辽宁省锦州市动物园一起孔雀H7N9流感疫情的紧急流行病学调查

An Emergency Epidemiological Investigation on the Outbreak of Peacock H7N9 Influenza in Jinzhou Zoo of Liaoning Province

2019年3月18日,辽宁省锦州市动物园报告其饲养的孔雀接连两天出现急性发病死亡。经专家组现场临床诊断,市级、省级兽医实验室检测,诊断为疑似H7N9流感疫情;经国家禽流感参考实验室进行鸡胚接种分离病毒、亚型鉴定和基因测序分析,确诊为高致病性H7N9流感疫情。为追溯疫情的可能来源、分析疫情的扩散风险,继而提出针对性的防控建议,采用现场勘察、访谈、问卷调查等形式,结合实验室检测,对该起疫情进行了紧急流行病学调查。调查发现:该起疫情袭击率为4.5%(9/200),由迁徙候鸟带毒引入可能性较大;未及时开展免疫,导致抗体水平不达标是引起疫情暴发的内在因素。经过科学处置,疫情未发生扩散。本起疫情提示,必须扎实做好禽流感免疫相关工作,高度重视家禽饲养场以及其他场所观赏鸟类的免疫,确保筑牢免疫屏障,以降低疫情发生风险。

On March 18,2019,it was reported by Jinzhou Zoo of Liaoning Province that the peacocks died of an acute disease for two consecutive days.Then the epidemic was confirmed as an outbreak of suspected H7N9 influenza by field diagnosis of expert team and retesting of veterinary laboratories at municipal and provincial levels successively;at last,it was confirmed as H7N9 highly pathogenic influenza through embryo inoculation for virus isolation,subtype identification and gene sequencing analysis carried out by national avian influenza reference laboratory.In order to trace all possible sources of the outbreak,analyze the risk of spreading,an emergency epidemiological investigation was carried out by means of field investigation,interview and questionnaire survey and in combination with laboratory test.The results showed that the outbreak,with the attack rate of 4.5%(9/200),was more likely to be introduced by migratory birds,besides,the internal factor was the unqualified antibody level due to failure to carry out vaccination in time.The outbreak was controlled without any spreading after scientific response.In view of the above,it was suggested that avian influenza immunization should be well carried out,especially for the poultry farms and the ornamental birds in other premises,so as to build a strong foundation of immunization and to reduce the risk of outbreak.