Fecal shedding of a highly cell-culture-adapted porcine epidemic diarrhea virus after oral inoculation in pigs

Received: October 28, 2004 Accepted: January 26, 2005 Porcine epidemic diarrhea virus (PEDV), an enveloped, singlestranded RNA virus1,2 in the family Coronaviridae, causes severe diarrhea in swine. The main and only obvious clinical sign of porcine epidemic diarrhea (PED) is watery diarrhea. Mortality may be as high as 80%, but averages 50%.3,4 Piglets up to 1 week of age may die from dehydration after 3 to 4 days. In Europe, weaned pigs and even adult pigs have been severely affected, while disease in suckling pigs in the same herds was mild, even in the absence of immunity.5 The virus is transmitted in feces from infected pigs.6 Detection of PEDV antigen in feces after inoculation varies with virulence and inoculated dose.7 In a previous study, PEDV strain DR13 was isolated and serially passaged in Vero cell cultures.8 The highly adapted virus was differentiated from wild-type viruses by reverse transcriptase-polymerase chain reaction (RT-PCR) and restriction fragment length polymorphism (RFLP).8,9