Wastewater COVID-19 Surveillance to Prevent Outbreaks

Although non-pharmaceutical interventions, such as face coverings, hand hygiene, and physical distancing, helped prevent the spread of COVID-19 during the pandemic, outbreaks continued to occur. Preventing COVID-19 spread in congregate settings, such as shelters and correctional facilities, was particularly challenging, because their populations live in close proximity, often have significant co-morbidities, and did not have equal access to COVID-19 testing, vaccination, and medical treatment resources. In addition, health and exposure screening strategies were not highly effective in congregate settings due to asymptomatic and pre-symptomatic viral spread. Due to these and other factors, many congregate settings nationwide experienced severe COVID-19 outbreaks, with considerable morbidity and mortality. To identify COVID-19 outbreaks at congregate settings at the earliest stage possible, the New Mexico Environment Department asked ERG to design and implement a COVID-19 wastewater surveillance program that would provide an early sentinel of spreading disease.

ERG worked with NMED to identify appropriate sampling points at each facility, develop sampling protocols, collect and analyze samples, and evaluate and present results to inform policy decisions. Twice weekly for a year, ERG helped NMED collect and analyze sewage samples at participating facilities and provided health-related interpretations of observed data trends. This effort avoided at least one outbreak, when sampling detected COVID-19 particles in a facility’s wastewater, which prompted nasal swab testing of all clients and staff. The testing identified an asymptomatic COVID-19 positive person who was immediately isolated from others. The virus was not present in later wastewater samples from the facility, indicating that the wastewater detection effort prevented a potential COVID-19 outbreak.