Hilton in KwaZulu-Natal was where the country’s first confirmed case of Covid-19 was identified and it’s in the news again, this time because, GreenHill Laboratories – based in the town – is the first contract laboratory in SA and Africa to detect SARS-CoV-2 RNA in sewage as part of a commercial virus risk forensic service.
This is a significant development in tracking and dealing with the pandemic in SA – as more testing is done and the national database grows, sewage can be used to tell where Covid-19 hotspots are, making it possible to monitor the total viral load in the country’s wastewater treatment works.
The process involves taking bulk, composite samples through to a laboratory capable of meeting the needs of clients in both the public and private sectors.
The “Proof of Concept” was the culmination of a team effort spearheaded by Prof Anthony Turton of the University of the Free State and Amanzi-4-All, co-ordinated by Neil Madgwick of Praecautio, with sampling undertaken by Kevin Lindsay of Instru-Serve. The Impuma Group, through Amanzi-4-All, was instrumental in the sponsorship of the trial.
The pilot trial took sewage samples from five wastewater treatment works (WWTW) based in Gauteng that were transported to GreenHill Laboratories in Hilton. The samples were collected using automatic samplers over a period of 24 hours to optimise statistical rigour in the results.
Under the leadership of GreenHill Laboratories’ director, Dr Shaun Groenink, the samples were processed and analysed by principal molecular biologist, Dr Cara-Lesley Bartlett. The viral RNA was extracted and identified based on protocols published by the Dutch KWR Water Research Institute and the US’s Centers for Disease Control and Prevention (CDC).
The detection by polymerase chain reaction (PCR) is identical to the method being used in many medical pathology laboratories around the world. It is based on the N1 and N2 regions of the nucleocapsid gene of the virus. PCR is the amplification of small amounts of specific RNA (after transcription to DNA) to detectable levels that are then visualised by fluorescence.
Three of the five samples yielded detectable levels of viral RNA, with the laboratory working on procedures to increase the sensitivity of the test. The same five wastewater treatment works were resampled and analysed with results consistent with expectations.
The Proof of Concept demonstrates that:
**Covid-19 can be detected in wastewater
**South Africa has the capability for this testing – samples do not have to be sent to other countries for testing
**Statistically relevant sampling and timeous delivery to the laboratory are possible
**Existing protocols and kits have been used – there is no need to develop specific kits
The establishment of a Proof of Concept facilitates the development of additional parameters, such as the quantification of viral load. This additional data can be used to monitor community-wide viral load, and assess whether various mitigation strategies are working or not.
Through partnerships, the logistical supply chain from point of sample to the laboratory can now handle national-level upscaling, and Amanzi-4-All can offer this service to any client immediately, including both the public and private sectors. There has been interest in this technology from a range of roleplayers in North America, Africa, the Middle East, and Southeast Asia and the SA government, the company says.
Transforming the approach to managing Covid-19
The capacity of this South African laboratory to detect SARS-CoV-2 in sewage expedites its application by epidemiologists, public health scientists and those charged with looking after the health and safety of students, visitors and employees. This includes predicting and monitoring potential Covid-19 hotspots to focus intervention by decision-makers and public health officials in these areas, as well as assessing the true extent of SARS-CoV-2 infections.
These new sampling and testing capabilities can provide robust information to both government and private sector decision-makers in their efforts to contain the spread of the coronavirus while reopening the economy.
Rapid deployment across all sectors of society is key to limiting the pandemic’s effects
The team is expanding and optimising the value chain to include individual buildings, schools, mines and businesses.
Greenhill Laboratories’ Chairman Austin Hlongwane says: “I would personally like to commend the GreenHill Laboratories team for all the diligent effort they have put into this project. Their dedication, desire to experiment, out-of-the-box thinking and personal passion is unparalleled. As a result, I am hopeful for positive outcomes in the fight against Covid-19.”
The laboratory will continue to develop and refine the protocols and expand on their scope and application.
About Greenhill Laboratories
GreenHill Laboratories (GHL) is a testing and consulting laboratory to the agricultural, veterinary and food industries. GHL accepts biological samples, food samples, commodity samples and agricultural samples for customers’ legislative, quality and health requirements.