Emerging and re-emerging coronaviruses in pigs

Area of Science:

• Veterinary Virology
• Infectious Diseases
• Animal Health

Background:

• Porcine epidemic diarrhea virus (PEDV), porcine deltacoronavirus (PDCoV), and swine acute diarrhea syndrome-coronavirus (SADS-CoV) are significant emerging/reemerging coronaviruses (CoVs) affecting swine health.
• These viruses cause acute gastroenteritis in neonatal piglets, leading to substantial economic losses in the swine industry.

Purpose of the Study:

• To summarize the current understanding of PEDV, PDCoV, and SADS-CoV, focusing on their origins, clinical manifestations, pathogenesis, and immunity.
• To highlight the need for targeted disease prevention and control strategies for these distinct viral threats.

Main Methods:

• Review of existing literature on PEDV, PDCoV, and SADS-CoV.
• Comparative analysis of sequence data, clinical signs, pathogenesis, and immunological responses.

Main Results:

• Sequence analyses suggest zoonotic origins for these CoVs, with PEDV and SADS-CoV potentially originating from bats and PDCoV from sparrows, underscoring interspecies transmission.
• All three viruses induce similar clinical signs and pathogenesis, characterized by intestinal epithelial cell necrosis, villous atrophy, malabsorptive diarrhea, vomiting, dehydration, and potential mortality in piglets.
• Natural infection elicits virus-specific protective immunity, but there is a notable absence of cross-protection among PEDV, PDCoV, and SADS-CoV.

Conclusions:

• Strict biosecurity measures are essential for managing these swine coronaviruses.
• The lack of cross-protection necessitates the development and implementation of individual vaccines for PEDV, PDCoV, and SADS-CoV to effectively prevent and control diseases in neonatal piglets.