Biblioteca Digital

Although the original US porcine epidemic diarrhea virus (PEDV) was confirmed as highly virulent by multiple studies, the virulence of spike-insertion deletion (S-INDEL) PEDV strains is undefined. In this study, 3–4 day-old conventional suckling piglets were inoculated with S-INDEL PEDV Iowa106 (4 pig litters) to study its virulence. Two litters of age-matched piglets were inoculated with either the original US PEDV PC21A or mock as positive and negative controls, respectively. Subsequently, all pigs were challenged with the original US PEDV PC21A on 21–29 days post-inoculation (dpi) to assess cross-protection. All S-INDEL Iowa106- and the original US PC21A-inoculated piglets developed diarrhea. However, the severity of clinical signs, mortality (0–75%) and fecal PEDV RNA shedding titers varied among the four S-INDEL Iowa106-inoculated litters. Compared with the original PC21A, piglets euthanized/died acutely from S-INDEL Iowa106 infection had relatively milder villous atrophy, lower antigen scores and more limited intestinal infection. Two of four S-INDEL Iowa106-infected sows and the original PC21A-infected sow showed anorexia and watery diarrhea for 1–4 days. After the original PC21A challenge, a subset (13/16) of S-INDEL Iowa106-inoculated piglets developed diarrhea...