鸭副粘病毒强毒株的分离和鉴定

Isolation and Identification of High Pathogenic Duck Paramyxovirus

采用鸡胚接种法从安徽凤阳某患病肉鸭群中分离到一株病毒。该毒株对鸡红细胞具有凝集性，并可被康复鸭鸭血清和ＮＤＶ阳性抗血清所抑制，而不能被禽流感标准阳性血清抑制，结合血清中和鸡胚接种试验。病毒回归试验和免疫防治效果的研究结果，确认为鸭副粘病毒。参照国际上规定的新城疫病毒毒力判定的标准及其方法，测定该分离株的鸡胚最小致死量平均死亡时间（ＭＤＴ）、１日龄鸡脑内接种致病指数（ＩＣＰＩ）和６周龄鸡静脉内接种致病指数（ＷＰＩ）分别为４８．９ｈ、１．８０和２．４５。表明该鸭副粘病毒分离株具有新城疫病毒（ＮＤＶ）速发型相类似的毒力，属强毒力毒株，并定名为ＷＦ００Ｄ株。

A new viral disease of duck was reported. the strain virus was isolated from infected duck's livers, spleens and pancreas in Fengyang Anhui Province using chicken embryos. The virus could agglutinate the chicken erythrocytes. The hemaagglutination of virus could be inhibited by the convalescent antiserum, the Newcastle disease virus(NDV) F48E9 strain antiserum, the antiserum of goose paramyxovirus type-I isolated by our laboratory respectivcly. But it could' t be inhibited by avian influenza virus(AIV) positive anti- serum. The HA titer ranged between 2~8 and 2~9. Artificial infection could cause up to 100% morbidity and 50% - 100% mortality in 10-day--old ducks, with almost the same clinical symptoms and pathological changes. The 30 - day - old chickens can also be infected with 100% morbidity and 100% mortality. The inactivated vaccine made from the isolated virus and the egg yolk antibodies from its hyperimmunized layers could give very good protection against the natural infection of ducks. The biological characteristics of the virus was determined by measuring the mean death time of chicken embryos(MDT), the intracerebral pathogenicity index in day - old chicks (ICPI) and the intravenous pathogenicity index in 6-week - old chickens(IVPI). The MDT.ICPI and IVPI were 48.9h. 1.8O and 2.45 respectively. The results indicated that the isolate was of high virulence like velogenic Newcastle disease virus(NDV) and named duck paramyxovirus WF00D strain.