SARS-CoV-2 titers in wastewater are higher than expected from clinically confirmed cases

Fuqing Wu; Amy Xiao; Jianbo Zhang; Xiaoqiong Gu; Wei Lin Lee; Kathryn Kauffman; William Hanage; Mariana Matus; Newsha Ghaeli; Noriko Endo; Claire Duvallet; Katya Moniz; Timothy Erickson; Peter Chai; Janelle Thompson; Eric Alm

Introduction. Improved understanding of the presence and prevalence of SARS-CoV-2 at a population level can help government and hospital officials implement appropriate policies to mitigate the exponential spread of COVID-19, and diminish the future strain on healthcare facilities. Despite pandemic spread of SARS-CoV-2 worldwide, broad access to testing in the United States (US) has thus far been severely limited. While it is impractical to test every US resident for SARS-CoV-2, the virus has been found in the stool of confirmed COVID-19 patients (1), making it a promising candidate for wastewater-based epidemiology (WBE). WBE can help detect the presence of pathogens across municipalities and estimate population prevalence without individual testing, and inform public health officials of the efficacy of interventions. The closely related virus SARS-CoV was detected in wastewater from Chinese hospitals during the 2002-2003 SARS pandemic (2) , and WBE has been used for the early detection and direct mitigation of disease outbreaks in Israel, Egypt and Sweden (3) (4) (5) (6) (7) . We have previously used this technique to measure and map the use of pharmaceuticals across residential communities (8) . Here, we describe an analytical technique to extract and detect genetic material from SARS-CoV-2 using wastewater collected at a treatment facility.