2013～2017年鸡传染性支气管炎病毒分子流行病学分析

Molecular Epidemiology Analysis on Infectious Bronchitis Viruses Circulated in China during 2013 to 2017

研究从2013~2017年来自全国17个省/市/区优质鸡病料中分离鉴定出390株鸡传染性支气管炎病毒(Infectious bronchitis virus,IBV),按发病季节、发病日龄、分离地域、临床特征、基因型等信息进行统计分析。结果显示:分离株主要分离自冬春季节,集中于华东、华南和华中等家禽养殖密集区域,且发病日龄主要在10~40日龄,临床上表现为肾型、呼吸性和产蛋异常型;除3株为变异株外,387株聚类于7个进化分支,即7个基因型;其中QX型为主要的优势基因型,占分离毒株的55%,但其他进化分支毒株和变异毒株仍然占有一定的比例。IBV暴发以养禽密集高的地区为主,且冬春季节和40日龄以内的雏鸡是鸡传染性支气管炎防控的关键时期。

A total of 390 infectious bronchitis virus（IBV） strains were isolated from suspected samples of quality chickens provided by 17 regions during 2013 to 2017.The prevalence of IBV isolates was analyzed according to the epidemical season,age,area,clinical feature and genotype.As a result,the IBV strains were mainly isolated from 10-to 40-day-age chickens in East China,Southern China and Central China in the winter and spring.The main clinical symptoms caused by IBV isolates were kidney swelling,respiratory symptoms or abnormal egg.Among the 390 strains,3 isolates were variant,and other 387 strains belonged to 7 traditional genotypes.The QX-type IBV strains were still the dominant genotype in China,which accounted for 55%.However,other genotypes of IBV strains also still accounted for a certain proportion.In conclusion,this study suggested the control of IBV should focus on the chickens between10-to 40-day-age in spring and winter,especially in high-density breeding areas.