Hemagglutinating encephalomyelitis coronavirus infection in pigs, Argentina

Abstract

We describe an outbreak of vomiting, wasting, and encephalomyelitis syndrome in piglets in Argentina, caused by porcine hemagglutinating encephalomyelitis coronavirus (PHE-CoV) infection. Diagnosis was made by epidemiologic factors, pathologic features, immunohistochemistry, reverse transcription-PCR, and genomic sequencing. This study documents PHE-CoV infection in South America.

Figure 1

A) Nursery piglets showing clinical signs compatible with porcine hemagglutinating encephalomyelitis coronavirus (PHE-CoV). Nonaffected pigs of the same age are also shown. B) Muscle layer of stomach from affected piglet showing perivascular cuffing (arrow); hematoxylin-eosin stain, magnification ×100. C) Brainstem from affected piglet showing satellitosis (arrows) and gliosis; hematoxylin-eosin stain, magnification x400. D) Brainstem from affected piglet showing positive label of neuron perikarion (arrows); nitroblue-tetrazolium imunohistochemical stain, magnification x400.

Figure 2

Polyacrylamide gel and silver staining of reverse transcription–PCR products from brains of piglets infected with porcine hemagglutinating encephalomyelitis coronavirus. Amplicons of ≈250 bp were found in brain samples from pigs 6, 8, 9, and 11 days of age. Neg, negative control (water + mastermix); PK15, amplification of PK15 cells inoculated with brain and tonsil from affected piglet; AP, asymptomatic piglet; and Ladder, 50-bp Fermentas.