(1397-B) Wastewater surveillance of infectious disease using an integrated handheld device
Monday, February 5, 2024
2:00 PM – 3:00 PM EST
Location: Exhibit Halls AB
Abstract: Wastewater-based epidemiology (WBE) tracks the prevalence of pathogens in a community via wastewater analysis. During the COVID-19 pandemic, WBE has provided valuable information on infection rates and concentration of SARS-CoV-2 and served as an early warning system. Current wastewater surveillance platforms are based on delivering samples to a centralized lab with an extensive infrastructure, which is not available in many parts of the world. Another challenge in WBE is the complexity of sample processing steps, which are time-consuming and expensive. As WBE increases in scope (beyond SARS-CoV-2) and scale (beyond developed regions), there is a need to make WBE processes simpler, cheaper, and faster. Our vision entails the development of a point-of-use device for WBE, which has the potential to revolutionize WBE in the same way that point-of-care (POC) testing has transformed diagnostics. This technology is most impactful in rural and low-resource settings, where environmental surveillance can lead to the democratization of public health tools and offer more equitable healthcare. Moreover, with several (re)emerging pathogens including measles and polio on the horizon, such devices can help in timely public health responses. In this study, we have developed an integrated easy-to-use and inexpensive concentration-extraction-identification device (CEID) to detect low-prevalence pathogens (e.g., SARS-CoV-2 in wastewater). The CEID functions by employing an extraction process that makes use of the interface between aqueous and organic liquids in microchannels. This approach simplifies the process by replacing multiple washing steps with a single passage through an immiscible fluid barrier. The CEID is fabricated by laser cutting and engraving 3.7mm thick PMMA sheets. The resultant chambers on the chip are filled with appropriate buffers. Paramagnetic particles (PMPs) bind to nucleic acids in the lysed wastewater sample, and a magnet is used to pull them through the CEID device, resulting in the washing of PMPs. The PMPs are then released in the elution buffer which also contains the reagents for colorimetric loop-mediated isothermal amplification (LAMP). The CEID is then placed on a heater at 65 C for 30 minutes. In the presence of the target (e.g., a specific viral RNA sequence), the LAMP reaction color changes from pink to yellow. The CEID is optimized and evaluated using wastewater samples spiked with heat-inactivated SARS-CoV-2 and compared with an established method. The CEID limit of detection for measuring SARS-CoV-2 in wastewater is about 20 copies per mL of sample. Our device is a fast ( < 35 mins) and inexpensive (~$12/sample) detection method for low-prevalence pathogens in environmental samples. Also, it eliminates the need for complex equipment and specialized personnel and minimizes the liquid handling steps. While our current technology allows for the identification of a pathogen in a wastewater matrix, our next goal is to be able to quantify the concentration.