Table 2.

Clinical evidence of SARS-CoV-2 screened from wastewater across different countries from the year 2020–2021.

Country	Month/Year	Sample	Analysis	References
India	June/2020	Wastewater from hospital	•SARS-CoV-2 RNA detection was 100% in wastewater •Virus load 10 fold higher in wastewater, effluent and sewage •Early RNA detection preceding the increase in infection rate from 9 to 12 days	[88,90,91]
Brazil	May/2020	Wastewater	•SARS-CoV-2 RNA concentration was 41.7%–100% in wastewater •Virus screening was conducted with samples based on infection rate and detectable possibilities •Screening was in coherence with positive reports and epidemiological data	[[72], [73], [74],127]
USA	March/2020	Urban treatment plant, wastewater from catchment points	•High positive reports of SARS-CoV-2 infection •Viral RNA concentration was 40% in the screened samples •High virus copy number preceded infection rates in 1–12 days	[35,[75], [76], [77], [78]]
Netherlands	March/2020	Wastewater	•Viral RNA was detected in wastewater from six major cities •Virus detection rate was found to be 69% and detectable count preceded the infection in 4–8 days •Significant expression was observed in early detection	[79,128]
France	July/2020	Wastewater treatment plant	•Viral RNA was detected in the wastewater (100%) •The detection of genome copy was fifty in the post-lockdown phase in the month of June •Early detection was reported based on clinical data which preceded 2–5 days of COVID-19 infection •High copy number was reported in the wastewater in accordance with the increase COVID-19 cases	[80,100]
Germany	April/2020	Wastewater treatment plant	•High expression of viral RNA in the sample (100%) •Sequencing reported high viral copy number with the surge in infection cases •Total load of virus copy number was in coherence with the clinical data of COVID-19 infection	[81]
Italy	April/2020	Wastewater	•Viral RNA was detected in the sample water (50%) positive cases •Viral RNA concentration was detected significantly in early clinical evaluations	[82,83]
China	July/2020	Septic tanks	•SARS-CoV-2 RNA was detected in 60% out of the total sample pool •Viral RNA was not observed significantly in effluent after disinfection	[85]
Bangladesh	August/2020	Wastewater	•High load of viral RNA was reported	[109]
Australia	April/2020	Wastewater	•Viral RNA concentration was 22.2% in the wastewater	[86]
Israel	Not reported	Wastewater	•Viral RNA concentration was 38.4% in hospital wastewater	[87]