Opinion: Wastewater analysis can be a powerful public health tool-if it's done sensibly.

Abstract

The coronavirus disease 2019 (COVID-19) pandemic sparked an explosion of interest in wastewater-based epidemiology (WBE; also known as wastewater monitoring or wastewater surveillance). Much has been said, in the scientific literature and popular press alike, about the public health value of tracking severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in wastewater. Emergence and spread of the omicron variant has recently pushed WBE for COVID-19 management back into headlines. Unfortunately, coverage of the potential of WBE is rarely balanced by a practical discussion of limitations and tradeoffs, especially when it comes to issues beyond technical challenges encountered in the lab. Sometimes wastewater-based epidemiology makes sense as a way to monitor disease outbreaks and other public health threats, and sometimes constraints argue for spending scarce resources elsewhere. We grapple with such issues frequently while managing a WBE program for Healthy Davis Together (HDT), a multi-pronged pandemic-response initiative in Davis, CA. Since launching in September 2020, the program has grown to include in-house analysis of wastewater collected on a weekly, triweekly, or daily basis from 70 sites distributed across the City of Davis and the University of California, Davis (UC Davis) campus sewer systems and from the influent of their wastewater treatment plants. We are glad that our wastewater data are informing local COVID-19 mitigation efforts. Results from wastewater collected from UC Davis dorm outflows are supporting the safe return of students to campus; results from wastewater collected from neighborhoods and broader city areas are helping public officials understand spatial changes in COVID-19 trends and react accordingly. At the same time, launching and running a WBE campaign requires significant investments of time, money, labor, and expertise. Given that much information gleaned from wastewater is not directly actionable, and/or duplicates information from other sources, it is prudent to consider when these investments are worthwhile. … [↵][1]1To whom correspondence may be addressed. Email: hbischel{at}ucdavis.edu. [1]: #xref-corresp-1-1