Table 2. Statistics and parameter ratios inferred from the model.

Statistic	Model parameter	Maximum likelihood estimate	Confidence interval
Force of community-based infection per community case	k	1.95 × 10−7	[1.49 × 10−7, 2.39 × 10−7]
Force of direct infection per HCW day (green ward)	g	2.53 × 10−4	[0, 1.10 × 10−3]
Force of direct infection per HCW day (red ward, pre-FFP3)	r 1	7.97 × 10−3	[3.65 × 10−3, 1.40 × 10−2]
Force of direct infection per ward day (red ward, post-FFP3)	r 2	6.84 × 10−10	[0, 3.38 × 10−3]
Relative direct risk on red wards post- versus pre-FFP3	r2/r1	0.00	[0, 0.478]
Relative direct risk on red ward versus green ward pre-FFP3	r1/g	31.47	[5.92, ∞)
Relative direct risk on red ward versus green ward post-FFP3	r2/g	0.00	[0, ∞)

FFP3, filtering face piece 3; HCW, healthcare worker.