US-Like Strain of Porcine Epidemic Diarrhea Virus Outbreaks in Taiwan, 2013–2014

LIN, Chao-Nan; CHUNG, Wen-Bin; CHANG, Shu-Wei; WEN, Chi-Chi; LIU, Hung; CHIEN, Chi-Hsien; CHIOU, Ming-Tang

Porcine epidemic diarrhea viruses (PEDVs) are enveloped viruses with a large, capped and polyadenylated RNA genome of approximately 28,000 nucleotides [6] . PEDVs belong to the genus Alphacoronavirus, family Coronaviridae and order Nidovirales. Other members of this subgroup include human coronavirus (HCoV) 229E, HCoV NL63 and Bats coronavirus 512/05 [8] . Although PEDV was first identified in Europe, it has become increasingly problematic in many Asian countries [6] and North America [7] . However, there is no retrospective study on the emergence of PEDV in Taiwan. Pigs of all ages can be affected and can exhibit degrees of diarrhea and loss of appetite, which vary according to age. In suckling piglets that exhibit watery diarrhea, dehydration with milk curd vomitus and thin-walled intestines with severe villus atrophy and congestion, PEDVs are associated with disease. The disease can progress to death within a few days. The outbreak is distinguished by a nearly 100% prevalence of illness among piglets after birth and death rates of 80-100%. Boars and sows with mild diarrhea, vomiting and anorexia for a few days were reported to recover within a week [6, 7] .