RESUMEN
The COVID-19 pandemic created a global crisis impacting not only healthcare systems, but also world economies and society. Recent data have indicated that fecal shedding of SARS-CoV-2 is common, and that viral RNA can be detected in wastewater. This suggests that wastewater monitoring is a potentially efficient tool for both epidemiological surveillance, and early warning for SARS-CoV-2 circulation at the population level. In this study we sampled an urban wastewater infrastructure in the city of Ashkelon, Israel, during the end of the first COVID-19 wave in May 2020 when the number of infections seemed to be waning. We were able to show varying presence of SARS-CoV-2 RNA in wastewater from several locations in the city during two sampling periods. This was expressed as a new index, Normalized Viral Load (NVL), which can be used in different area scales to define levels of virus activity such as red (high) or green (no), and to follow morbidity in the population at tested area. Our index showed the rise in viral load between the two sampling periods (one week apart) and indicated an increase in morbidity that was evident a month later in the population. Thus, this methodology may provide an early indication for SARS-CoV-2 infection outbreak in a population before an outbreak is clinically apparent. HIGHLIGHTSO_LIDetecting the presence of SARS-CoV-2 virus RNA in urban wastewater C_LIO_LIThe city sewer system may provide an early indication for SARS-CoV-2 infection and may be used as early warning for SARS-CoV-2 outbreaks C_LIO_LINVL index defines various infected urban zones from red (high) to green (low) C_LI Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=128 SRC="FIGDIR/small/20215244v1_ufig1.gif" ALT="Figure 1"> View larger version (54K): org.highwire.dtl.DTLVardef@360a84org.highwire.dtl.DTLVardef@1ec8004org.highwire.dtl.DTLVardef@1c8ae93org.highwire.dtl.DTLVardef@3d670c_HPS_FORMAT_FIGEXP M_FIG C_FIG
RESUMEN
SARS-CoV-2 is an RNA virus, a member of the coronavirus family of respiratory viruses that includes SARS-CoV-1 and MERS. COVID-19, the clinical syndrome caused by SARSCoV-2, has evolved into a global pandemic with more than 2,900,000 people infected. It has had an acute and dramatic impact on health care systems, economies, and societies of affected countries within these few months. Widespread testing and tracing efforts are employed in many countries in order to contain and mitigate this pandemic. Recent data has indicated that fecal shedding of SARS-CoV-2 is common, and that the virus can be detected in wastewater. This indicates that wastewater monitoring is a potentially efficient tool for epidemiological surveillance of SARS-CoV-2 infection in large populations at relevant scales. Collecting raw sewage data, representing specific districts, and crosslinking this data with the number of infected people from each location, will enable us to derive and provide quantitative surveillance tools. In particular, this will provide important means to (i) estimate the extent of outbreaks and their spatial distributions, based primarily on in-sewer measurements (ii) manage the early-warning system quantitatively and efficiently (and similarly, verify disease elimination). Here we report the development of a virus concentration method using PEG or alum, providing an important a tool for detection of SARS-CoV-2 RNA in sewage and relating it to the local populations and geographic information. This will provide a proof of concept for the use of sewage associated virus data as a reliable epidemiological tool.