. 2020 May 26;99(8):4052–4064. doi: 10.1016/j.psj.2020.04.025

Table 4.

Transmission coefficients (β, 95% CI) for experiments 2 and 3, using an SI model, for the basic model (assuming I-birds start excreting at the moment of the first positive cloaca swab) and the alternative model (assuming I-birds start excreting half an interval before the first positive cloaca swab).

Transmission coefficient (β, 95% CI)
	Basic model			Alternative model
	Model 1	Model 2	Model 3	Model 1	Model 2	Model 3
	(day⁻¹)	(day⁻²)	(cfu × day)⁻¹	(day⁻¹)	(day⁻²)	(cfu × day)⁻¹
Control	2.93 (1.38–5.40)	0.40 (0.19–0.76)	0.31 (0.10–0.57)	2.19 (1.09–3.91)	0.27 (0.13–0.49)	0.31 (0.10–0.57)
CEP	4.08 (0.76–19.43)	0.30 (0.05–1.48)	0.12 (0.15–0.56)∗	2.57 (0.51–11.47)	0.19 (0.04–0.87)	0.12 (0.15–0.56)∗
SYN	2.22 (0.46–9.96)	0.12 (0.02–0.57)∗	0.14 (0.02–0.63)∗∗	1.58 (0.35–6.57)	0.09 (0.02–0.40)∗	0.14 (0.02–0.63)∗∗
AIC	82.5	87.8	102.0	78.7	86.8	102.0

Expected number of cases (C) in model 1: $E (C) = S (1 - e^{- β_{d i r e c t} \times \frac{I}{N} \times Δ t})$ , model 2: $E (C) = S (1 - e^{- β_{t i m e} \times Σexcrhours \times Δ t}),$ and model 3: $E (C) = S (1 - e^{- β_{c o n c e n t r a t i o n} \times Σexcrconcentration \times Δ t}) .$ In model 3, cumulative excretion (cfu/g feces) is independent of the number of I-birds and is therefore independent of the assumption regarding the start of excretion.

Statistically different transmission coefficients compared to the control group: ∗P < 0.05, ∗∗P < 0.10.

Abbreviations: AIC, Akaike Information Criterion; CEP, competitive exclusion product; I-birds, infectious birds; SI model, susceptible infectious model; SYN, selection of pre- and probiotics.