Table 3. PRV-positive rate in pigs sampled in Shandong province from 2015 to 2018.

Year	Sample numbers	Positive numbers	PRV-positive rate	OR	95% CI
2015	196	31	15.8%	1 (ref.)
2016	395	110	27.8%	2.054	1.320–3.197
2017	556	60	10.8%	0.644	0.403–1.028
2018	491	56	11.4%	0.685	0.427–1.101
Total	1,638	257	15.7%

PRV = pseudorabies virus; OR = odds ratio; CI = confidence interval.