**3.2 Wastewater surveillance system**

There is growing proof of presence of SARS-CoV-2 in the sewage [51, 52]. Multiple focused researches have been carried out to analyze the presence of virus in wastewater [53]. Many studies have proved wastewater based epidemiology as an eligible and effective tracking tool in detecting SARS-CoV-2 genome at ambient temperature of 45°C giving us a better understanding of the present spreading of the global pandemic. This has led to growing concern in public health authorities for the essential need of the analysis of sewage samples from the sewage treatment plants for computing the presence of viral genome of SARS-CoV-2. While this is a

**Figure 4.** *Analysis of disease prevalence using wastewater samples.*

grave concern, it has also presented as an opportunity for the utilization of waterbased surveillance system for monitoring and investigating the presence of virus in sewage. The detection of virus in the wastewater samples has created a further possibility that the wastewater containing the virus can also release the same virus into other water bodies such as sea, groundwater, etc. The samples can be collected from drains and sewage treatment plants to understand the load of virus being shed by a particular community [54, 55]. The samples once taken, can be analyzed for load of virus present in it, followed by data analytics to back calculate the disease prevalence in an area. **Figure 4** represent the analysis of wastewater samples for COVID-19 prevalence.

Through wastewater sample analysis, the disease prevalence calculation can serve as an early warning for spreading pandemic in an area. This may give the authorities to act in timely manner for management of proliferation of COVID-19 in the area considered for analysis. Wastewater surveillance comes along with many benefits such as it is an economical method and also acts as a early warning tool signaling the transmission of the disease by neglecting the other epidemiological indicators and gives successful evidences and results [55].
