Table. 3.

Number and percentage of viral RNA detected by RT-PCR or positive viral isolation in cultures of respiratory samples during SARS-CoV-2 (Omicron variant) infection, Japan.

Interval in days	Number (n) and percentage (%) of RT-PCR positive samples	Number (n) and percentage (%) of positive viral isolation	Number (n) and percentage (%) of positive viral isolation in RT-PCR-positive samples
Since symptom onset	Symptomatic cases only; n (%)
1–2 days	15/16 (93.8)	2/16 (12.5)	2/15 (13.3)
3–6 days	8/8 (100)	4/8 (50)	4/8 (50)
7–9 days	16/16 (100)	3/16 (18.8)	3/16 (18.8)
10–13 days	7/12 (58.3)	0/12 (0)	0/7 (0)
14 days or more	4/10 (40)	0/10 (0)	0/4 (0)
Since positive RT-PCR test	Asymptomatic cases only; n (%)
0–5 days	6/6 (100)	3/6 (50)	3/6 (50)
6–9 days	3/4 (75)	0/4 (0)	0/3 (0)
10 days or more	1/10 (10)	0/10 (0)	0/1 (0)

Source: Adapted from the National Institute of Infectious Diseases (NIID) and the Centers for Disease Control and Prevention within the National Center for Global Health and Medicine (NCGM/DCC).²⁵