Wastewater monitoring of SARS-CoV-2 RNA at K-12 schools: comparison to pooled clinical testing data

Abstract

Background Wastewater measurements of SARS-CoV-2 RNA have been extensively used to supplement clinical data on COVID-19. Most examples in the literature that describe wastewater monitoring for SARS-CoV-2 RNA use samples from wastewater treatment plants and individual buildings that serve as the primary residence of community members. However, wastewater surveillance can be an attractive supplement to clinical testing in K-12 schools where individuals only spend a portion of their time but interact with others in close proximity, increasing risk of potential transmission of disease. Methods Wastewater samples were collected from two K-12 schools in California and divided into solid and liquid fractions to be processed for detection of SARS-CoV-2. The resulting detection rate in each wastewater fraction was compared to each other and the detection rate in pooled clinical specimens. Results Most wastewater samples were positive for SARS-CoV-2 RNA when clinical testing was positive (75% for solid samples and 100% for liquid samples). Wastewater samples continued to test positive for SARS-CoV-2 RNA when clinical testing was negative or in absence of clinical testing (83% for both solid and liquid samples), indicating presence of infected individuals in the schools. Wastewater solids had a higher concentration of SARS-CoV-2 than wastewater liquids on an equivalent mass basis by three orders of magnitude.

Solid–liquid partitioning of dengue, West Nile, Zika, hepatitis A, influenza A, and SARS-CoV-2 viruses in wastewater from across the USA

“…While several studies have examined the partition of SARS-CoV-2 RNA 38,[43][44][45] in wastewater, only two studies have examined the partition of influenza A RNA. 7,46 The fate and removal of enteric viruses, such as hepatitis A, has also been extensively studied in wastewater treatment plants, however, partitioning coefficients are not often reported.…”

Adsorption of Respiratory Syncytial Virus, Rhinovirus, SARS-CoV-2, and F+ Bacteriophage MS2 RNA onto Wastewater Solids from Raw Wastewater

“…Our results are consistent with previously reported partition/distribution coefficients for viral genetic markers in wastewater. For example, Li and co-workers 31 evaluated the distribution of endogenous SARS-CoV-2 RNA (N1, N2, and E genes) in wastewater samples and found higher concentrations of SARS-CoV-2 RNA in solids compared to the liquid fraction; K d (reported in their paper as the solid–liquid concentration ratio) ranged from 4000–20,000 mL·g –1 . Kim et al 31 also studied the distribution of endogenous SARS-CoV-2 RNA (S and N genes) in wastewater samples from two K-12 schools and observed similar results; viral RNA concentrations were higher in solids by three orders of magnitude, and K d (reported in their paper as the concentration ratio in solid to liquid samples) were 8600 and 16,000 mL·g –1 for SARS-CoV-2N and S genes, respectively.…”

“…For example, Li and co-workers 31 evaluated the distribution of endogenous SARS-CoV-2 RNA (N1, N2, and E genes) in wastewater samples and found higher concentrations of SARS-CoV-2 RNA in solids compared to the liquid fraction; K d (reported in their paper as the solid–liquid concentration ratio) ranged from 4000–20,000 mL·g –1 . Kim et al 31 also studied the distribution of endogenous SARS-CoV-2 RNA (S and N genes) in wastewater samples from two K-12 schools and observed similar results; viral RNA concentrations were higher in solids by three orders of magnitude, and K d (reported in their paper as the concentration ratio in solid to liquid samples) were 8600 and 16,000 mL·g –1 for SARS-CoV-2N and S genes, respectively. We observed similar partitioning behavior for SARS-CoV-2, RSV, RV, and MS2 RNA in our study; except for SARS-CoV-2 RNA at 22 ° C, which had a higher partition (by approximately one order of magnitude) compared to other viruses and temperature conditions.…”

Solid-liquid partitioning of Dengue, West Nile, Zika, Hepatitis A, Influenza A, and SARS-CoV-2 viruses in wastewater from across the United States

“…RNA [32][33][34][35] in wastewater, only two studies have examined the partition of Influenza A RNA 7,36 .…”