Fast and effective surveillance systems are the bedrock of prevention, and control of infectious outbreak which different health entities around the world are working on it [1-3]^[1][2][3]. In a pandemic situation, with time limitations and restrict access to massive diagnostic an alternative approach as a complementary tool to investigate virus circulation in the community is essential [4]^[4].

The importance of such a surveillance system has been more highlighted with the emergence of coronavirus respiratory disease (COVID-19) In December 2019, Wuhan, China[2, 4]^[2][4].

Since many SARS-CoV-2 patients are might exhibit few or non-specific symptoms, rapid and accurate diagnosis of potential virus carriers and identification of asymptomatic cases is a critical step to suppress the risk of disease transmission at the early stage^[5].

Wastewater-based epidemiology (WBE) provides comprehensive information on community health status in near real-time based upon analyses of wastewater compounds. All the physical, chemical and biological substances of the community are excreted to the sewer systems and transported to wastewater treatment plants (WWTP) that serving defined catchment areas.[2] so wastewater analysis could be equivalent to community-based urine and fecal analysis that can give a reflection of community health state[3, 6, 7]^[3][6][7].

This approach was previously used to monitoring pharmaceutical consumption, early detection of infectious outbreaks, and detection of viral pathogens such as adenovirus, poliovirus and hepatitis A^[8]. Since the first report of SARS-CoV2 detection in patient’s feces and identification of virus genomes in wastewater in the Netherlands, Australia, and Paris, France, WBE has been proposed as a surveillance tool to investigate the presence and prevalence of the virus in the community[9, 10]^[9][10]. In the situation of limited and time-consuming diagnostic tests monitoring sewage systems could provide a better estimate of the spread of the virus and determine whether there are potential cases because wastewater surveillance can also account for those who have only mild or no symptoms^[11].

Early and population-wide scale analysis, represent the WBE as a potential early warning tool to strengthen health entity's preparedness and limit the health and economic burden caused in (re) emergence of the infectious outbreak^[3].

Despite the promising aspects of utilizing WBE in COVID-19 surveillance, there are still challenges in representative sampling, virus recovery, and concentration methods as well as population normalization and ethical issues that should be considered^[12].

1. Organization, W.H., WHO guidelines on ethical issues in public health surveillance. 2017.
2. Sims, N. and B.J.E.i. Kasprzyk-Hordern, Future perspectives of wastewater-based epidemiology: monitoring infectious disease spread and resistance to the community level. 2020. 139: p. 105689.
3. Xagoraraki, I. and E. O’Brien, Wastewater-based epidemiology for early detection of viral outbreaks, in Women in water quality. 2020, Springer. p. 75-97.
4. Medema, G., et al., Presence of SARS-Coronavirus-2 RNA in sewage and correlation with reported COVID-19 prevalence in the early stage of the epidemic in the Netherlands. 2020. 7(7): p. 511-516.
5. Mao, K., H. Zhang, and Z. Yang, Can a paper-based device trace COVID-19 sources with wastewater-based epidemiology? 2020, ACS Publications.
6. Sinclair, R.G., et al., Pathogen surveillance through monitoring of sewer systems. 2008. 65: p. 249.
7. Mallapaty, S.J.N., How sewage could reveal true scale of coronavirus outbreak. 2020. 580(7802): p. 176-177.
8. Ahmed, W., et al., First confirmed detection of SARS-CoV-2 in untreated wastewater in Australia: a proof of concept for the wastewater surveillance of COVID-19 in the community. 2020. 728: p. 138764.
9. Barcelo, D.J.J.o.E.C.E., An environmental and health perspective for COVID-19 outbreak: meteorology and air quality influence, sewage epidemiology indicator, hospitals disinfection, drug therapies and recommendations. 2020. 8(4): p. 104006.
10. Wu, F., et al., SARS-CoV-2 titers in wastewater are higher than expected from clinically confirmed cases. 2020. 5(4): p. e00614-20.
11. Wurtzer, S., et al., Time course quantitative detection of SARS-CoV-2 in Parisian wastewaters correlates with COVID-19 confirmed cases. 2020: p. 2020.04.12.20062679.
12. Polo, D., et al., Making waves: Wastewater-based epidemiology for COVID-19–approaches and challenges for surveillance and prediction. 2020. 186: p. 116404.