Recent trial programs looking at the efficacy of testing wastewater to detect COVID-19 outbreaks have yielded important insights about how this method of testing can be used to improve public health, including providing an early indicator of infection that can be used to trigger advisories and recommendations.

A webinar titled How to Bring COVID-19 Wastewater Monitoring into the Field was hosted by 120Water, and included experts from 120Water, the Environmental Protection Agency (EPA), The Water Research Foundation and the Ohio Department of Health.

Key findings of the discussion include:

• Wastewater surveillance has been shown to be effective in identifying the presence of SARS-CoV-2 RNA, which is shed by people infected with COVID-19, and eventually may be able to provide early detection for this and other illnesses to support health decision making.

The WRF has six trials underway, and one trial completed that looked at the best methods to assess the COVID-19 genetic signal in wastewater. “One of the aims in doing this research is to go from a point where we’re not only detecting and informing in a reactive way, but able to do early detection through wastewater surveillance,” says Christobel Ferguson, chief innovation officer at WRF. “Further research is necessary to establish a definitive correlation between the clinical status of communities and the genetic signal for SARS-CoV-2 in wastewater. Yet, even in the absence of that information, wastewater testing is able to help inform health actions.”

• Wastewater testing for COVID-19 is able to capture unbiased information about community infection, even in marginalized communities that may not have access to tests.

“Empirical evidence shows us that certain communities are more likely to contract and die of COVID-19, and wastewater testing is valuable because it can be adapted to get outbreak risks at different scales — from one building all the way to an entire state,” says Erica Walker, director of environmental policy and programs at 120Water, which is a partner with the State of Indiana in its COVID-19 wastewater trial underway at 60 sample sites throughout the state. “Small communities without robust testing strategies may be able to use wastewater for sentinel testing.”

• Rainfall has been shown to have a diluting effect on SARS-CoV-2 in wastewater, which reduces detection.

A study conducted by the EPA for the Ohio Coronavirus Wastewater Network shows an inverse relationship between the amount of rain and the level of virus concentrated in wastewater. “We are working on developing models that account for factors such as dilution that influence virus detection and are important for describing the relationship between case data and the presence of SARS-CoV-2 in wastewater,” says Nichole Brinkman, a microbiologist with the EPA.

• Wastewater testing can prepare communities earlier to combat outbreaks.

The Ohio Department of Health is leveraging the state’s Coronavirus Wastewater Network to notify local health districts and utilities about trends showing an increase in SARS-CoV-2 viral load in wastewater along with a toolkit to help these areas combat the virus through pop-up testing, additional PPE, communications and hospital mobilization. “Our focus is on pinpointing trends that imply a leading indicator of infection,” says Rebecca Fugitt, assistant chief of the Bureau of Environmental Health and Radiation Protection with the Ohio Department of Health. “Our goal is to be able to better understand factors that affect disease spread, especially in communities that are disproportionately affected.”

A second webinar discussion, How to Bring COVID-19 Wastewater Monitoring to your Community, is planned for Nov. 17, at 1 p.m. EST. To register, go to https://120water.com/webinars/part-2-covid-wastewater-monitoring/.