Table 2. Detection of HEV antibodies in swine sera in Hebei province, China.

	Farm1	Farm2	Farm3	Farm4	Farm5	Total
Sera number	89	24	104	28	31	276
Positive number	46	13	59	12	27	157
Positive percentage	51.59%	54.17	56.73%	42.86%	87.10%	56.88%

Note: Farm1, farm2, farm3 and farm4 are large farms in which pigs were fed with feeder; Farm1 and farm2 were in Shijianzhuang province, and farm3 and farm4 in Baoding province; farm5 was a family-size farm in which pigs were fed with swill.