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



Wastewater surveillance may represent a complementary approach to measure the presence and even prevalence of infectious diseases when the capacity for clinical testing is limited. Moreover, aggregate, population-wide data can help inform modeling efforts. We tested wastewater collected at a major urban treatment facility in Massachusetts and found the presence of SARS-CoV-2 at high titers in the period from March 18 – 25 using RT-qPCR. We then confirmed the identity of the PCR product by direct DNA sequencing. Viral titers observed were significantly higher than expected based on clinically confirmed cases in Massachusetts as of March 25. The reason for the discrepancy is not yet clear, however, and until further experiments are complete, these data do not necessarily indicate that clinical estimates are incorrect. Our approach is scalable and may be useful in modeling the SARS-CoV-2 pandemic and future outbreaks.

Competing Interest Statement

MM and NG are cofounders of Biobot Analytics. EJA is advisor to Biobot. NE and CD are employees at Biobot. All these authors hold shares in the company.

Funding Statement

WPH was supported by the National Institute of General Medical Sciences. This work was supported by the Center for Microbiome Informatics and Therapeutics and Intra-CREATE Thematic Grant (Cities) grant NRF2019-THE001-0003a to JT and EJA.

Author Declarations

All relevant ethical guidelines have been followed; any necessary IRB and/or ethics committee approvals have been obtained and details of the IRB/oversight body are included in the manuscript.


All necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived.


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Data Availability

Detailed methods available upon request.

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