Table 2.

Comparative details of reported molecular detection of SARS-CoV-2 in the wastewater of various countries.

Country	State/city	Water type	Virus concentration method	Positive rate	Maximum concentration (copies/L)	RT-(q)PCR target region	Reference
India	Ahmedabad	Untreated wastewater	PEG precipitation of centrifugated supernatant	8 May: 100% 27 May:100%	5.6 × 10 3.5 × 102	ORF1ab gene S gene N gene	Present study
		Treated wastewater		8 May: 0% 27 May: 0%	–
Australia	Brisbane, Queensland	Untreated wastewater	Electronegative membrane-direct RNA extraction; ultrafiltration	2/9 (22%)	1.2 × 103	N gene	(Ahmed et al., 2020a, Ahmed et al., 2020b)
			Centricon (Merck) ultrafiltration of centrifugated supernatant	N_Sarbecco: 1/9 NIID_2019-nCOV_N: 0/9	1.9	N gene
The Netherlands	Amsterdam, The Hague, Utrecht, Apeldoorn, Amersfoort, Schiphol, Tilburg	Untreated wastewater	Centricon (Merck) ultrafiltration of centrifugated supernatant	14/24 (58%) N1: 14/24 N2: 0/24 N3: 8/24 E: 5/24	NA	N gene E gene	(Medema et al., 2020)
USA	Massachusetts	Untreated wastewater	PEG precipitation of filtered sample	N1: 4/6 N2: 1/6 N3: 4/6	N1: 104–2 × 105 N2: 3 × 104–105 N3: 104–105	N gene	(Wu et al., 2020b)
	Bozeman, Montana	Untreated wastewater	Corning Spin-X ultrafiltration of filtered sample	7/7 (100%) N1: 7/7 N2: 7/7	N1: 103–105 N2: 103–3 × 105	N gene	(Nemudryi et al., 2020)
	New Haven, Connecticut	Primary sludge	Direct RNA extraction	44/44	1.7 × 106–4.6 × 108	N gene	(Peccia et al., 2020)
France	Paris	Untreated wastewater	Ultracentrifugation	23/23 (100%)	>107.5	E gene	(Wurtzer et al., 2020)
		Treated wastewater		6/8 (75%)	~106	E gene
		Untreated wastewater		NA (100%)	104–107	E gene RdRp gene	(Wurtzer et al., 2020)
Italy	Milan and Rome,	Untreated wastewater	PEG/dextran precipitation of centrifuged supernatant	100% 12/12	NA (PCR detection)	ORF1ab gene S gene	(La Rosa et al., 2020)
China	Wuchang Fangcang Hospital	Untreated wastewater	PEG precipitation of centrifuged supernatant	0/4	0.05–1.87 × 105	ORF1 N gene	(Zhang et al., 2020)
		Treated wastewater		77% 7/9
Israel	Various locations	Untreated wastewater	Primary: PEG or Alum precipitation of centrifuged supernatant. Secondary: Amicon ultrafiltration	38% 10/26	NA	E gene	(Bar-Or et al., 2020)
Spain	Murcia	Untreated wastewater	Aluminium flocculation – beef extract precipitation	N1: 21/42 N2: 23/42 N3: 27/42	N1: 1.4 × 105 N2: 3.4 × 105 N3: 3.1 × 105	N gene	(Randazzo et al., 2020)
		Treated wastewater		Secondary: 2/18 Tertiary: 0/12	<2.5 × 105
	Ourense	Untreated wastewater	Amicon ultrafiltration of centrifugated supernatant	Influent: 5/5	NA	N gene E gene RdRp gene	(Balboa et al., 2020)
		Treated wastewater		Primary effluent: 1/4 Effluent: 0/5
		Sludge	Glycine/beef extract elution –centrifugation – filtration – PEG precipitation	41% 14/34
	Valencia	Untreated wastewater	Aluminium flocculation – beef extract precipitation	80% 12/15	105–106	N gene	(Randazzo et al., 2020)
		Treated wastewater		0/9	0
Turkey	Istanbul	Untreated wastewater	Amicon ultrafiltration OR PEG precipitation of centrifuged supernatant	77% 7/9	103–106	RdRp gene	(Kocamemi et al., 2020)