History was made in South Africa this week when a commercial laboratory became the first to extract COVID-19 RNA from various sewage samples in the country. This was done as a proof of concept, after the
Dutch research agency KWR entered into an agreement with the
SA Business Water Chamber on 9 April this year.
It was KWR that first demonstrated the potential of wastewater surveillance to identify the total viral load in a defined population in the Netherlands. This technology breakthrough has opened a new chapter in wastewater epidemiology on a global scale.
Prof Anthony Turton from the
Centre for Environmental Management at the University of the Free State (UFS) says it is now possible to monitor the total viral load in each of the 824 wastewater treatment works in South Africa. 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 will improve over time as the technology becomes more robust.
Rapid deployment of technology
Prof Turton says this proof of concept is 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. This is a rapid deployment of technology necessitated by the urgency of the COVID-19 pandemic. The source of funding for this demonstration was the private sector, so no taxpayer money was used. The proof of concept was deliberately designed to achieve two specific objectives. 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. The secondary objective was to understand the logistical complexities of sampling at multiple sewage works in one province, and then safely transporting those samples to the laboratory in another province. This emulates what will be needed if this methodology is adopted by government and rolled out across all provinces as required.
Taking samples
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 on Thursday 4 June. These were prepared according to a precise protocol and were shipped to the laboratory hundreds of kilometres away. The samples were prepared according to the stringent requirements of the protocol, and COVID-19 RNA was successfully extracted on Monday 8 June. Lessons learned in the first trial are being fed back to the team in preparation for the second sampling run that will take place shortly.
Prof Turton, who serves in a facilitating role and in different capacities with each of the critical components of the overall value chain, is the man in the middle tying this whole process together. This is also a demonstration of the value of a university working in close collaboration with both government and private sector partners towards a common objective. It is part of the Public Private Growth Initiative (PPGI), where the private sector works closely with the state to deliver core services needed to create employment opportunities as a matter of growing urgency.
Determining if the total viral load is increasing or decreasing
The second sampling run, which is about to be launched, will be a refinement of the first. Lessons learned during the logistical exercise will be applied to streamline the operation and generate an accurate costing of the service. By comparing the data for each sampling sequence, it will be possible to determine with a considerable degree of accuracy whether the total viral load in a given population is increasing or decreasing. When applied to multiple sewage works, it will be possible to identify hotspots for appropriate government intervention. This technical capability will provide robust information to both government and private sector decision-makers as they navigate their way through the complexity of a shutdown and phased re-opening of the national economy. Rapid upskilling of suitably qualified personnel will be needed, and the UFS will be playing a role in that process.