A persistent epidemic of porcine epidemic diarrhoea virus infection by serological survey of commercial pig farms in northern Vietnam

Table 3 Proportion of PEDV seropositive farms based on age, breed groups and farm size

	Criteria	No. of PEDV seropositive farms/No. of examined farms
Age	18–23 weeks	5/5
	24–30 weeks	14/14
	Over 31 weeks	10/11
Breed	LYD	16/16
Breed	LY	13/14
Farm size (no. of pigs)	Less than 1000	6/6
	1001–1300	9/9
	Over 1301	14/15

ISSN: 1746-6148