Light Microscopy and Ultrahistology of Intestinal Changes in Pigs Infected with Epizootic Diarrhoea Virus (EVD): Comparison with Transmissible Gastroenteritis (TGE) Virus and Porcine Rotavirus Infections

Abstract

Light microscopic and ultrahistological changes were investigated in the intestines of piglets naturally and experimentally infected with epizootic viral diarrhea (EVD) virus and compared to those which occur during intestinal transmissible gastroenteritis (TGE) and rotavirus infections. The course of the EVD virus infection is comparable to that of TGE. Villous atrophy develops throughout the jejunum and ileum. It differs from rotavirus infection in this respect. The intestinal ultrastructure following EVD virus infection resembles that of TGE and other enteropathogenic coronaviruses. Virus replication was observed mainly in enterocytes located on the lateral walls of the villi extending to the villus/crypt border, and occasionally virus-infected cells were demonstrated in or near the Lieberkuhn''s crypts. EVD virus was also demonstrated in macrophages of the intestinal lamina propria and in regional lymph nodes phagocytes.