Community incidence patterns drive the risk of SARS-CoV-2 outbreaks and alter intervention impacts in a high-risk institutional setting

Nursing home wastewater surveillance for early warning of SARS-CoV-2-positive occupants-Insights from a pilot project at 8 facilities

BACKGROUND

Wastewater surveillance for SARS-CoV-2 has been used widely in the United States for indication of community incidence during the COVID-19 pandemic, but less is known about the feasibility of its use on a building level in nursing homes to provide early warning and prevent transmission.

METHODS

A pilot study was conducted at 8 Department of Veterans Affairs nursing homes across the United States to examine operational feasibility. Wastewater from the participating facilities was sampled daily during the week for 6 months (January 11, 2021-July 2, 2021) and analyzed for SARS-CoV-2 genetic material. Wastewater results were compared to new SARS-CoV-2 infections in nursing home residents and employees to determine if wastewater surveillance could provide early warning of a COVID-19-positive occupant.

RESULTS

All 8 nursing homes had wastewater samples positive for SARS-CoV-2 and COVID-19-positive occupants. The sensitivity of wastewater surveillance for early warning of COVID-19-positive residents was 60% (3/5) and for COVID-19-positive employees was 46% (13/28).

CONCLUSIONS

Wastewater surveillance may provide additional information for reinforcing infection control practices and lead to preventing transmission in a setting with high-risk residents. The low sensitivity for early warning in this real-world pilot highlights limitations and insights for applicability in buildings.