RALEIGH, N.C. (WNCN) – For the last two years, scientists across the state have checked wastewater for COVID-19. Now, North Carolina Department of Health and Human Services is using the same practice for the latest health threat.

NCDHHS confirms they started surveilling wastewater for monkeypox about two weeks ago.

“All 25 sites sampled were negative/below detection for monkeypox. It is unknown how many cases are needed in an area before detection is possible in wastewater,” NCDHHS said.

The department said sampling will continue through the coming weeks and months.

To detect COVID in wastewater, labs collect samples from two dozen water treatment plants across the state. The information from the collected wastewater acts as a crystal ball, predicting trends up to six days early.

The state currently has 38 monkeypox cases statewide.

When it comes to COVID, the samples allow the state to plan where they may need to increase testing or where to expect increased hospitalizations.

What the data cannot tell researchers is the number of people infected in a given community or how sick they are. Because what individuals flush all ends up at wastewater treatment plants, surveillance can’t tell exactly who is infected.

Wastewater continues to be a valuable tool in the COVID-19 pandemic. Last week’s coronavirus metrics showed the amount of COVID particles showing up in wastewater was up 55 percent from the previous week. That increase was also reflected in the case count with a slight increase in the number of new cases reported.

The state’s numbers from last week showed the state detected 25.7 million virus particles per person—the most since the week that ended June 1 but lower than the amount found during the omicron surge in January.