Table 1.

Parameter estimates for COVID-19 in Ontario, Canada

Parameter		Definitions	Feb 26 to Mar 21	Feb 26 to Mar 25	Feb 26 to Mar 29	Feb 26 to Apr 13	Source
c		Contact rate	11.7905	11.5539	9.1586	–	Estimated
c(t)	$c_0$	Constant contact rate before $T_s$	–	–	–	10.0005	Estimated
	$r_1$	Exponential decreasing rate of contact rate	–	–	–	0.0632	Estimated
	$c_b$	Minimum contact rate after $T_s$	–	–	–	3.4999	Estimated
β		Probability of transmission per contact	0.1450	0.1450	0.1452	0.1438	Estimated
q		Quarantined rate of exposed individuals	0.0810	0.1479	0.1754	0.1003	Estimated
σ		Transition rate of exposed individuals to the infected class	1/5	1/5	1/5	1/5	[10]
λ		Rate at which the quarantined uninfected contacts were released into the wider community	1/14	1/14	1/14	1/14	[7]
ρ		Probability of having symptoms among infected individuals	0.6	0.6	0.7847	0.6201	Estimated
${\delta }_I$		Transition rate of symptomatic infected individuals to the quarantined infected class	0.1	0.1	0.1	–	Estimated
${\delta }_I(t)$	${\delta }_{I0}$	Constant transition rate of symptomatic infected individuals to the quarantined infected class before $T_s$	–	–	–	1/9.2	Data
	$r_2$	Exponential increasing rate of the detection rate	–	–	–	0.7174	Estimated
	${\delta }_{If}$	Fastest transition rate of symptomatic infected individuals to the quarantined infected class after $T_s$	–	–	–	0.5642	Estimated
${\delta }_q$		Transition rate of quarantined exposed individuals to the quarantined infected class	0.1	0.1	0.1	0.1	Estimated
${\gamma }_I$		Recovery rate of symptomatic infected individuals	0.2	0.2	0.1999	0.1830	Estimated
${\gamma }_A$		Recovery rate of asymptomatic infected individuals	0.139	0.139	0.139	0.139	[7]
${\gamma }_H$		Recovery rate of quarantined diagnosed individuals	0.2	0.2	0.2	0.2	[6]
α		Disease-induced death rate	0.008	0.008	0.008	0.008	[6]
θ		Modification factor of asymptomatic infectiousness	0.0429	0.0465	0.0308	0.0494	Estimated
$R_c$		Control reproduction number	3.2546	2.9720	2.8464	–	Estimated

Initial values	Definitions	Feb 26 to Mar 21	Feb 26 to Mar 25	Feb 26 to Mar 29	Feb 26 to Apr 13	Source
S(0)	Initial susceptible population	1.999 × 106	1.999 × 106	1.999 × 106	1.993 × 106	Estimated
E(0)	Initial exposed population	10	12	10	10	Estimated
I(0)	Initial symptomatic infected population	7.6	7	8.5	10	Estimated
A(0)	Initial asymptomatic infected population	15	24	23	24	Estimated
$S_q(0)$	Initial quarantined susceptible population	0	0	0	0	Data
$E_q(0)$	Initial quarantined exposed population	0	0	0	0	Data
D(0)	Initial quarantined diagnosed population	5	5	5	5	Data
R(0)	Initial recovered population	0	0	0	0	Data