Detection and quantification of SARS-CoV-2 in wastewater using a mobile laboratory setting

This study evaluated a point-of-care device for wastewater-based epidemiology (WBE) of SARS-CoV-2 circulation. WBE is a critical tool but faces challenges such as laboratory infrastructure, sample transport, skilled personnel, and time-consuming methods. Currently, a rapid, portable solution for wastewater surveillance is lacking. From June to September 2022, the performance of the GeneXpert instrument was compared with an established in-house method for detecting SARS-CoV-2 in 151 wastewater samples across laboratory, field, and mobile testing environments. In the laboratory setting, GeneXpert showed 100% agreement in detection, with 94.6% of positive samples displaying a viral load difference of ± 1 log compared to the in-house method. Field testing demonstrated 90% agreement, with 92.6% of GeneXpert-positive samples showing similar log differences. In mobile testing, GeneXpert detected 62.5% of samples, and testing faced technical issues. Overall, GeneXpert displayed a limit of detection of 12 cpml⁻¹ with results available in under an hour, making it a promising tool for rapid and deployable wastewater testing. This requires further validation while addressing technical challenges related to field and mobile settings.