Shaping the subway microbiome through probiotic-based sanitation during the COVID-19 emergency: a pre–post case–control study

Table 2 Environmental SARS-CoV-2 contamination

Train	Time	N° positive/ total samples	Surface type	Load (^a)
CTR	T0	2/136	Floor, Floor	4–9
	T1	2/136	Floor, Floor	6.8–10.5
	T2	2/136	Floor, Floor	8.5–12.4
	T3	3/136	Floor, Floor, Seat	10–21–18.5
	T4	3/136	Floor, Floor, Seat	24–10–27
	T5	3/136	Floor, Floor, Seat	14–26–17.6
PCHS	T0	1/136	Floor	4.6
	T1	0/136	-	-
	T2	2/136	Floor, Floor	9.4–4.6
	T3	0/136	-	-
	T4	1/136	Floor	4.8
	T5	2/136	Floor, Seat	5.2–6.1

^aVirus load is expressed as genome copy number per sample (positivity: ≥ 3copies/sample in 20 µL); each sampling campaign consisted of 10 or 12 samples, depending on the availability of air filters

ISSN: 2049-2618