Table 3.

Viral genome loads (GC L⁻¹) in sewage sludge obtained by concentration methods following detection using qPCR.

Sampling date*	Viral groups
	HAdV		RV-A		NoV		HAV
Methods	1	2	1	2	1	2	1	2
January	2 × 104	7.4 × 104	0	0	0	0	0	0
February	0	9.4 × 104	0	0	0	0	8.6 × 106	0
	0	1.8 × 104	0	0	0	0	0	0
March	0	1.1 × 105	0	0	0	0	0	0
	0	4.9 × 104	0	0	0	2.4 × 105	0	0
April	3.1 × 104	3.6 × 104	0	0	0	0	0	0
	0	2.5 × 104	0	8 × 105	0	4.6 × 105	0	0
May	0	1.1 × 105	0	8 × 103	2.4 × 104	4 × 105	0	0
June	0	0	2 × 104	0	0	0	0	0
	0	8.7 × 104	0	2.4 × 105	1.6 × 104	5.4 × 104	0	0
July	0	5.3 × 104	0	4 × 105	4.9 × 105	1.2 × 105	0	0
	2 × 104	7.4 × 104	0	1 × 105	5 × 104	2.4 × 104	0	0
Frequency of detection	25%	91%	8%	41%	33%	50%	8%	0

Method 1 = ultracentrifugation, Method 2 = beef extract.

^*Samples were collected twice per month (except in Jan and May) with a 15 days intervals.