SARS-CoV-2 Detection from the Built Environment and Wastewater and Its Use for Hospital Surveillance

Hinz, A.; Xing, L. Y.; Doukhanine, E.; Hug, L. A.; Kassen, R.; Ormeci, B.; Kibbee, R. J.; Wong, A.; MacFadden, D.; Nott, C.

Background. SARS-CoV-2 causes significant morbidity and mortality in health care settings. Our understanding of the distribution of this virus in the built healthcare environment and wastewater, and relationship to disease burden, is limited. Methods. We performed a prospective multi-center study of environmental sampling of SARS-CoV-2 from hospital surfaces and wastewater and evaluated their relationships with regional and hospital COVID-19 burden. We developed and validated a qPCR-based approach to surface sampling, and swab samples were collected weekly from different locations and surfaces across two tertiary care hospital campuses for a 10-week period during the pandemic, along with wastewater samples. Results. Over a 10-week period, 963 swab samples were collected and analyzed. We found 61 (6%) of swabs were positive for SARS-CoV-2, with the majority of these (n=51) originating from floor samples. Wards that actively managed patients with COVID-19 had the highest frequency of positive samples (p<0.01). Detection frequency in built environment swabs was significantly associated with active cases in the hospital throughout the study (p<0.025). Wastewater viral signal changes appeared to predate change in case burden. Conclusions. Environment sampling for SARS-CoV-2, in particular from floors, may offer a unique and resolved approach to surveillance of COVID-19.