Table 2. The prevalence of antibodies against HEV among pigs in 2011–2013, Guangdong Province, China.

	Serum sample		Univariate analysis
	Positive/Total (n)	Positive rate (%)	ORa (95% CI b)	X2 c	P value
Different swine farm
Nursery pig (<4 wks)	46/133	34.59	refd
Growing pig (>4 wk-6 mos)	52/80	65.00	3.51(1.95–6.33)	17.40	<104
Sow (>7 mos)	208/286	72.72	5.04(3.27–7.77)	53.74	<104
Boar (>7 mos)	57/62	91.93	21.56(9.47–49.10)	53.53	<104
Sow
Pre-farrowing sow	58/96	60.42	ref
Multiparous sow	150/190	78.95	2.46(1.45–4.18)	10.13	<0.01

a: OR, odds ratio;

b: 95%CI, 95%confidence interval;

c: X², Chi-Square Test;

d: ref, reference.