Wastewater and surface monitoring to detect COVID-19 in elementary school settings: The Safer at School Early Alert project

Abstract

Schools are high-risk settings for SARS-CoV-2 transmission, but necessary for children's educational and social-emotional wellbeing. While wastewater monitoring has been implemented to mitigate outbreak risk in universities and residential settings, its effectiveness in community K-12 sites is unknown. We implemented a wastewater and surface monitoring system to detect SARS-CoV-2 in nine elementary schools in San Diego County. Ninety-three percent of identified cases were associated with either a positive wastewater or surface sample; 67% were associated with a positive wastewater sample, and 40% were associated with a positive surface sample. The techniques we utilized allowed for near-complete genomic sequencing of wastewater and surface samples. Passive environmental surveillance can complement approaches that require individual consent, particularly in communities with limited access and/or high rates of testing hesitancy.

Wastewater sequencing uncovers early, cryptic SARS-CoV-2 variant transmission

“…To identify epidemiological transmission links and monitor lineages in the population, we sequenced all SARS-CoV-2 positive clinical and wastewater samples from campus using a miniaturized tiled-amplicon sequencing approach. During this period of this study, we collected and analyzed 21,383 wastewater samples: 19,944 wastewater samples from the UCSD campus, and, for comparison, 1,439 wastewater samples from the greater San Diego area, including the Point Loma wastewater treatment plant (the primary wastewater treatment plant for the county with a catchment size of 2.3 million people) and 17 public schools spanning four San Diego school districts 15 . We compared sequencing of 600 campus wastewater samples to 759 genomes obtained from campus clinical swabs (46.2% of all positive tests on campus), all processed by the CALM and EXCITE CLIA labs at UCSD.…”

Sentinel Cards Provide Practical SARS-CoV-2 Monitoring in School Settings

“…For this study we used three viral loads: "high" (4 x 10 4 ), "medium" (1 x 10 4 ), and "low" (2.5 x 10 3 ) dilutions of SARS-CoV-2 viral genomic equivalents, as measured by droplet digital PCR. These concentrations were chosen to bracket the ranges we typically observed in classrooms during SASEA [9]. We used two different transport media: SDS (0.5% w/v sodium dodecyl sulfate (SDS), Acros Organics, 230420025), which we have To continue benchmarking proven environmental pipelines [7,9,11] and to account for potential interactions, we used a factorial study design covering two swabbing media (SDS, VTM), three cleaning solutions (BZK wipes, wet wipes, RNase Away) and three viral spike-in concentrations (High, Medium, Low).…”

“…These concentrations were chosen to bracket the ranges we typically observed in classrooms during SASEA [9]. We used two different transport media: SDS (0.5% w/v sodium dodecyl sulfate (SDS), Acros Organics, 230420025), which we have To continue benchmarking proven environmental pipelines [7,9,11] and to account for potential interactions, we used a factorial study design covering two swabbing media (SDS, VTM), three cleaning solutions (BZK wipes, wet wipes, RNase Away) and three viral spike-in concentrations (High, Medium, Low). Each condition was performed in triplicate for a total of 54 cards.…”

“…To continue benchmarking proven environmental pipelines [7, 9, 11] and to account for potential interactions, we used a factorial study design covering two swabbing media (SDS, VTM), three cleaning solutions (BZK wipes, wet wipes, RNase Away) and three viral spike-in concentrations (High, Medium, Low). Each condition was performed in triplicate for a total of 54 cards.…”

“…Wastewater and environmental monitoring strategies have been developed [6][7][8] and implemented [9] as a means of circumventing clinical swabs. We have already demonstrated that viral signals from COVID-19 patients in indoor environments commonly accumulate on high-touch surfaces and the floors in front of features with high interaction times [8].…”