Integrating wastewater and randomised prevalence survey data for national COVID surveillance

Abstract

During the COVID-19 pandemic, studies in a number of countries have shown how wastewater can be used as an efficient surveillance tool to detect outbreaks at much lower cost than traditional prevalence surveys. However, all of these studies have been set in a specific city or region; none have attempted to embed wastewater in a country-level surveillance system. In the post-pandemic era, a likely scenario is that prevalence surveys will be run at a reduced scale; hence an affordable ongoing surveillance system will need to combine sparse prevalence data with non-traditional disease metrics such as wastewater measurements in order to estimate dis- ease progression in a cost-effective manner. Here, we use data collected during the pandemic to model the dynamic relationship between spatially granular wastewater viral load and disease prevalence. We then use this relationship to nowcast local disease prevalence under the scenario that (i) spatially granular wastewater data continue to be collected; (ii) direct measurements of prevalence are only available at a coarser spatial resolution, for example at national or regional scale. The model framework is disease-agnostic and could therefore be adapted to different diseases and incorporated into a multiplex surveillance system for early detection of emerging local outbreaks.

Mathematical assessment of wastewater-based epidemiology to predict SARS-CoV-2 cases and hospitalizations in Miami-Dade County

“…For example, the United States Centers for Disease Control (CDC) launched the National Wastewater Surveillance System (NWSS) in September of 2020 to "coordinate and build the nation's capacity to track the presence of SARS-CoV-2, the virus that causes COVID-19, in wastewater samples collected across the country" [9]. Some of the benefits of wastewater-based surveillance epidemiology includes the fact that it is a less invasive surveillance mechanism (unlike the use of mass testing or large scale genomic surveillance to detect disease activity in the community) and cost-effective (in comparison to the cost of testing kits, for instance) [10,11]. In addition to being a "leading indicator" or an "early warning signal" for disease presence or activity in a community, it can provide important insight into the presence of disease variants or their entry into community (by monitoring wastewater in airports or on airplanes) [17][18][19][20][21].…”

“…Wastewater-based surveillance epidemiology has numerous benefits. It, for instance, is a less invasive disease surveillance mechanism, in comparison to conducting mass testing to detect the level of spread of a pathogen in the community [10]. Furthermore, in the context of COVID-19, while a kit for rapid antigen tests can cost as little as 2 dollars to manufacture, bidding wars between health systems, state governments and employers can contribute to much higher prices [11].…”