Coronaviruses of Domestic Livestock and Poultry: Interspecies Transmission, Pathogenesis, and Immunity

Abstract

Like severe acute respiratory syndrome-coronavirus (SARS-CoV), the CoVs of domestic livestock and poultry cause primarily respiratory and/or enteric disease. These animal CoVs belong to each of the three established CoV groups, with two subgroups recognized for groups 1 (1a and 1b) and 2 (2a and 2b). The swine enteric CoVs, porcine epidemic diarrhea virus (PEDV) and transmissible gastroenteritis virus (TGEV), and the spike protein (S protein) gene deletion respiratory mutant of TGEV, the porcine respiratory CoV (PRCV), belong to group 1. Bovine CoV (BCoV), wild-ruminant CoVs, and swine hemagglutinating encephalomyelitis virus (HEV) belong to CoV subgroup 2a along with canine respiratory CoV and human CoVs OC43 and HKU1. Similarly, the recently discovered SARS-CoVs that are associated with both respiratory and enteric infections in humans and animals belong to a new CoV subgroup, 2b. Avian CoVs are the exclusive members of CoV group 3. They cause respiratory and enteric infections, but some strains of the chicken CoV, infectious bronchitis virus (IBV), also cause nephritis and infections of the reproductive tract. This chapter focuses on representative CoVs of livestock and poultry from each of these three groups, with emphasis on the respiratory and enteric CoV infections and analogies to SARS-CoV. It provides insights into comparative aspects of transmission, pathogenesis, and immunity for these animal CoVs.