Isolation and Identification of Duck Herpesvirus Type II (Named tentatively)

A new infectious disease of ducks with conspicuous symptoms of darkened feather follicle and feather dropping and with hemorrhages in liver,pancreas,spleen and intestine occurred in Fujian,Zhejian and Guangdong provinces since 1990.This disease was named tentatively as duck hemorrhagic disease(DHD).A isolation containing two kinds of viral particles with 30_40nm in diameter was gained from the typical dead ducks.A pure viral strain was isolated by serial neutralization of postive serum against duck hepatitis virus type Ⅰ,and named as duck hemorrhagic disease virus(DHDV).It was sensitive to acid(PH3.0),alkali(PH11),heat(56℃)and chloroform.Many spherical particles with envelope and 80_120nm in diameter were scanned by electron microscopy.Agarose gelelectrophoresis analysis showed that its nuclei acid is double_strand DNA.The mortalities of embryonated poultry eggs (including muscovy duck embryo,goose embryo,semi_muscovy embryo,shanma duck embryo,pekin duck embryo and SPF chicken embryo)inoculated with it were 100% ,100%,60%,78.3%,82.1% and 0,respectively.It had no hemagglutination activity and no serological correlations with duck hepatitis virus type Ⅰ,muscovy duckling parvovirus,gosling parvovirus and duck plague virus.It was categorized into herpesviridae and named tentatively as duck herpesvirus type Ⅱ because of serological difference from duck plague virus (duck herpesvirus type Ⅰ).This is first reported.