Emergence of virulent pseudorabies virus infection in northern China

Abstract

Our investigation was conducted in order to verify a recent severe epidemic at several swine farms in northern China that indicated a newly emerging disease. Evidence confirmed that the epidemic was caused by a virulent Pseudorabies virus infection in swine herds.

Keywords: Northern China; fatal infection; pseudorabies virus; swine.

Fig. 1

Regions of pseudorabies virus (PRV) outbreak in China. The provinces or autonomous cities affected are indicated in pink. Regions marked with black triangles indicate areas showing positive PRV results as detected by enzyme-linked immunosorbent assay and polymerase chain reaction analyses.

Fig. 2

Severe damage to multiple organs in experimental, infected piglets by postmortem and histopathological examinations. (A) Lung necrosis (arrows). (B) Liver with yellowish white spots indicating necrosis or hemorrhage. (C) Spleen infarct (arrow). (D) Kidney with bleeding spots. (E) Hemorrhagic lymph node. (F) Tonsil necrosis (arrows). (G) Slight encephalic edema. (H) Alveolar ducts and terminal bronchiolar cavities filled with cellular and serous exudates. (I) Swelling and degeneration of liver cells. (J) Splenic cord with unclear structure and reduced lymphocytes. (K) Swelling and disintegration of epithelial cells. (L) Reduced lymphoid nodules with irregular structures. (M) Epithelial cells filled with eosinophilic intranuclear inclusions. (N) Glial cells with neurons. (O) Breakage and disintegration of myocardial fibers. (P) Midgut gland atrophy. H&E stain, ×400.