Emerging and re-emerging coronaviruses in pigs

Graphical abstract

Highlights

• •

  Three coronaviruses are emerging/reemerging in pigs.

• •

  The three porcine coronaviruses may have originated from other species.

• •

  The clinical signs and pathogenesis of the three viruses are similar.

• •

  No cross-protection among the three porcine coronaviruses.

• •

  Individual vaccines are needed for each virus for disease prevention and control.

Abstract

Porcine epidemic diarrhea virus (PEDV), porcine deltacoronavirus (PDCoV), and swine acute diarrhea syndrome-coronavirus (SADS-CoV) are emerging/reemerging coronaviruses (CoVs). They cause acute gastroenteritis in neonatal piglets. Sequence analyses suggest that PEDV and SADS-CoV may have originated from bat CoVs and PDCoV from a sparrow CoV, reaffirming the interspecies transmission of CoVs. The clinical signs and pathogenesis of the three viruses are similar. Necrosis of infected intestinal epithelial cells occurs, causing villous atrophy that results in malabsorptive diarrhea. The severe diarrhea and vomiting may lead to dehydration and death of piglets. Natural infection induces protective immunity, but there is no cross-protection among the three viruses. Besides strict biosecurity measures, individual vaccines are needed for each virus for disease prevention and control.