The Center for Disease Control and Prevention (CDC), together with the nation's Department of Health and Human Services, will start working with state, local, and tribal health departments to test sewage systems for coronavirus disease 2019 (COVID-19).

This effort is called the National Wastewater Surveillance System (NWSS), according to the CDC. This initiative aims to find traces of coronavirus in the sewage system that can contain fecal waste of people infected with COVID-19. 

The wastewater testing is not intended to replace clinical testing. However, it is believed that it can help communities where COVID-19 tests are unavailable.

Sewage systems testing could reach up to 80 percent of U.S. households connected to a municipal sewage system.

Sewage systems testing can also indicate a worsening outbreak depending on the level of virus found in the sewage systems.

The CDC said coronavirus can be shed in the feces of infected people whether they are symptomatic or asymptomatic. The wastewater surveillance would then allow scientists to collect data on both types of infection.

Sewage Systems

Sewage systems testing has been used to trace other diseases such as polio. It can also be used to see the prevalence of opioid use in some U.S. communities.

Dr. Ashish Jha, director of the Harvard Global Health Institute, is among some public health experts that said sewage testing for COVID-19 is a cost-effective strategy to track the coronavirus. It can also prevent any further community outbreaks.

The CDC is not yet taking any samples from any sewage systems. It is still searching for local partners to test and report the data agency's NWSS portal. 

Some counties have already conducted sewage systems testing to track COVID-19.

Sewage Systems Testing

Researchers at the University of Minnesota Medical School's Duluth Campus observed the presence of COVID-19 in sewage across Minnesota.

They found levels of viral particles in the wastewater that reflects increasing cases across the state. It has also given them early signs of possible COVID-19 outbreak.

In June, researchers discovered that four bars in Mankato and Minneapolis showed signs of increasing cases there. It was even before the state-linked those four areas to the sudden increase.

"We kind of started seeing things that indicated that something was going on down there before that story broke," Medical school assistant professor and researcher, Glenn Simmons Jr. said in a report.

Researchers claimed that infected people likely shed the virus in stools before showing symptoms. Thus, it could help identify how many people in an area actually have coronavirus based on wastewater testing. However, Simmons said this will still require more work.

"We're still working really, really hard to see if we can get this to the point where we can interpret how many people these numbers are representing. It's not as clear-cut as we had hoped," he noted.

The research also showed that there could also be complicated factors such as rainwater diluting the sample or the mass movement of people. 

Researchers are taking wastewater samples from 22 sites across Minnesota, with another eight added soon. 

Simmons said they are still looking to cover as much of the state as possible. He noted that they would like to, at least, double the number of sites that they are testing.

Countries like Finland, Germany, and the Netherlands have already started testing wastewater. 

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