Table 1.

Parameter Values

Parameter	Point Estimate	Lower Bound	Upper Bound	Source
Maximum simulation length (days)	365	—	—	Assumptiona
Days between donations	4	1	10	Assumptiona
Incidence (daily probability of infection)	10–3	10–4	10–2	Assumptionb
I 1 duration (days)	2	1	4	[11, 12, 16, 17]
I 2 duration (days)	5	3	10	[11, 12, 16, 17]
R 1 duration (days)	15	10	30	[11, 12, 16–19]
Probability that an infected donor is asymptomatic	0.40	0.10	0.70	[9]
Probability that an infected donor sheds virus in stool	0.50	0.33	0.66	[10, 13, 16, 17]
Days of donations rejected before development of symptoms	14	—	—	Assumptiona
Days between serology tests	60	—	—	Assumptiona
Serology test sensitivity	0.75	0.65	0.90	[20–22]
Serology test specificity	0.98	0.90	0.99	[21, 22]
Days between swab tests	14	—	—	Assumptiona
Swab test sensitivity	0.75	0.50	0.98	[23, 24]
Swab test specificity	0.95	0.90	0.99	[24]
Stool test sensitivity	0.80	0.50	0.99	Assumptionc
Stool test specificity	0.99	0.95	0.99	Assumptionc

NOTES: See Supplemental Table 1 for a summary of the meanings of the I₁, I₂, R₁, and R₂ categories. The lower and upper bounds represent the bounds of uniform distributions used when drawing random parameter values in the sensitivity analysis.

^aInformed by operations at a large stool bank [4].

^bThe point estimate of 10^–4 corresponds to 35 000 daily cases in a population of 350 million, approximating the US average in early April 2020.

^cInformed by an assay being implemented at a large stool bank.