Isolation and characterization of a low pathogenic duck hepatitis A virus 3 from South Korea.

The D11-JW-018 strain of duck hepatitis A virus (DHAV) was isolated from 7-day-old ducklings in Kyeonggi province, South Korea with no clinical signs of typical hepatitis. Phylogenetic analyzed of whole genome showed that D11-JW-018 strain was belonged to DHAV-3 genotype. The pathogenicity of the D11-JW-018 strain in 1-, 7-, 14-, and 21-day-old ducklings was examined. Mortality of D11-JW-018 strain was lower than DRL-62 (DHAV-1) age-dependent but incubation period was longer in 1-day-old ducklings. Unlike DRL-62 strain infection, D11-JW-018 strain induced only liver discoloration without hemorrhagic mottling and lymphocyte infiltration and bile duct hyperplasia in histological lesion. The D11-JW-018 strain was detected only in the heart, liver, spleen, gall bladder, pancreas, and kidney among 12 organs in infected 1-day-old ducklings. Serum biochemical analyses revealed a significant difference in aspartate transaminase and alanine transaminase between the D11-JW-018 strain-infected ducklings and those infected with the DRL-62 strain (P<0.05). We identified the D11-JW-018 strain in South Korean ducklings and provide the characteristics of DHAV-3.