Wastewater-based epidemiology has potential as an early-warning tool for determining the presence of COVID-19 in a community. The University of Arizona (UArizona) utilized WBE paired with clinical ...testing as a surveillance tool to monitor the UArizona community for SARS-CoV-2 in near real-time, as students re-entered campus in the fall. Positive detection of virus RNA in wastewater lead to selected clinical testing, identification, and isolation of three infected individuals (one symptomatic and two asymptomatic) that averted potential disease transmission. This case study demonstrated the value of WBE as a tool to efficiently utilize resources for COVID-19 prevention and response. Thus, WBE coupled with targeted clinical testing was further conducted on 13 dorms during the course of the Fall semester (Table 3). In total, 91 wastewater samples resulted in positive detection of SARS-CoV-2 RNA that successfully provided an early-warning for at least a single new reported case of infection (positive clinical test) among the residents living in the dorm. Overall, WBE proved to be an accurate diagnostic for new cases of COVID-19 with an 82.0% positive predictive value and an 88.9% negative predictive value. Increases in positive wastewater samples and clinical tests were noted following holiday-related activities. However, shelter-in-place policies proved to be effective in reducing the number of daily reported positive wastewater and clinical tests. This case study provides evidence for WBE paired with clinical testing and public health interventions to effectively contain potential outbreaks of COVID-19 in defined communities.
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•Positive detection of SARS-CoV-2 RNA in wastewater led to selected clinical testing.•WBE identified one symptomatic and two asymptomatic individuals in a dorm.•79 positive wastewater samples provided early warnings of infection(s) in 13 dorms.•Cases increased following holidays and shelter-in-place policies proved effective.•WBE paired with clinical testing and interventions effectively contained outbreaks.
Peracetic acid (PAA) is an alternative to traditional wastewater disinfection as it has a high oxidation potential without producing chlorinated disinfection byproducts. Reports have shown the ...effectiveness of PAA to reduce waterborne viruses, but the mechanism of inactivation is understudied. This study evaluated PAA consumption by amino acids and nucleotides that are the building blocks of both viral capsids and genomes. Cysteine (>1.7 min–1) and methionine (>1.2 min–1) rapidly consumed PAA, while cystine (1.9 × 10–2 min–1) and tryptophan (1.4 × 10–4 min–1) reactions occurred at a slower rate. All other amino acids and nucleotides did not react significantly (p < 0.05) with PAA during experiments. Also, PAA treatment did not result in significant (p < 0.05) reductions of purified RNA from MS2 bacteriophage and murine norovirus. Data in this study suggest that PAA effectively inactivates viruses by targeting susceptible amino acids on capsid proteins and does not readily damage viral genomes. Knowledge of virus capsid structures and protein compositions can be used to qualitatively predict the relative resistance or susceptibility of virus types to PAA. Capsid structures containing a higher total number of target amino acids may be more susceptible to PAA reactions that damage structural integrity resulting in inactivation.
We investigated the presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA in wastewater samples in southern Louisiana, USA. Untreated and treated wastewater samples were ...collected on five occasions over a four-month period from January to April 2020. The wastewater samples were concentrated via ultrafiltration (Method A), and an adsorption–elution method using electronegative membranes (Method B). SARS-CoV-2 RNA was detected in 2 out of 15 wastewater samples using two reverse transcription-quantitative polymerase chain reaction (RT-qPCR) assays (CDC N1 and N2). None of the secondary treated and final effluent samples tested positive for SARS-CoV-2 RNA. To our knowledge, this is the first study reporting the detection of SARS-CoV-2 RNA in wastewater in North America, including the USA. However, concentration methods and RT-qPCR assays need to be refined and validated to increase the sensitivity of SARS-CoV-2 RNA detection in wastewater.
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•First study in Louisiana, USA reporting the detection of SARS-CoV-2 RNA in wastewater using ultrafiltration.•Two out of seven untreated wastewater samples tested positive for SARS-CoV-2 RNA.•None of the secondary treated and final effluent samples tested positive.•Concentration methods and RT-qPCR assays applied for SARS-CoV-2 RNA detection need further refinement.
