Table 1.

Summary of the animal age groups included in the study and their seroprevalence against PToV

Age	No.of sera	Positive	Prevalence (95%CI)a	O.D.492 ± s.d.b
Sows	1388	1382	99.6% (99.0; 99.8)	1.03 ± 0.36
20 weeks	671	664	98.9% (97.8; 99.5)	0.85 ± 0.33
15 weeks	127	127	100.0% (96.5; 100.0)	1.02 ± 0.24
11 weeks	84	81	96.4% (89.6; 99.2)	0.73 ± 0.34
7 weeks	189	161	85.2% (79.4; 89.6)	0.52 ± 0.17
5 weeks	40	37	92.5% (79.4; 98.1)	0.59 ± 0.31
3 weeks	165	98	59.4% (51.8; 66.6)	0.45 ± 0.16
Total	2664	2550	95.7% (95.0; 96.5)

^a CI, exact binomial confidence interval. ^b Mean O.D. ₄₉₂ values and their corresponding standard deviation.