Development of Wastewater Pooled Surveillance of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) from Congregate Living Settings

Abstract

Wastewater-based monitoring for SARS-CoV-2 at individual building-level could be an efficient, passive means of early detection of new cases in congregate living settings, but this approach has not been validated. Preliminary samples were collected from a hospital and a local municipal wastewater treatment plant. Molecular diagnostic methods were compared side-by-side to assess feasibility, performance and sensitivity. Refined sample collection and processing protocols were then used to monitor two occupied dormitory complexes (n = 105 and 66) over eight weeks. Wastewater results were validated using known case counts from external clinical testing of building occupants. Results confirm that ultracentrifugation from a 24 hour composite collection had a sensitivity of 96.2% and a specificity of 100%. However, the method could not distinguish new infectious cases from persistent convalescent shedding of SARS-CoV-2 RNA. If the detection of convalescent shedding is considered a false positive, then the sensitivity is 100% and specificity drops to 45%. It was determined that the proposed approach constitutes a highly sensitive wastewater surveillance method for detecting SARS-CoV-2, but it could not distinguish new infectious cases from persistent convalescent shedding. Future work must focus on approaches to distinguish new infections from convalescent shedding to fully realize the potential of building wastewater as a surveillance tool for congregate living. Importance Some of the most severe outbreaks of COVID-19 have taken place in places where persons live together, such as a nursing homes. Wastewater testing from individual buildings could be used for frequent pooled surveillance of virus from all occupants, including those who are contagious with or without symptoms. This work provides a sensitive practical method for detecting infected individuals, as validated in two building complexes housing occupants who underwent frequent clinical testing performed by external entities. Although this sensitive method could be deployed now for pooled surveillance as an early warning system to limit outbreaks, the study shows that the approach will require further refinement to differentiate between contagious newly infected individuals from persons who have persistent viral fragments shedding in their stool outside the contagious period.

Building-Level Wastewater Monitoring for COVID-19 Using Tampon Swabs and RT-LAMP for Rapid SARS-Cov-2 RNA Detection

“…The PPV we observed was much lower than the 82% reported during another study leveraging PEG precipitation and RT-qPCR, but the NPV we observed (80% versus 88.9%) was comparable (Betancourt et al, 2021). The specificity of the tampon swab and RT-LAMP method for COVID-19 cases was 80%, which is better than the 52% specificity reported for an ultracentrifugation and RT-qPCR method that did not distinguish new infections from convalescent (Colosi et al, 2021). Thus, the tampon swab and RT-LAMP approach may offer a specificity and NPV comparable to more sophisticated monitoring methods.…”

High-Frequency, High-Throughput Quantification of SARS-CoV-2 RNA in Wastewater Settled Solids at Eight Publicly Owned Treatment Works in Northern California Shows Strong Association with COVID-19 Incidence

“…Numerous independent COVID-19 WBE efforts have covered monitoring at a range of scales, from the building level to country-wide implementation ( 7 , 9 , 10 ). The methods employed have also varied, with the vast majority focusing on the liquid fraction of municipal wastewater.…”

A State-of-the-Art Scoping Review on SARS-CoV-2 in Sewage Focusing on the Potential of Wastewater Surveillance for the Monitoring of the COVID-19 Pandemic

“…Twenty-five studies reported either the detection of SARS-CoV-2 in the environment before the identification of clinical cases, or a rise in SARS-CoV-2 concentrations in the environment before these trends became visible in the numbers of cases or hospitalizations (Agrawal et al, 2021a ; Ahmed et al, 2021a ; Betancourt et al, 2021 ; Chavarria-Miró et al, 2021 ; Colosi et al, 2021 ; D'Aoust et al, 2021b ; Davó et al, 2021 ; Fongaro et al, 2021 ; Gibas et al, 2021 ; Gonçalves et al, 2021 ; Hata et al, 2021 ; Karthikeyan et al, 2021 ; Kumar et al, 2021 ; La Rosa et al, 2020 , 2021a ; Medema et al, 2020 ; Peccia et al, 2020 ; Prado et al, 2020 , 2021 ; Randazzo et al, 2020a , 2020b ; Saguti et al, 2021 ; Trottier et al, 2020 ; Wilder et al, 2021 ; Wurtzer et al, 2020 ). Occurrence of SARS-CoV-2 RNA in wastewater where no COVID-19 cases had been reported before.…”