Researchers at Michigan State University say wastewater surveillance could become a valuable tool for tracking Michigan's ongoing cyclosporiasis outbreak, which has grown to more than 10,700 reported cases, the largest in the state's history.

Scientists in MSU's Water Quality and Environmental Microbiology Lab are adapting wastewater monitoring methods previously used to detect pathogens such as SARS-CoV-2, influenza, RSV and norovirus to identify Cyclospora cayetanensis, the parasite responsible for cyclosporiasis. The research aims to help public health officials identify outbreak hotspots, monitor disease trends and prioritize clinical testing and response efforts.

The research team is developing a detection method using droplet digital PCR (ddPCR) to identify trace amounts of the parasite's DNA in wastewater. Once validated, the approach could provide a community-wide view of infection trends without relying solely on clinical case reporting.

Researchers noted that as infected individuals shed the parasite, millions of Cyclospora oocysts may enter wastewater systems each day. While conventional wastewater treatment removes some oocysts, chlorination does not effectively inactivate the parasite. The researchers emphasized that wastewater monitoring is intended to complement, rather than replace, traditional public health investigations by helping identify areas where additional testing or interventions may be needed.

The effort builds on Michigan's existing wastewater surveillance infrastructure and highlights the expanding role of wastewater-based epidemiology in monitoring emerging public health threats.