Wastewater-based epidemiology (WBE) was utilized to monitor SARS-CoV-2 RNA in sewage collected from manholes specific to individual student dormitories (dorms) at the University of Arizona in the ...fall semester of 2020, which led to successful identification and reduction of SARS-CoV-2 transmission events. Positive wastewater samples triggered clinical testing of residents within that dorm; thus, SARS-CoV-2 infected individuals were identified regardless of symptom expression. This current study examined clinical testing data to determine the abundance of asymptomatic versus symptomatic cases in these defined communities. Nasal and nasopharyngeal swab samples processed via antigen and PCR tests indicated that 79.2% of SARS-CoV-2 infections were asymptomatic, and only 20.8% of positive cases reported COVID-19 symptoms at the time of testing. Clinical data was paired with corresponding wastewater virus concentrations, which enabled calculation of viral shedding rates in feces per infected person. Mean shedding rates averaged from positive wastewater samples across all dorms were 7.30 ± 0.67 log10 genome copies per gram of feces (gc/g-feces) based on the N1 gene. Quantification of SARS-CoV-2 fecal shedding rates from infected individuals has been the critical missing component necessary for WBE models to measure and predict SARS-CoV-2 infection prevalence in communities. The findings from this study can be utilized to create models that can be used to inform public health prevention and response actions.
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•Wastewater-based epidemiology with clinical testing monitored SARS-CoV-2 in dorms.•79.2% of SARS-CoV-2 infections were asymptomatic, and 20.8% were symptomatic.•Clinical and wastewater data aggregated to estimate SARS-CoV-2 fecal shedding rate.•Mean fecal shedding rate based on the N1 gene was 7.30 ± 0.67 log10 gc/g-feces.
The present study investigated wastewater treatment for the removal of 11 different virus types (pepper mild mottle virus; Aichi virus; genogroup I, II, and IV noroviruses; enterovirus; sapovirus; ...group-A rotavirus; adenovirus; and JC and BK polyomaviruses) by two wastewater treatment facilities utilizing advanced Bardenpho technology and compared the results with conventional treatment processes. To our knowledge, this is the first study comparing full-scale treatment processes that all received sewage influent from the same region. The incidence of viruses in wastewater was assessed with respect to absolute abundance, occurrence, and reduction in monthly samples collected throughout a 12 month period in southern Arizona. Samples were concentrated via an electronegative filter method and quantified using TaqMan-based quantitative polymerase chain reaction (qPCR). Results suggest that Plant D, utilizing an advanced Bardenpho process as secondary treatment, effectively reduced pathogenic viruses better than facilities using conventional processes. However, the absence of cell-culture assays did not allow an accurate assessment of infective viruses. On the basis of these data, the Aichi virus is suggested as a conservative viral marker for adequate wastewater treatment, as it most often showed the best correlation coefficients to viral pathogens, was always detected at higher concentrations, and may overestimate the potential virus risk.
Candida auris is an opportunistic fungal pathogen and an emerging global public health threat, given its high mortality among infected individuals, antifungal resistance, and persistence in ...healthcare environments. This study explored the applicability of wastewater surveillance for C. auris in a metropolitan area with reported outbreaks across multiple healthcare facilities. Influent or primary effluent samples were collected over 10 weeks from seven sewersheds in Southern Nevada. Pelleted solids were analyzed using an adapted quantitative polymerase chain reaction (qPCR) assay targeting the ITS2 region of the C. auris genome. Positive detection was observed in 72 of 91 samples (79%), with higher detection frequencies in sewersheds serving healthcare facilities involved in the outbreak (94 vs 20% sample positivity). Influent wastewater concentrations ranged from 2.8 to 5.7 log10 gene copies per liter (gc/L), and primary clarification achieved an average log reduction value (LRV) of 1.24 ± 0.34. Presumptive negative surface water and wastewater controls were non-detect. These results demonstrate that wastewater surveillance may assist in tracking the spread of C. auris and serve as an early warning tool for public health action. These findings provide the foundation for future application of wastewater-based epidemiology (WBE) to community- or facility-level surveillance of C. auris and other high consequence, healthcare-associated infectious agents.
Previous studies show that SARS-CoV-2 waste shedding rates vary by community and are influenced by multiple factors; however, differences in shedding rates across multiple variants have yet to be ...evaluated. The purpose of this work is to build on previous research that evaluated waste shedding rates for early SARS-CoV-2 and the Delta variant, and update population level waste shedding rates for the more-recent Omicron variant in six communities. Mean SARS-CoV-2 waste shedding rates were found to increase with the predominance of the Delta variant and subsequently decrease with Omicron infections. Interestingly, the Delta stage had the highest mean shedding rates and was associated with the most severe disease symptoms reported in other clinical studies, while Omicron, exhibiting reduced symptoms, had the lowest mean shedding rates. Additionally, shedding rates were most consistent across communities during the Omicron stage. This is the first paper to identify waste shedding rates specific to the Omicron variant and fills a knowledge gap critical to disease prevalence modeling.
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•Pandemic progression and variants influence SARS-CoV-2 waste shedding rates.•Waste shedding rates increased with Delta predominance and decreased with Omicron.•Omicron-specific waste shedding rates ranged between 7.67 and 8.23 log10 gc/g-feces.•Shedding rates were most consistent across communities during the Omicron stage.•Waste shedding rates mirrored disease severity reported in other clinical studies.
