Covid-19 Monitoring Through Wastewater Testing #

New Covid-19 infections are no longer tracked or reported as closely as they were during the public health emergency. Instead, officials now focus on testing the contents of wastewater to keep tabs on the virus.

To identify virus levels and larger trends, a large network of sampling sites at wastewater treatment facilities across the country is utilized. The monitoring network covers about 43% of the population.

The process doesn’t precisely count the numbers of cases, and readings can vary based on sewage flows at a particular location or the characteristics of a given variant at a point in time. However, it provides an early warning about viral spread.

Viral levels vary over time and by location. Trends are monitored by state, with rankings in ascending order by the severity of the viral activity during the most recent testing period.

Samples are taken from sampling sites around the United States that meet criteria to sufficiently anonymize the data. The sampling allows for results from a large snapshot of the population, not just individuals who are in the health care system. Wastewater data also helps track new Covid variants and other infectious diseases, such as RSV and mpox.

The percentage change in viral levels at each location where data was collected during a 15-day period is reported, with some densely populated states having more testing locations than others. Some sites saw an increase in activity, while others experienced a decrease.

This wastewater monitoring approach provides a broader perspective on viral spread in communities and serves as a valuable tool for public health officials in tracking and responding to Covid-19 and other infectious diseases.