Table III.

Posterior estimates of true pig-level prevalence (%) and herd-level prevalence (%) of Toxoplasma gondii in Ontario 2001, 2003, and 2004 and for coefficients of random effect logistic regression model

Node	Mean	2.5 pa	Median	97.5 pa	Prior
Tests
Test sensitivity	85.28	73.73	85.79	93.94	Beta (44.5, 6.6)
Test specificity	99.88	99.75	99.89	99.96	Beta (159.1, 4.2)
Logistic regression model (LRM)
Intercept	−6.22	−7.17	−6.21	−5.35	N (0,1)
Presence of cats	0.23	−0.85	0.24	1.26	N (0,1)
Year 2003	−2.00	−3.36	−1.98	−0.75	N (0,1)
Year 2004	−1.47	−2.78	−1.45	−0.26	N (0,1)
Herd (random)	2.15e	1.68e	2.13e	2.73e	N [0, Gamma(1,25)]d
Prevalence
Pig true prevalence in 2001	1.69	1.22	1.67	2.25	(LRM)
Pig true prevalence in 2003	0.19	0.04	0.17	0.45	(LRM)
Pig true prevalence in 2004	0.33	0.10	0.31	0.69	(LRM)
Herdb prevalence in 2001	11.28	7.37	11.58	16.84	(LRM)
Herdb prevalence in 2003	0.52	0.00	0.00	2.50	(LRM)
Herdb prevalence in 2004	1.54	0.00	1.25	5.00	(LRM)
Herdc prevalence in 2001	5.84	3.16	6.32	8.42	(LRM)
Herdc prevalence in 2003	0.05	0.00	0.00	1.25	(LRM)
Herdc prevalence in 2004	0.33	0.00	0.00	1.25	(LRM)

N — Normal distribution; LRM — logistic regression model.

^ap — percentile.

^bBased on ≥ 1 as a herd cut-off.

^cBased on ≥ 2 as a herd cut-off.

^dSpecified in a form as required by WinBugs (as precision, not as standard deviation).

^eSpecified as standard deviation.