•Criteria were established for identifying suitable surrogates for water reuse.•11 viruses, two phage, and three bacteria were monitored throughout a reuse scheme.•Virus pathogens are effectively ...removed throughout water reuse treatment.•PMMoV, AiV, GII NoV, AdV, FRNA GII were suggested as potential virus surrogates.•Surrogate monitoring can inform water reuse performance for public health safety.
Water reuse as an alternative water supply is increasing throughout the world due to water stress and scarcity; however, there are no standard practices for monitoring virus pathogens in such systems. This study aimed to identify suitable surrogates for virus fate, transport, and removal throughout a water reuse scheme. Various microbial targets (11 viruses, two phage, and three bacteria) were monitored using molecular and culture methods across all treatment stages in a wastewater reclamation facility and advanced water treatment facility. Criteria were established for identifying suitable surrogates, which included reliable detection, observable fate and transport, calculable log-reduction values (LRVs), correlations with other targets, and various morphological types. In total, five viruses (PMMoV, AiV, GII NoV, AdV, FRNA GII) met these stringent criteria and were suggested as potential virus surrogates. These surrogates enabled successful comparison of assigned versus actual LRVs throughout a water reuse scheme. Results suggest that virus pathogens are effectively removed throughout water reuse treatment and the suggested surrogates can be utilized for monitoring treatment performance and ensuring public health safety. This study provides a framework that water utilities across the world can reference for establishing virus monitoring practices.
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Next generation sequencing provides new insights into the diversity and ecophysiology of bacteria communities throughout wastewater treatment plants (WWTP), as well as the fate of pathogens in ...wastewater treatment system. In the present study, we investigated the bacterial communities and human-associated Bacteroidales (HF183) marker in two WWTPs in North America that utilize Bardenpho treatment processes. Although, most pathogens were eliminated during wastewater treatment, some pathogenic bacteria were still observed in final effluents. The HF183 genetic marker demonstrated significant reductions between influent and post-Bardenpho treated samples in each WWTP, which coincided with changes in bacteria relative abundances and community compositions. Consistent with previous studies, the major phyla in wastewater samples were predominantly comprised by Proteobacteria (with Gammaproteobacteria and Alphaproteobacteria among the top two classes), Actinobacteria, Bacteroidetes, and Firmicutes. Dominant genera were often members of Proteobacteria and Firmicutes, including several pathogens of public health concern, such as Pseudomonas, Serratia, Streptococcus, Mycobacterium and Arcobacter. Pearson correlations were calculated to observe the seasonal variation of relative abundances of gene sequences at different levels based on the monthly average temperature. These findings profile how changes in bacterial communities can function as a robust method for monitoring wastewater treatment quality and performance for public and environmental health purposes.
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•NGS enables insights to bacterial community compositions in Bardenpho bioreactors.•Bardenpho exhibited high bacteria removals, but effluents contained pathogens.•HF183 genetic marker demonstrated significant reductions between influent and effluent samples in each WWTP.•Major phyla: Proteobacteria, Actinobacteria, Bacteroidetes, and Firmicutes.•Knowledge on the microbial community structure can help engineers develop and optimize Bardenpho system.
Wastewater-based epidemiology (WBE) has been utilized as an early warning tool to anticipate disease outbreaks, especially during the COVID-19 pandemic. However, COVID-19 disease models built from ...wastewater-collected data have been limited by the complexities involved in estimating SARS-CoV-2 fecal shedding rates. In this study, wastewater from six municipalities in Arizona and Florida with distinct demographics were monitored for SARS-CoV-2 RNA between September 2020 and December 2021. Virus concentrations with corresponding clinical case counts were utilized to estimate community-wide fecal shedding rates that encompassed all infected individuals. Analyses suggest that average SARS-CoV-2 RNA fecal shedding rates typically occurred within a consistent range (7.53–9.29 log10 gc/g-feces); and yet, were unique to each community and influenced by population demographics. Age, ethnicity, and socio-economic factors may have influenced shedding rates. Interestingly, populations with median age between 30 and 39 had the greatest fecal shedding rates. Additionally, rates remained relatively constant throughout the pandemic provided conditions related to vaccination and variants were unchanged. Rates significantly increased in some communities when the Delta variant became predominant. Findings in this study suggest that community-specific shedding rates may be appropriate in model development relating wastewater virus concentrations to clinical case counts.
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•Wastewater data were utilized to calculate 6-day peak shedding rates.•Fecal shedding rates were estimated for communities with different demographics.•Age, ethnicity, and socio-economic factors may have influenced shedding rates.•Populations with median age 30–39 generally had greater fecal shedding rates.•In some communities, shedding rate increased with rise of Delta variant infections.
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