Journal Pre-proof J o u r n a l P r e -p r o o f 2 ABSTRACT Infection with SARS-CoV-2, the etiologic agent of the ongoing COVID-19 pandemic, is accompanied by the shedding of the virus in stool. Therefore, the quantification of SARS-CoV-2 in wastewater affords the ability to monitor the prevalence of infections amongst the population via wastewater-based epidemiology (WBE). In the current work, SARS-CoV-2 RNA was concentrated from wastewater in a catchment in Australia and viral RNA copies were enumerated using reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) resulting in two positive detections within a six day period from the same wastewater treatment plant (WWTP). The estimated RNA copy numbers observed in the wastewater were then used to estimate the number of infected individuals in the catchment via Monte Carlo simulation. Given the uncertainty and variation in the input parameters, the model estimated a median range of 171 to 1,090 infected persons in the catchment, which is in reasonable agreement with clinical observations. This work highlights the viability of WBE for monitoring infectious diseases, such as COVID-19, in communities. The work also draws attention to the need for further methodological and molecular assay validation for enveloped viruses in wastewater.Journal Pre-proof de Roda Husman, 2020;Medema et al., 2020;Wu et al., 2020). Here, we report the first evidence for the presence of SARS-CoV-2 RNA in wastewater in Australia. Our preliminary findings demonstrate the applicability of WBE for COVID-19 surveillance as a potential tool for public health monitoring at the community level. Journal Pre-proof conditions ranging from 3 × 20 s at 8,000 rpm at a 10 s interval. From here on RNA was extracted using RNeasy Power Microbiome kit as per manufacturer's instruction. Method B began with centrifugation of wastewater samples (100-200 mL) at 4,750 g for 30 mins. Supernatant was then removed carefully without disturbing the pellet and Journal Pre-proof 4 /reaction) of Oncorhynchus keta (O. keta) was added in the DNAse and RNAse free water and the Cq value obtained acted as a reference point. If the Cq value of a wastewater sample increases compared to the reference Cq value, the sample is considered to have PCR inhibitors. Wastewater samples with a 2-Cq (quantification cycle) delay was considered to have RT-qPCR inhibition (Staley et al., 2012). All RNA samples were Journal Pre-proof average quality of 15 (SLIDINGWINDOW:4:15). Reads were cropped to 120bp (CROP:120), with any less than 120bp in length discarded (MINLEN:120). Overlapping forward and reverse reads were merged using bbmerge from the BBMap suite (ver. 38.41, https://sourceforge.net/projects/bbmap/). Quality-controlled, merged reads were then mapped Journal Pre-proof describing it, through the model 10,000 times. For each estimate of infected persons, the corresponding prevalence was calculated by dividing the number of persons infected by the number of persons in the catchment. Sensitivity of the estimated number o...

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Exposure to specific airborne bacteria indoors is linked to infectious and noninfectious adverse health outcomes. However, the sources and origins of bacteria suspended in indoor air are not well understood. This study presents evidence for elevated concentrations of indoor airborne bacteria due to human occupancy, and investigates the sources of these bacteria. Samples were collected in a university classroom while occupied and when vacant. The total particle mass concentration, bacterial genome concentration, and bacterial phylogenetic populations were characterized in indoor, outdoor, and ventilation duct supply air, as well as in the dust of ventilation system filters and in floor dust. Occupancy increased the total aerosol mass and bacterial genome concentration in indoor air PM10 and PM2.5 size fractions, with an increase of nearly two orders of magnitude in airborne bacterial genome concentration in PM10. On a per mass basis, floor dust was enriched in bacterial genomes compared to airborne particles. Quantitative comparisons between bacterial populations in indoor air and potential sources suggest that resuspended floor dust is an important contributor to bacterial aerosol populations during occupancy. Experiments that controlled for resuspension from the floor implies that direct human shedding may also significantly impact the concentration of indoor airborne particles. The high content of bacteria specific to the skin, nostrils, and hair of humans found in indoor air and in floor dust indicates that floors are an important reservoir of human-associated bacteria, and that the direct particle shedding of desquamated skin cells and their subsequent resuspension strongly influenced the airborne bacteria population structure in this human-occupied environment. Inhalation exposure to microbes shed by other current or previous human occupants may occur in communal indoor environments.

Highlights SARS-CoV-2 was quantified (10 1 -10 4 copies 100 mL −1 ) in southeast Virginia wastewater. RT-ddPCR was optimized to quantify SARS-CoV-2 from wastewater. 5.5 and 7.6% recoveries were observed for BCoV and BRSV, respectively. Trends in SARS-CoV-2 are apparent at the facility and regional scaleover a 21-week study.