Detection of SARS-CoV-2 in Wastewater at Residential College, Maine, USA, August-November 2020

Abstract

We used wastewater surveillance to identify 2 coronavirus disease outbreaks at a college in Maine, USA. Cumulative increases of >1 log₁₀ severe acute respiratory syndrome coronavirus 2 RNA in consecutive 24-hour composite samples preceded the outbreaks. For 76% of cases, RNA was identified in grab samples from residence halls <7 days before case discovery.

Keywords: 2019 novel coronavirus disease; COVID-19; Maine; SARS-CoV-2; United States; colleges; coronavirus disease; coronaviruses; nucleic acid detection; residential colleges; respiratory infections; severe acute respiratory syndrome coronavirus 2; students; surveillance; viruses; wastewater; wastewater surveillance; zoonoses.

Figure

Detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA in wastewater samples at a residential college, Maine, USA, August–November 2020. A) Grab samples from 6 residence halls (i.e., A–F). B) 24-hour composite samples from 2 lift stations: L1 for halls E–F and L3 for halls A–D. Dashed lines indicate theoretical limit of detection; dotted lines indicate limit of quantification. These limits were dependent on flow rate (B only) and population served for each sample. Data points below dashed lines indicate undetected concentrations of SARS-CoV-2 RNA and are recorded at one-half the limit of quantification (5). Data points between dashed and dotted lines indicates detectable but nonquantifiable concentrations of SARS-CoV-2 RNA and are recorded at one half the limit of quantification. C) Daily positivity rate of COVID-19 tests. The number above the bar indicates the number of positive cases. Positive results were typically received within 24 hours after administration of the diagnostic test. D) Total COVID-19 diagnostic tests, including surveillance and nonsurveillance tests. Letter and symbol indicate resident hall of affected student. Shaded areas indicate the days during which the college declared an active outbreak. COVID-19, coronavirus disease.