tetano
Editor, Senior Moderator
Food Environ Virol
. 2021 Aug 20.
doi: 10.1007/s12560-021-09492-y. Online ahead of print.
Environmental Surveillance of SARS-CoV-2 RNA in Wastewater and Groundwater in Quintana Roo, Mexico
Gabriela Rosiles-González[SUP] 1 [/SUP], Victor Hugo Carrillo-Jovel[SUP] 1 [/SUP], Liliana Alzate-Gaviria[SUP] 2 [/SUP], Walter Q Betancourt[SUP] 3 [/SUP], Charles P Gerba[SUP] 3 [/SUP], Oscar A Moreno-Valenzuela[SUP] 4 [/SUP], Raúl Tapia-Tussell[SUP] 2 [/SUP], Cecilia Hernández-Zepeda[SUP] 5 [/SUP]
Affiliations
Abstract
The presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA in wastewater has been reported as a result of fecal shedding of infected individuals. In this study, the occurrence of SARS-CoV-2 RNA was explored in primary-treated wastewater from two municipal wastewater treatment plants in Quintana Roo, Mexico, along with groundwater from sinkholes, a household well, and submarine groundwater discharges. Physicochemical variables were obtained in situ, and coliphage densities were determined. Three virus concentration methods based on adsorption-elution and sequential filtration were used followed by RNA isolation. Quantification of SARS-CoV-2 was done by RT-qPCR using the CDC 2020 assay, 2019-nCoV_N1 and 2019-nCoV_N2. The Pepper mild mottle virus, one of the most abundant RNA viruses in wastewater was quantified by RT-qPCR and compared to SARS-CoV-2 concentrations. The use of three combined virus concentration methods together with two qPCR assays allowed the detection of SARS-CoV-2 RNA in 58% of the wastewater samples analyzed, whereas none of the groundwater samples were positive for SARS-CoV-2 RNA. Concentrations of SARS-CoV-2 in wastewater were from 1.8 × 10[SUP]3[/SUP] to 7.5 × 10[SUP]3[/SUP] genome copies per liter (GC l[SUP]-1[/SUP]), using the N1 RT-qPCR assay, and from 2.4 × 10[SUP]2[/SUP] to 5.9 × 10[SUP]3[/SUP] GC l[SUP]-1[/SUP] using the N2 RT-qPCR assay. Based on PMMoV prevalence detected in all wastewater and groundwater samples tested, the three viral concentration methods used could be successfully applied for SARS-CoV-2 RNA detection in further studies. This study represents the first detection of SARS-CoV-2 RNA in wastewater in southeast Mexico and provides a baseline for developing a wastewater-based epidemiology approach in the area.
Keywords: COVID-19; Groundwater; SARS-CoV-2; Viral indicators; Wastewater.
. 2021 Aug 20.
doi: 10.1007/s12560-021-09492-y. Online ahead of print.
Environmental Surveillance of SARS-CoV-2 RNA in Wastewater and Groundwater in Quintana Roo, Mexico
Gabriela Rosiles-González[SUP] 1 [/SUP], Victor Hugo Carrillo-Jovel[SUP] 1 [/SUP], Liliana Alzate-Gaviria[SUP] 2 [/SUP], Walter Q Betancourt[SUP] 3 [/SUP], Charles P Gerba[SUP] 3 [/SUP], Oscar A Moreno-Valenzuela[SUP] 4 [/SUP], Raúl Tapia-Tussell[SUP] 2 [/SUP], Cecilia Hernández-Zepeda[SUP] 5 [/SUP]
Affiliations
- PMID: 34415553
- DOI: 10.1007/s12560-021-09492-y
Abstract
The presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA in wastewater has been reported as a result of fecal shedding of infected individuals. In this study, the occurrence of SARS-CoV-2 RNA was explored in primary-treated wastewater from two municipal wastewater treatment plants in Quintana Roo, Mexico, along with groundwater from sinkholes, a household well, and submarine groundwater discharges. Physicochemical variables were obtained in situ, and coliphage densities were determined. Three virus concentration methods based on adsorption-elution and sequential filtration were used followed by RNA isolation. Quantification of SARS-CoV-2 was done by RT-qPCR using the CDC 2020 assay, 2019-nCoV_N1 and 2019-nCoV_N2. The Pepper mild mottle virus, one of the most abundant RNA viruses in wastewater was quantified by RT-qPCR and compared to SARS-CoV-2 concentrations. The use of three combined virus concentration methods together with two qPCR assays allowed the detection of SARS-CoV-2 RNA in 58% of the wastewater samples analyzed, whereas none of the groundwater samples were positive for SARS-CoV-2 RNA. Concentrations of SARS-CoV-2 in wastewater were from 1.8 × 10[SUP]3[/SUP] to 7.5 × 10[SUP]3[/SUP] genome copies per liter (GC l[SUP]-1[/SUP]), using the N1 RT-qPCR assay, and from 2.4 × 10[SUP]2[/SUP] to 5.9 × 10[SUP]3[/SUP] GC l[SUP]-1[/SUP] using the N2 RT-qPCR assay. Based on PMMoV prevalence detected in all wastewater and groundwater samples tested, the three viral concentration methods used could be successfully applied for SARS-CoV-2 RNA detection in further studies. This study represents the first detection of SARS-CoV-2 RNA in wastewater in southeast Mexico and provides a baseline for developing a wastewater-based epidemiology approach in the area.
Keywords: COVID-19; Groundwater; SARS-CoV-2; Viral indicators; Wastewater.