Pathological Characterization of an Outbreak of Porcine Reproductive and Respiratory Syndrome in Northern Vietnam

Publication date: Available online 7 January 2016 Source:Journal of Comparative Pathology Author(s): N.T. Huong Giang, N.T. Lan, N.H. Nam, T. Hirai, R. Yamaguchi In 2007, a highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) emerged in Vietnam and spread to nearly all regions of the country by 2010. Ten representative pigs of different age groups, infected naturally with HP-PRRSV in northern Vietnam in 2010, were used to characterize the pathological features of the infection. Infection was confirmed using reverse transcriptase polymerase chain reaction and viral isolation. The clinical signs and gross findings in these pigs included high fever (>40.2°C), red skin, blue ears, anorexia, respiratory distress, diarrhoea, haemorrhagic pleurisy and lymphadenopathy. Reproductive failure was the main clinical feature in sows. PRRSV infection-associated microscopical lung and lymph node lesions were observed frequently, regardless of age of the animals. Lung lesions were characterized by interstitial pneumonia and were occasionally associated with haemorrhage and fluid exudation following alveolar collapse. Lymph nodes exhibited characteristic haemorrhage and apoptosis, lymphocytic depletion and disorganization secondary to fibrosis and capillary formation. Haematoxylin and eosin staining or caspase-3 immunohistochemistry revealed apoptosis induction in various tissues and organs, particularly the lymph nodes and lungs. Primarily hae...
Source: Journal of Comparative Pathology - Category: Pathology Source Type: research