Table 1.

Summary of the COVID-19 transmission and contact tracing in Ningbo from January 21 to March 6, 2020. The data are obtained from Chen et al. (2020).

	First generation	Close contacts	Second generation
			Symptomatic	Asymptomatic	Sub-total
Symptomatic	161	2001	107	19	126
Asymptomatic	30	146	3	3	6
Total	191	2147	110	22	132