Better Targeted COVID-19 Disease Management Through Wastewaters Monitoring

Re-opening the economy requires an unprecedented scaling of our capacity to test, track, and treat COVID-19 infections, which are already straining medical supply chains. To allocate scarce medical resources efficiently, we need data to identify which neighborhoods will need more test kits ahead of the onset of symptoms. With the support of the AXA Research Fund, Dr. Mari Winkler, from the University of Washington in the US, intends to address this challenge by monitoring wastewater pumping stations to detect COVID-19 in communities ahead of individual testing. Detection of COVID-19 at wastewater treatment plants has been shown to detect increases ahead of individual testing in the population. However, measurements at the treatment plant might be skewed by dilution and the degradation of the virus as it takes longer to reach the treatment plant. Additionally, the low geographical resolution prevents neighborhood-level monitoring to inform directed individual testing campaigns. To bridge these gaps, Dr. Mari Winkler plans to test for the prevalence of the virus at different levels of sampling, i.e. moving from facility wastewater samples to pump stations at different levels in the sewer network, in low-income, high-income, and student housing neighborhoods. Additionally, the researcher will use individual testing data to build a correlation between the prevalence of COVID-19 in neighborhoods and the quantity of SARS-CoV-2 in wastewater, with consideration for the rate of virus degradation in the sewers, the dilution rate in the sewers, and population density.

Dr. Mari Winkler seeks to improve mapping of the types of communities that are more likely to be infected by the virus. Monitoring wastewater allows us to “understand social disparities, enabling comparison of neighborhoods with varying demographics and access to testing,” according to the researcher. The project focuses on Seattle, located in Washington state’s most populous county (King County), which was the first city in the US impacted by COVID-19. More specifically, testing wastewater on facility level provides health information on populations that often lack formal access to individual testing. Dr. Mari Winkler is focusing on vulnerable populations like essential workers and homeless people “with no or poor healthcare”, deprived of legal status, and often living in “crowded housing facilities”. Tracking the virus at the facility level will provide health information on populations that are usually difficult to access. The study will combine results from different wastewater facilities to track the spread of the virus at the regional level.

Pump station monitoring is a valuable tool on multiple fronts in the effort to mitigate COVID-19. By gathering data at the neighborhood level, it enables the identification of hotspots for more efficient vaccination trials. This method also offers the dual advantage of being both “cheaper than individual testing” and “anonymous”. According to the researcher, using wastewater as a detection tool is a “first start from and beyond the Coronavirus,” as it can be used by public authorities for other diseases in the future. On the longer term, pump station monitoring could be adopted as a low-cost tool to inform targeted allocation of testing and vaccination resources and guide the timetable for lifting costly social isolation policies.