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

Area of Science:

• Environmental microbiology
• Public health surveillance
• Molecular diagnostics

Background:

• Wastewater-based epidemiology (WBE) is crucial for monitoring infectious diseases like SARS-CoV-2.
• Current WBE methods face challenges including infrastructure, transport, personnel, and time.
• A need exists for rapid, portable solutions for wastewater surveillance.

Purpose of the Study:

• To evaluate the performance of a point-of-care device (GeneXpert) for SARS-CoV-2 detection in wastewater.
• To compare the device against an established in-house method across different testing environments.
• To assess the feasibility of rapid, deployable wastewater testing.

Main Methods:

• 151 wastewater samples were tested between June and September 2022.
• Performance was evaluated in laboratory, field, and mobile testing settings.
• GeneXpert results were compared to an established in-house detection method.

Main Results:

• GeneXpert demonstrated 100% agreement in laboratory detection and 90% in field testing.
• High concordance in viral load was observed between methods in lab and field settings.
• Mobile testing showed lower agreement (62.5%) and encountered technical issues, but results were available in under an hour.

Conclusions:

• The GeneXpert system is a promising tool for rapid, deployable wastewater surveillance of SARS-CoV-2.
• The device offers a limit of detection of 12 cpml-1 with results in under an hour.
• Further validation and technical improvements are needed for consistent field and mobile application.