Medicines found in wastewater may signal Covid spread

Measuring the concentrations of medicines in wastewater could add another layer to disease-monitoring efforts and help curb spread of Covid-19, suggests a study.

In a pilot project exploring ways to monitor Covid-19, University at Buffalo scientists hunted for pharmaceuticals and viral RNA simultaneously in wastewater in Western New York.

"Wastewater-based disease surveillance is being done worldwide through monitoring of viral RNA," said lead scientist Diana Aga, Professor of Chemistry in the UB College of Arts and Sciences.

"The potential of complementing existing efforts with detection of pharmaceuticals is exciting. There are a lot of opportunities here, though more research is needed," she added.

One interesting discovery in the new study, published in the journal Environmental Science & Technology Letters, involves acetaminophen -- a pain reliever and fever reducer that serves as an active ingredient in over-the-counter medicines such as Tylenol, Theraflu, and other brands.

At all four wastewater treatment plants included in the project, the research found that acetaminophen concentrations in wastewater spiked before other measures of Covid-19 in the community in early 2021, including concentrations of Covid-19 viral RNA in wastewater and the estimated number of confirmed Covid-19 cases.

The spike in viral RNA, in turn, preceded the spike in the estimated number of confirmed cases of Covid-19 by about a week, scientists say.

"Our biggest finding is that there's a huge increase in the concentration of acetaminophen, which is used in over-the-counter drugs, that predates the peak of viral RNA in wastewater and the peak in clinical detections in our area during the study period," Aga said.

"This was very interesting, as it suggests that detection of pharmaceuticals could act as an early warning of a potential disease outbreak in a community," Aga said.

Wastewater data is becoming a crucial part of monitoring Covid-19 as home testing has become more popular, leading to many positive cases going unreported.

In addition to identifying the spikes in acetaminophen, the study found residues of prescription medications associated with the pandemic in wastewater, including drugs whose emergency use authorisation for treating Covid-19 has been revoked by the US Food and Drug Administration.