Table 1.
Occurrence of SARS-CoV-2 RNA in wastewater and various viral detection techniques.
| Continent | Country | Type of wastewater sample | Virus concentration method | Detection method | Positive result rate (%) | Range of concentration (copies/L) | RNA target genes | References |
|---|---|---|---|---|---|---|---|---|
| North America | USA | Untreated wastewater | Ultrafiltration and adsorption-eluting using electronegative membrane | Nested PCR and RT-qPCR | 2/7 = 28.6% | 3.1 × 103–7.5 × 103 | ORF 1a, S | Sherchan et al. (2020) |
| Secondary treated | 0/4 = 0% | N | ||||||
| Final effluent | 0/4 = 0% | |||||||
| USA | Untreated wastewater | Polyethylene glycol-8000 (PEG 8000) | RT-qPCR | 2/2 = 100% | 57–303 copies/mL | N1, N2, N3 | Wu et al. (2020b) | |
| 10/10 = 100% | ||||||||
| USA | Untreated wastewater | Corning Spin X-ultrafiltration | RT-qPCR | 7/7 = 100% | >3 × 104 | N | Nemudryi et al. (2020) | |
| Europe | Italy | Untreated wastewater | Polyethylene glycol (PEG) and dextran (DEX) or PEG-dextran | Nested PCR and RT-qPCR | 6/12 = 50% | Not detected | ORF 1 ab | La Rosa et al. (2020b) |
| Italy | Untreated wastewater | Ultrafiltration | RT-qPCR | 4/8 = 50.0% | – | 2019-nCoV, ORF 1 ab, E_Sarbeco | Rimoldi et al. (2020) | |
| Treated wastewater | Not detected | – | ||||||
| Italy | Untreated wastewater | Ultrafiltration over ultracentrifugation or PEG precipitation | RT-qPCR | 4/9 = 44.4% | – | ORF ab, N | Baldovin et al. (2021) | |
| Tertiary treated | 2/2 = 100% | |||||||
| Germany | Untreated wastewater | Electronegative membrane filter | RT-qPCR | 2/2 = 100% | 4 × 1011–1 × 1015 copies/day | N, S, ORF 1 ab | Agrawal et al. (2021) | |
| Spain | Untreated wastewater | Aluminium flocculation-beef exact precipitation | RT-qPCR | 12/15 = 80.0% | 104–105 | N | Randazzo et al. (2020a) | |
| Treated wastewater | 0/9 = 0% | 0 | ||||||
| Spain | Untreated wastewater | Aluminum hydroxide adsorption-precipitation | RT-qPCR | 35/42 = 83.3% | 1 × 105–3.4 × 105 | N | Randazzo et al. (2020b) | |
| Treated secondary | 2/18 = 11.1% | <2.5 × 104 | ||||||
| Treated tertiary | 0/12 = 0% | Not available | ||||||
| Spain | Untreated wastewater | Amicon ultrafiltration of centrifugated supernatant | RT-qPCR | 5/5 = 100% | – | N, E, RdRP | Balboa et al. (2021) | |
| Treated wastewater | 1/4 = 25.0% | |||||||
| France | Untreated wastewater | Ultracentrifugation | RT-qPCR | 23/23 = 100% | 5 × 104 GU/L | RdRP, E | Wurtzer et al. (2020) | |
| Treated wastewater | 6/8 = 75.0% | 3 × 106 GU/L | ||||||
| Netherlands | Untreated wastewater | Ultrafiltration | RT-qPCR | 14/24 = 58.3% | 2 × 103–2.2 × 106 | N, E | Medema et al. (2020) | |
| Asia | Japan | Untreated wastewater | Electronegative membrane-direction RNA exaction; ultrafiltration | RT-qPCR | 0/5 = 0% | Not available | N | Haramoto et al. (2020) |
| Secondary wastewater | 1/5 = 20.0% | 2 .4 × 103 | ||||||
| Japan | Untreated wastewater | PEG precipitation | RT-qPCR | 7/17 = 41.2% | 4.4 × 104 | N2, N3, NIID_2019-nCoV_N | Hata et al. (2021) | |
| China | Untreated wastewater | PEG precipitation of centrifugation supernatant | RT-qPCR | 0/4 = 0% | Not available | ORF 1, N | Zhang et al. (2020) | |
| Treated wastewater | 7/9 = 77.8% | 0.5 × 103–18.7 × 103 | ||||||
| India | Untreated wastewater | PEG and NaCl centrifugation | RT-qPCR | 5/12 = 41.7% | – | RdRP, ORF 1 ab, E, S, N | Arora et al. (2020) | |
| Treated wastewater | 0/6 = 0% | |||||||
| India | Untreated wastewater | PEG precipitation | RT-qPCR | 2/2 = 100% | 0.78 × 102–8.05 × 102 | ORF 1 ab, N, S | Kumar et al. (2020b) | |
| Untreated wastewater | Adsorption | rRT-PCR | 6/17 = 35.3% | RdRP, ORF 1 ab, E, S, N | ||||
| India | Upflow anaerobic sludge blanket (UASB) | PEG precipitation of centrifugated supernatant | RT-qPCR | – | 3.5 × 103 | ORF 1 ab, N, S | Kumar et al. (2021) | |
| Aeration pond | 1.5 × 102 | ORF 1 ab | ||||||
| Iran | Treated wastewater (Final effluent) | Adsorption-elution technique using electronegative filter | RT-qPCR | 8/10 = 80.0% | 101–103 | ORF 1 ab, N | Tanhaei et al. (2021) | |
| Iran | Untreated wastewater | PEG 6000 | RT-qPCR | 12/12 = 100% | – | ORF 1 ab, N | Nasseri et al. (2021) | |
| Treated wastewater | 2/12 = 16.7% | |||||||
| Israel | Untreated wastewater | Primary: PEG or Alum; precipitation; secondary: Amicon ultrafiltration | RT-qPCR | 10/26 = 38.5% | – | E | Bar Or et al. (2020) | |
| Turkey | Untreated wastewater | Ultracentrifugation, PEG8000-adsorption electronegative membrane and ultrafiltration | RT-qPCR | 7/9 = 77.8% | 9.33 × 104 | RdRP | Kocamemi et al. (2020) | |
| The United Arab Emirates (UAE) | Untreated wastewater-WWTP | Ultrafiltration columns, and PEG/TRIzol | RT-qPCR | 28/36 = 77.8% | 7.50E + 02 – 3.40E + 04 | RdRP | Hasan et al. (2021) | |
| Untreated wastewater (38 other locations) | 30/38 = 78.9% | 2.86E + 02 – 2.90E + 04 | ||||||
| 11 WWTP treated effluent | Not detected | – | ||||||
| Qatar | Influent wastewater (Untreated wastewater) | PEG | RT-qPCR | 100% | 7,889 ± 1421 – 542,056 ± 25,775 copy/L | N | Saththasivam et al. (2021) | |
| Saudi Arabia | Untreated wastewater | Electronegative membrane | RT-qPCR | 43/57 = 75.4% | – | N1, N2, N3 | Hong et al. (2021) | |
| Pakistan | Untreated wastewater | PEG/dextran precipitation of centrifuged supernatant | RT-qPCR | 21/78 = 26.9% | – | ORF 1a | Sharif et al. (2020) | |
| Oceania | Australia | Untreated wastewater | Electronegative membrane-direct RNA exaction; ultrafiltration | RT-qPCR | 2/9 = 22.2% | 1.9 × 101–1.2 × 102 | N | Ahmed et al. (2020b) |