Comparative Pathogenicity of Duck Hepatitis A Virus Type 1 and 3 Infections in South Korea

Abstract

Despite the impact of duck hepatitis virus type 1 (DHAV) as economically important and devastating pathogen in duck industry, there is a scarcity of data on the pathogenesis of DHAV. In this study, 1-day old ducklings were orally inoculated with DHAV-3 isolate (DHAV-3/duck-wt/KOR/Y02-1/2012) and DRL-62 strain as control virus in addition to mock-inoculated group. These strains induced the same clinical signs and gross lesions in virus-inoculated ducklings. The clinical signs appeared at HPI 24 and the mortalities were recorded by HPI 36. Histopatholoically, both strains induced the same characteristic liver lesions: hepatocyte necrosis, lymphoid cell infiltration in the portal triad and bile duct hyperplasia. Different microscopic lesions were also observed in extra-hepatic organs and tissues. By RT-PCR and nested PCR, viral RNA was detected in liver, spleen, brain, kidney, lung, heart, pancreas, bursa of Fabricious and thymus. An immunofluorescence assay confirmed virus antigen localization in these organs and tissues. Serum biochemical analysis revealed a significant hypoalbuminemia which reached the lowest level by HPI 24. These results indicated that DHAV-1 or 3 have a strong liver tropism and a pantropic effect with wide damage to various organs and tissues. The lesions of spleen, bursa of Fabricious and thymus indicated that the immune function might be affected by the DHAV infection. ©2019 PVJ. All rights reserved Key words: Albumin Duck hepatitis virus Histopathology IFA PCR To Cite This Article: Soliman M, Park JG and Park SI, 2019. Comparative pathogenicity of duck hepatitis a virus type 1 and 3 infections in south korea. Pak Vet J, 39(2): 271-277. http://dx.