2007年华北地区H3N8亚型马流感病毒的分离与鉴定

Isolation and Identification of Equine Influenza Virus Subtype H3N8 causing an outbreak in Northern China in 2007

2007年10月,华北地区某赛马场的马同时发生了以发烧、流水样鼻汁或脓性分泌物、咳嗽等临床症状为主的疾病,疑似马流行性感冒。采集患病赛马的鼻腔分泌物,发病期和发病后14d血清,经鸡胚接种法分离病毒,并用鸡红细胞血凝抑制试验(HI)、神经氨酸酶抑制试验(NI)、病毒回归试验、血清学检测和基因序列分析对分离的病毒进行了系统鉴定。结果表明分离的毒株(A/equine/Huabei/1/2007(H3N8)为马源H3N8亚型马流感病毒,基因型属于美洲分支。我们通过动物回归感染试验建立起分离毒株的实验感染模型。

In October 2007,an outbreak of severe respiratory disease with the developing clinical symptoms such as depression,anorexia,dry cough,high fever and mucopurulent nasal discharge occurred in race horses in Northern China.We took the samples of nasal discharge and paired sera and examined the presence of equine influenza virus and autibody.Embryonated SPF eggs were used for virus inoculation from nasopharyngeal swabs,viral growth was monitored by haemagglutination assay （HA） and the isolate was characterized by haemagglutination inhibition （HI） and neuraminidase inhibition （NI） assay.Four Mongolia horses as experimental animals were inoculated with the isolate for pathogenic experiment and the nucleotide of isolate was sequenced for sequence comparison.Serological test was also done for H3N8 subtype HI antibody in the serum samples.Results indicated that an influenza virus,A/equine/Huabei/1/2007（H3N8）,was isolated from horses with an acute respiratory infection,phylogenetic analyses of isolate indicated that each of 8 gene sequences are of equine origin and belong to one of the Americans cluster.The data of epidemiology revealed that H3N8 subtype equine influenza occurred in Northern China and experimental model of isolates was established successfully.