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

Samples from 32 pig farms in central and southern Taiwan from December 2013 through January 2014 were submitted to the animal hospital of National Pingtung University of Science and Technology. All of the pig farms had similar disease histories, clinical signs and lesions, including the presence of a sudden outbreak and rapid spread in farms, high mortality in young pigs and diseases affecting animals of all age, notably, vomiting and diarrhea. Piglets under 2 weeks of age showed severe vomiting and watery yellowish diarrhea with morbidity and mortality ranging from 80 to 100% and 90 to 100%, respectively. However, sows, gilt, finishing, growing and nursery pigs only developed appetite loss, anorexia and soft feces for 3-7 days with no mortality during this outbreak. The infected suckling pigs showed different degrees of weight loss and dehydration. Thinned and distended small intestine walls with watery yellowish contents were recorded during necropsy. Microscopically, marked enterocyte exfoliation and vacuolation consistent with villi atrophy and blunt were observed in the jejunum and ileum sections. Additionally, the clinical specimens were collected and tested for rotavirus [3] , transmissible gastroenteritis virus [4] and porcine epidemic diarrhea virus [5] . All of the specimens were negative for rotavirus and transmissible gastroenteritis virus. A total of 68 samples from 25 pig farms were confirmed as positive for PEDV by reverse transcription PCR, and the partial S gene of PEDV was further analyzed [5] . The year of sampling, age and clinical history of each sampled pig are summarized in Table 1 .