New Wastewater Monitoring Reveals Rise of COVID-19 Variant and Hints at Hidden Illnesses
August 20, 2025
A Refined network of Wastewater monitoring, initially developed during the 2020 Coronavirus pandemic, is now offering unprecedented insights into the health of populations. Researchers are expanding its capabilities beyond COVID-19 to detect a range of pathogens and traces of pharmaceuticals and illicit drugs.
Tracking the Stratus Variant
Recent data indicates the increasing prevalence of the Stratus variant, a sub-lineage of Omicron. Sequencing analysis of wastewater from six Swiss treatment plants – Basel, Chur, Geneva, Laupen, Lugano, and Zurich – shows that Stratus has become the dominant strain in five of them as of mid-June. In Chur, the variant accounted for up to 99% of detected Coronavirus fragments, while Zurich and Lugano reported 75% and 80% respectively. This details is publicly available on an Eth Zurich bioinformatics dashboard.
Despite its growing presence, the World Health Association (WHO) currently assesses the Stratus variant – designated XFG – as not posing a meaningful threat, stating it does not cause more severe illness then other circulating variants.
Expanding Monitoring to Include Drugs
Before the pandemic, Swiss researchers collaborated with the University of Lausanne (unil) to monitor pharmaceutical and drug traces in wastewater. This work contributed significantly to the establishment of the European Union drug agency,Euda’s drug monitoring program,through standardized testing across multiple countries. Switzerland joined the European Monitoring Center for drugs and Drug Addiction (EMCDDA), the predecessor to Euda, in 2017, and now its data is integrated into annual European reports via the Euda data platform.
Since 2021, virus and pharmaceutical monitoring have largely run parallel, analyzing wastewater for SARS-CoV-2, Influenza A and B, RSV, and 15 pharmaceutical active ingredients, including those related to coughs, influenza, antibiotics, opioids, and antidepressants. Data accessible through dedicated platforms for viruses and pharmaceuticals.
New Insights from Combined Data
Combining these two monitoring programs is unlocking new analytical capabilities. Researchers anticipate a correlation between increased virus detection and corresponding increases in medication usage. A recent study published in Nature Water largely confirms this relationship. Though, analyses have also identified unexpected medication consumption patterns that could not be directly linked to previously detected pathogen waves.
These unexpected patterns suggest undiagnosed illnesses or evolving health trends within the population. Subsequent comparisons with hospital and general practitioner data have indicated the pharmaceutical peaks may be linked to widespread rhinovirus infections (the common cold) and pertussis bacteria (whooping cough).
| Pathogen/Substance | Monitoring Method | potential Indicator Of |
|---|---|---|
| SARS-CoV-2 (Stratus Variant) | Viral RNA sequencing | Emerging COVID-19 strains, pandemic trends |
| Influenza A/B | Viral RNA detection | Flu outbreaks, seasonal illness patterns |
| Antibiotics | Pharmaceutical residue analysis | Antibiotic resistance, bacterial infections |
| Opioids | Pharmaceutical residue analysis | Pain management trends, potential drug misuse |
Did You Know? Wastewater analysis can detect as few as one viral particle per liter of water, making it an incredibly sensitive surveillance tool.
A Proactive Approach To Public Health
According to Christian Stamm, Deputy Director of Eawag, the combined chemical and microbiological analysis of wastewater offers a unique chance to identify emerging health challenges and underlying societal stressors. He emphasized the need for interdisciplinary collaboration between chemical and microbiological experts.He also highlighted the importance of standardized sampling, storage, analysis, and data management for effective implementation of wastewater-based epidemiology in Switzerland.
Pro Tip: Regular monitoring allows for quicker responses to outbreaks and better allocation of public health resources.
the Future of Wastewater Surveillance
the use of wastewater surveillance is expanding globally, with countries increasingly recognizing its value in early warning systems for various health threats. Technological advancements, such as improved sensor technology and data analytics, are further enhancing the accuracy and speed of analysis.Moreover, the integration of data from multiple sources – including clinical data, social media trends, and environmental factors – promises a more comprehensive understanding of public health dynamics. While challenges remain, notably in ensuring data privacy and standardization across different regions, the potential for wastewater surveillance to transform public health practice is immense.
Frequently Asked Questions about Wastewater Monitoring
- What is wastewater monitoring? Wastewater monitoring involves analyzing sewage for the presence of viruses,bacteria,pharmaceuticals,and other substances to assess public health trends.
- How does wastewater monitoring detect COVID-19? The method detects viral RNA fragments shed by infected individuals in their waste.
- What are the limitations of wastewater monitoring? It provides population-level data but cannot identify individual cases and is affected by factors like rainfall and sewage flow.
- Is the data from wastewater monitoring reliable? When conducted with standardized methods and quality control,it offers a high degree of accuracy and sensitivity.
- Can wastewater monitoring detect new pathogens? Yes, the method can be adapted to identify emerging pathogens as research advances.
What role do you think wastewater monitoring should play in future public health strategies? Share your thoughts in the comments below!
