Vickery K, Cossart Y
Department of Infecrious Diseases, University of Sydney, NSW, Australia.
J Hepatol. 1996 Oct;25(4):504-9. doi: 10.1016/s0168-8278(96)80210-8.
BACKGROUND/AIMS: The immunological response of ducks to acute infection with duck hepatitis B virus (DHBV) has not been fully characterised. In this study the relationship between viral dose and the outcome of infection in immune competent 26-day-old ducks was examined.
Indirect ELISA assays were developed to detect the presence of antibody to DHB surface antigen and DHB core antigen. A DHBV serum pool was titrated in 1-day-old and 26-day-old ducklings.
The ID50 dose of the ducks injected at 26 days of age was found to be 1000 times that of the ducks injected on day of hatch. The antibody responses and serum DHBV DNA were followed in eight ducks inoculated with DHBV positive serum when 26 days of gene and in three ducks infected with DHBV on day of hatch. The three ducks infected on day of hatch were viraemic by day 7 and remained highly viraemic throughout the experimental period. In the older ducks, inoculation with 1000ID50 resulted in the development of chronic carriage, while inoculation with either 100 or 10ID50 doses resulted in acute infection with or without viraemia. These ducks were able to clear the infection from their circulation, but only 50% cleared DHBV from the liver within the experimental period. All infected ducks developed anti-core activity. Only non-viraemic ducks developed anti-surface activity.
DHBV infection can be established in immune competent adolescent ducks, with variable disease outcomes comparable to HBV infection in humans.
背景/目的：鸭对鸭乙型肝炎病毒（DHBV）急性感染的免疫反应尚未完全明确。本研究检测了免疫功能正常的26日龄鸭中病毒剂量与感染结果之间的关系。
开发间接ELISA检测法以检测DHB表面抗原和DHB核心抗原抗体的存在。用1日龄和26日龄雏鸭对DHBV血清库进行滴定。
发现26日龄注射鸭的半数感染量（ID50）是孵化日注射鸭的1000倍。对8只26日龄接种DHBV阳性血清的鸭和3只孵化日感染DHBV的鸭进行抗体反应和血清DHBV DNA跟踪检测。3只孵化日感染的鸭在第7天出现病毒血症，并在整个实验期间一直保持高病毒血症状态。在年龄较大的鸭中，接种1000ID50导致慢性携带，而接种100或10ID50剂量则导致急性感染，伴有或不伴有病毒血症。这些鸭能够从循环中清除感染，但在实验期内只有50%的鸭从肝脏中清除了DHBV。所有感染鸭均产生了抗核心活性。只有非病毒血症鸭产生了抗表面活性。
DHBV感染可在免疫功能正常的青春期鸭中建立，其疾病结局各异，与人类HBV感染相似。
