Date Full Report Received

05/08/2015

Date Abstract Report Received

05/08/2015

Investigation

Institution:
Primary Investigator:

Porcine epidemic diarrhea virus (PEDV) and porcine enteric deltacoronavirus (PdCV) emerged recently in the United States and caused significant economic loss in the swine industry. Currently, the minimum in vivo viral infectious doses for PEDV and PdCV are not known. This information is important for the determination of infectious virus loads and for assessing feeds/environments as sources of infectious virus. The objective of this proposal is to identify the minimal titratable infectious dose of PEDV and PdCV in gnotobiotic piglets. Ten-fold dilutions (106, 104, 103, 102, 101 PFU) of PEDV and PdCV were performed and orally inoculated into each piglet in each group of 10-day-o

ld gnotobiotic piglets (n=5). For PEDV, inoculation doses of 106, 104, 103, and 102 PFU/piglet caused severe clinical signs (profuse watery diarrhea, vomiting, and dehydration) and gross and histologic lesions in small intestine. Piglets inoculated with 101 PFU of PEDV caused no to mild clinical signs and histologic lesions in small intestine. For PdCV, doses above 103 PFU per piglets caused severe clinical signs and pathological lesions whereas no to mild lesions observed for piglets inoculated with 102 PFU of PdCV. Thus, under our experimental conditions, the minimal infectious dose for PEDV and PdCV in gnotobiotic piglets is 101 PFU and 102 PFU, respectively. The finding that low infectious particles were sufficient to cause an infection in piglets highlights the need to develop effective measures to ensure complete inactivation of PEDV and PdCV in farm and environment.