福建省番鸭细小病毒病流行病学及病原研究

Epidemiology and Pathogen of Muscovy Duck Parvovirus Disease in Fujian Province

从福建省番鸭主要饲养区共收集临床疑似番鸭细小病毒(Muscovy duck parvovirus,MDPV)病病料65份,进行病原学检测、病原分离、动物回归试验、免疫攻毒试验、基因片段序列分析,旨在研究福建省番鸭细小病毒病流行情况及病毒遗传变异状况。结果显示:仅有10份为MDPV感染,占比为15.2%;其余均为其他病原或两种病原混合感染。MDPV一年四季均能发生,但主要以冬春季节多发(占80%)。从分离的10株MDPV来看,分离株均能致死番鸭胚,番鸭感染MDPV分离株后发病率为80%~100%,死亡率为40%~60%,与1985年分离的MDPV-P株特性相似。1日龄番鸭免疫番鸭细小病毒病活疫苗后,7日龄进行分离株的攻毒,未见发病和死亡现象。基因进化树显示10株分离株与MDPV-P株属于同一分支。基于2018年流行的MDPV毒株与1985年MDPV-P株致病性、抗原性和基因序列特性相似,无明显变化,可使用番鸭细小病毒病活疫苗进行免疫可有效防控该病。

A total of 65 clinically suspected cases of Muscovy duck parvovirus(MDPV) disease were collected from the main breeding areas of Muscovy ducks in Fujian province. Etiological detection, pathogen isolation animal regression test, MDPV virus infection and immune challenge, and gene fragment sequence analysis were carried out to study the epidemic situation and genetic variation of MDPV in Fujian province. The results showed that only 10 cases were MDPV infection, accounting for 15.2%. The rest were infected by other pathogens or a mixture of two pathogens. The disease could occur in all seasons of the year, but mainly in winter and spring(80%). According to the10 isolates of MDPV, the isolated virus could all kill Muscovy duck embryos. The morbidity and mortality after muscovy duck were infected with the isolated strains were 80% to 100% and 40% to 60%, respectively, which was similar to MDPV-P strain isolated in 1985. After 1-day-age Muscovy ducks were immunized with live vaccine of Muscovy duck parvovirus disease, 7-day-age Muscovy ducks were inoculated with the isolated strain, and no morbidity or mortality was found. The phylogenetic tree showed that 10 isolates belonged to the same branch as MDPV-P strain. Therefore, the pathogenicity, antigenicity and gene sequence characteristics of prevalent MDPV in 2018 were similar to those of MDPV-P strain in 1985, and there was no obvious change. Vaccination with muscovy duck parvovirus live vaccine could effectively prevent and control the disease.