the necessary capabilities and to conduct the first tests.

The main objective was to determine whether the Dutch methodology could be replicated in South Africa without major investment into training and procurement of laboratory equipment.

Samples were taken over a 24-hour period using an automatic bulk sampler provided by a service provider at risk. A number of sewage works were sampled to emulate the complexity of a national operation should rapid implementation be required. The first samples were taken last Thursday.

These were prepared according to a precise protocol and were shipped to the laboratory hundreds of kilometres away. RNA, one of the three major biological macromolecules that are essential for all known forms of life along with DNA and proteins, was successfully extracted on Monday.

Lessons learned in the first trial were being fed back to the team in preparation for a second sampling run, a refinement of the first, that would take place shortly.