Evaluation of three viral concentration methods for detection and quantification of SARS-CoV-2 in wastewater

Abstract

Wastewater-based epidemiology (WBE) could be useful as an early warning system for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic spread. Viruses are highly diluted in wastewater. Therefore, a virus concentration step is needed for SARS-CoV-2 wastewater detection. We tested the efficiency of three wastewater viral concentration methods: ultrafiltration (UF), electronegative membrane filtration and aluminum hydroxide adsorption–elution. We spiked wastewater with inactivated SARS-CoV-2 and we collected 20 other wastewater samples from five sites in Tunisia. Samples were concentrated by the three methods and SARS-CoV-2 was quantified by reverse transcription digital PCR (RT-dPCR). The most efficient method was UF with a mean SARS-CoV-2 recovery of 54.03 ± 8.25. Moreover, this method provided significantly greater mean concentration and virus detection ability (95%) than the two other methods. The second-most efficient method used electronegative membrane filtration with a mean SARS-CoV-2 recovery of 25.59 ± 5.04% and the least efficient method was aluminum hydroxide adsorption–elution. This study suggests that the UF method provides rapid and straightforward recovery of SARS-CoV-2 in wastewater. HIGHLIGHTS Spiked wastewater with inactivated SARS-CoV-2 was used to compare the recovery of three viral concentration methods.; Untreated municipal wastewater samples collected from five sites in Tunisia were used to compare the detection sensitivity of the three viral concentration methods.; UF showed the best recovery and virus detection ability in wastewater samples.;

Keywords

• concentration methods
• covid-19
• sars-cov-2
• wastewater-based epidemiology (wbe)
• wastewater virus