Prevalence and pathologic study of porcine epidemic diarrhea in Jeju

ABSTRACT

From April 2014 to September 2015, 153 piglets from 52 farms in Jeju were diagnosed with porcine epidemic diarrhea (PED). The major PED cases were focused on suckling piglets (144 piglets, 94.1%), particularly in 1-7-day-old piglets. Histopathologically, severe villous atrophy was observed in the small intestine, especially in the jejunum and ileum. The mean villous height to crypt depth ratios of the jejunum and ileum were 1.41 and 1.51, respectively. The major histopathologic findings of the small intestine were cytoplasmic vacuolation, cuboidalization, squamation, and exfoliation of the mucosal enterocytes in the villi. The cytoplasmic vacuolations in the enterocytes were the most prevalent lesions in the small intestine and were more severe in the ileum than in the jejunum. According to immunohistochemistry methods, the PED virus (PEDV) antigens were presented in the cytoplasms of the enterocytes, and were distributed more prevalently in the ileum than in the jejunum. PEDV antigens were also detected in the colon of 29 piglets (19.5%). Sequence comparison and phylogenetic analysis indicated that 12 PEDV had more than a 98.9% homology with each other. These PEDV strains were highly homologous with the genogroup 2 North American group.