SARS-CoV-2: sewage surveillance as an early warning system and challenges in developing countries

Transmission of novel coronavirus (SARS-CoV-2) in humans happens either through airway exposure to respiratory droplets from an infected patient or by touching the virus contaminated surface or objects (fomites). Presence of SARS-CoV-2 in human feces and its passage to sewage system is an emerging concern for public health. Pieces of evidence of the occurrence of viral RNA in feces and municipal wastewater (sewage) systems have not only warned reinforcing the treatment facilities but also suggest that these systems can be monitored to get epidemiological data for checking trend of COVID-19 infection in the community. This review summarizes the occurrence and persistence of novel coronavirus in sewage with an emphasis on the possible water environment contamination. Monitoring of novel coronavirus (SARS-CoV-2) via sewage-based epidemiology could deliver promising information regarding rate of infection providing a valid and complementary tool for tracking and diagnosing COVID-19 across communities. Tracking the sewage systems could act as an early warning tool for alerting the public health authorities for necessary actions. Given the impracticality of testing every citizen with limited diagnostic resources, it is imperative that sewage-based epidemiology can be tested as an early warning system. The need for the development of robust sampling strategies and subsequent detection methodologies and challenges for developing countries are also discussed. Graphical abstract