COVID-19 Wastewater Monitoring Indicates High Viral Activity Nationwide, Midwest Leads Regions

Visit the CDC's online resource center for more information on the wastewater viral activity level and data calculation methods.

The United States is experiencing high levels of SARS-CoV-2 viral activity in wastewater, with the Midwest leading all regions, according to the latest national monitoring data. Wastewater surveillance, a critical early detection tool for community spread of COVID-19, reveals trends that could indicate rising infection risks even before symptoms appear or clinical testing increases.

Nationwide and Regional Trends

The national wastewater viral activity level for COVID-19 is high. Median viral activity levels across wastewater treatment plants provide a snapshot of SARS-CoV-2 prevalence in communities.

The Midwest currently reports the highest median viral activity level among all U.S. Census Bureau-defined regions. This level of monitoring highlights the increased risk of infection and underscores the importance of preventive measures.

How Wastewater Monitoring Works

Wastewater monitoring serves as an early warning system for viral spread. By detecting SARS-CoV-2 in sewage, health officials can identify infection trends within a community days or weeks before individuals seek medical care. This method also captures asymptomatic cases, which might otherwise go unnoticed.

Wastewater Viral Activity Levels Explained

The wastewater viral activity level measures the concentration of SARS-CoV-2 detected in wastewater, categorized as:

Minimal (Up to 1.5): Very low levels of the virus.
Low (1.5–3): Indicates low community spread.
Moderate (3–4.5): Higher but controlled virus presence.
High (4.5–8): Suggests significant viral circulation and infection risk.
Very High (Above 8): Alarming levels of community transmission.

National and regional data reflect median viral concentrations across treatment plants, offering a comprehensive view of infection potential.

Regional Breakdown

U.S. Census Bureau designations group regions:

West: States including California, Arizona, and Washington.
Midwest: States such as Illinois, Ohio, and Minnesota.
Northeast: States including New York, Pennsylvania, and Massachusetts.
South: States such as Texas, Florida, and Georgia.

Currently, the Midwest holds the highest activity level, followed by other regions showing varying degrees of viral presence.

Implications of High Wastewater Viral Activity

Elevated wastewater viral levels suggest an increased risk of COVID-19 infections, prompting public health officials to encourage protective measures. Early detection through wastewater data allows for timely interventions to mitigate spread, especially during high or very high viral activity periods.

Protecting Yourself Against Respiratory Viruses

In light of the high wastewater viral activity levels, individuals can reduce their risk by:

Wearing masks in crowded or indoor public spaces.
Staying up to date with COVID-19 vaccinations and boosters.
Practicing good hygiene, including frequent handwashing.
Monitoring community data for trends in viral activity.

Public Awareness and Action

Health officials urge communities to monitor wastewater data trends. Rising viral activity levels often precede surges in clinical cases. Individuals and policymakers can reduce the strain on healthcare systems and protect vulnerable populations by acting early.

The Centers for Disease Control and Prevention (CDC) emphasizes the importance of wastewater monitoring as a reliable, cost-effective tool for pandemic management. As COVID-19 evolves, wastewater surveillance remains a cornerstone of public health response.

Visit the CDC’s online resource center for more information on the wastewater viral activity level and data calculation methods.