RESUMEN
COVID-19 positive patients can egest live SARS-CoV-2 virus and viral genome fragments through faecal matter and urine, raising concerns about viral transmission through faecal-oral route and/or contaminated aerosolized water. These worries are heightened in many low and middle income nations, where raw sewage is often dumped into surface waterways and open defecation betide. In this manuscript, we attempt to discern the presence of SARS-CoV-2 genetic material (ORF-1ab, N and S genes) in two urban cities of India viz., Ahmedabad, in western India with several WWTPs; and Guwahati in the north-eastern part of the country with no such treatment plants. The study was carried out to establish applicability of WBE for COVID-19 surveillance as a potential tool for public health monitoring at the community level. 25.8% and 20% of the surface water samples had detectable SARS-CoV-2 RNA load in Ahmedabad and Guwahati, respectively. The high concentration of gene (ORF-1ab - 800 copies/L for Sabarmati river, Ahmedabad and S-gene - 565 copies/L for Bharalu urban river, Guwahati) found in natural waters indicates WWTPs do not always completely remove the genetic material of the virus. The study shows the applicability of WBE surveillance of COVID-19 in cities with low sanitation as well as in rural areas. The method used in this study cannot detect the live viruses, hence further research is required to evaluate the transmission implication of COVID-19 via ambient water, if any. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=112 SRC="FIGDIR/small/21258829v3_ufig1.gif" ALT="Figure 1"> View larger version (45K): org.highwire.dtl.DTLVardef@19a51dborg.highwire.dtl.DTLVardef@743707org.highwire.dtl.DTLVardef@1c8b608org.highwire.dtl.DTLVardef@26cd43_HPS_FORMAT_FIGEXP M_FIG C_FIG HighlightsO_LINatural urban waters show the presence of SARS-CoV-2 RNA. C_LIO_LILake water receiving runoff containing SARS-CoV-2 genes reflected positive sign early C_LIO_LIViral RNA in surface water reflects incomplete removal of gene fragments in WWTPs. C_LIO_LIResidence time and fate owing to viral RNA in natural waters needs further research. C_LI
