2016—2019年我国Ⅰ类新城疫病原学监测与遗传进化分析

Pathogenic Surveillance and Phylogenetic Analysis on Class Ⅰ Newcastle Disease Virus during 2016 to 2019 in China

为掌握我国Ⅰ类新城疫病毒(Newcastle disease virus,NDV)的分布及分子演化特征,2016—2019年,随机从国内23个省(自治区、直辖市)998个采样点,采集家禽口咽/泄殖腔双拭子样本、野鸟粪便样本和环境样本共45 458份,通过病毒分离和RT-PCR鉴定,共分离到Ⅰ类NDV 558株。从时间分布看,2016—2019年Ⅰ类NDV分离率分别为0.95%、0.89%、1.88%和1.37%,有增高趋势;从地理分布看,我国16个省(自治区、直辖市)分离到Ⅰ类NDV,主要集中于华东、西南和西北地区;从场点分布看,活禽批发市场和农贸市场的Ⅰ类NDV阳性率明显高于养殖场和屠宰场;从宿主分布看,Ⅰ类NDV主要来源于鸡和鸭,少量来自鹅、鸽和环境样本;从基因型分布看,558株Ⅰ类NDV属于2个基因亚型,其中1.1.2亚型为近年来我国流行的主要基因亚型。研究表明,我国Ⅰ类NDV污染面广,宿主范围广泛,且存在2种基因亚型。研究提示,应加强Ⅰ类NDV的免疫、监测,同时加强饲养管理,提高家禽抵抗力,降低病毒基因变异致毒力增强的风险。本研究为我国科学防控新城疫提供了参考数据。

In order to study the distribution and molecular evolution characteristics of class Ⅰ Newcastle disease virus(NDV)in China,a total of 45 458 samples including avian oropharynx/cloacal swabs,wild bird feces and environmental samples were randomly collected from 998 sampling sites in 23 provinces(autonomous regions and municipalities)from 2016 to 2019,and 558 strains of class Ⅰ NDV were isolated through virus isolation and RT-PCR. For time distribution,the isolation rates from 2016 to 2019 were 0.95%,0.89%,1.88% and 1.37%,respectively,and tended to increase;for geographical distribution,such NDV strains were isolated from 16 provinces(autonomous regions and municipalities),particularly in East,Southwest and Northwest China;for farms/premises,the positive rate of NDV in live poultry markets and agricultural markets was obviously higher than that in farms and slaughterhouses;for host distribution,the NDV strains were mainly derived from chickens and ducks,and fewer from geese,pigeons and environment;and for genotype distribution,the isolated strains fell into two genotypes,in which,1.1.2 subtype was predominant in China in recent years. It was concluded that the NDV was widely spread with a large range of hosts and two genotypes. Therefore,the vaccination and surveillance against NDV should be strengthened,meanwhile,feeding management should be enhanced so as to improve relevant resistance of poultry and reduce the risk of increased virulence produced by virus genetic variation. In view of the above,some reference data were provided for scientific prevention and control of NDV in China.