Table 3.

Summary on how the reviewed viruses meet the criteria for wastewater indicator.

Criterion	AdV	PyV	AiV	PMMoV	FRNAP (II/III)	Culturable Bacteroides phages	CrAssphage
Methods used for detection in environmental samples	qPCR; ICC-qPCR; culturing	qPCR	qRT-PCR	qRT-PCR; plant infectivity assay	qRT-PCR; culturing	culturing	qPCR
Human association	Human-specific	Human-specific	Human-specific	Human waste and agricultural sites	Primarily human gut-associated	Primarily human gut-associated, have been found in animal faeces at low titres	Primarily human gut-associated, have been found in animal faeces at low titres
Concentration in wastewater (gc/l)	1 × 101 – 3 × 1011	1 × 103 – 6 × 108	1 × 104 – 4 × 106	3 × 105 – 2 × 1010	4 × 103-2x109	1 × 101 – 6 × 106	2 × 105 – 1 × 1012
Log10 removal during wastewater treatment	0.2–5.5 (n = 500)	0.3–4.2 (n = 407)	0.8–2.7 (n = 72)	0–2.7 (n = 106)	0.1–3.1 (n = 172)	0.5–5.6 (n = 304)	1–1.2 (n = 39)
Concentration in the aquatic environment (gc/l)	4–2 × 1010	1–1 × 107	7 × 101 – 8 × 108	1 × 101 – 8 × 108	0.2–2x106	1–2 × 105	1 × 103 – 3 × 107
Global distribution and temporal stability	Detected in clinical samples globally; limited seasonal variations	Detected in clinical samples globally; limited seasonal variations	Detected in clinical samples globally; limited seasonal variations	Detected in clinical samples globally; limited seasonal variations	Detected in clinical samples globally; limited seasonal variations	Detected in clinical samples globally; limited seasonal variations	Detected in clinical samples globally; limited seasonal variations