Table 1.

Description of parameter and their values. See the Supplementary Text for discussions of choice of parameter values.

Parameters	Description	Value	Ranges used in uncertainty analysis	References
$r$	Exponential growth rate	Estimated from data	0.1–0.35 /day
$I_0^{\ast }$	$I_0^{\ast }$is the number of total infected individual at time 0 (Jan. 20)	Estimated from data	0.0001–10 on a log scale
$\theta$	detection probability	Estimated from data	0.001–1 on a log scale
$\beta$	Infectivity in the SEIR model	Calculated from $r$		See Supplementary Text
$1/k$	The mean latent period, i.e. from infection to becoming infectious	3 days	3–4 days	He et al., 2020, Lauer et al., 2020, Sanche et al., 2020
$1/g$	The mean duration from infection to case confirmation	12 days	10–14 days	Ng et al., 2020, Sanche et al., 2020
$m$	Shape parameter for the duration from infection to symptom onset	3	2–4	Sanche et al. (2020)
$n$	Shape parameter for the duration from symptom onset to death.	4	3–5	Sanche et al. (2020)
$1/d$	Mean duration from infection to death	21.5 days	20.5–23.5 days	Sanche et al., 2020, Zhou et al., 2020
$X$	Infection fatality ratio	0.01	0.004–0.014	Dorigatti et al., 2020, Wu et al., 2020b