鹅新发肾致病型星状病毒感染的流行动态及传播研究

Astrovirus infections are considered the cause of gastroenteritis in humans and many domestic animals. They have also been associated with extra-intestinal infections, such as duck hepatitis and chicken nephritis. Recently, outbreaks of visceral gout in gosling flocks were reported in goose-producing regions in China, with the mortality rate ranging from 15-30%. A genetically distinct astrovirus was isolated and a similar disease was reproduced by infecting the healthy goslings with the isolated virus via multiple inoculation routes. Our systematic studies demonstrated for the first time that the causative agent of the fatal gosling gout was a new genotype species of astrovirus. To elucidate the epizootic dynamics of the emerging astrovirus in goose populations, following experiments will be conducted in this project: i) evaluation of the age-related susceptibility of geese by experimental infection with the isolated astrovirus; ii) investigation of astrovirus prevalence and transmission within and between goose flocks by follow-up detection of the virus and antibody responses of geese; iii）analysis of the genomes and virulence of the astrovirus isolates obtained during the field investigation. Our results are expected to provide scientific epidemiological information for the future diagnosis and control of the disease.

星状病毒为单股正链RNA病毒，广泛存在于人类和动物中，除引起胃肠炎外，还可引起典型的非肠道感染，如鸡致死性肾炎、痛风和雏鸭肝炎等，给养殖业造成一定的经济损失。近年来，我国多个地区的商品鹅场雏鹅群频繁发生内脏痛风，死亡率为15%-30%不等。经过系统的病因学调查，本课题组从发病鹅组织样品中分离到1株星状病毒，并利用该分离株感染健康雏鹅复制了与临床病例相似的病症，确诊雏鹅痛风是由一种新型致肾病变型星状病毒感染所引起的新发传染病。为进一步了解该病的发生状况和流行特点，本项目拟通过临床调查，结合实验研究对我国主要养鹅地区商品鹅场的发病和流行状况进行跟踪采样和检测分析，调查并确定疾病的流行范围、不同日龄鹅对肾致病型星状病毒的易感性，比较不同毒株的遗传学及抗原差异等，系统阐述该新发传染的流行动态，为制定有效防控措施等提供科学依据。