1例兔出血症病毒2型感染疫情的诊断

Diagnosis of a Rabbit Hemorrhagic Virus Type 2 Infection Epidemic

旨在了解河南疑似兔出血症病毒2型(RHDV2)的感染情况,并对RHDV2的致病性进行初步分析。本研究采集病死兔的肝组织,利用微量血凝试验、RT-PCR扩增及测序、VP60基因系统进化树分析和动物回归试验进行病原鉴定。微量血凝试验结果显示,组织样本悬液能够凝集人“O”型血红细胞;RT-PCR扩增、测序及序列分析结果显示,检测到RHDV2特异性条带,片段大小为829 bp;系统进化树分析结果发现,分离的病毒与我国四川发现的首例RHDV2毒株SC2020/04的VP60基因相似性高达98.2%;临床病例的剖检显示病死兔胸腺、气管、肺、肝、脾、肾等实质性器官出血较为严重;动物回归试验发现攻毒组家兔死亡率为100%,平均死亡时间为65.8 h,RT-PCR扩增均检测到RHDV2特异性条带。本研究首次在河南兔场检测到RHDV2,为RHDV2的防控提供了科学参考。

This study aimed to understand the infection situation of suspected rabbit hemorrhagic virus type 2(RHDV2)in Henan province,and preliminarily analyze the pathogenicity of RHDV2.The liver tissues of dead rabbits were collected,then the microblood coagulation assays,RT-PCR amplification and sequencing,VP60 gene phylogenetic tree analysis and animal regression test were conducted to identify the pathogen.The results of the microblood coagulation assay showed that the tissue sample suspension were able to produce a lect reaction with the human type"O"red blood cells;RT-PCR showed the detection of RHDV2-specific bands,the fragment size was 829 bp;Results of the phylogenetic tree analysis showed that the VP60 gene similarity was as high as 98.2%between the isolated virus and the first RHDV2 strain SC2020/04 found in Sichuan;The autopsy of clinical cases showed that the bleeding of thymus,trachea,lung,liver,spleen,kidney and other substantial organs was more serious;Animal regression test showed that the mortality rate of rabbits was 100%and the average death time was 65.8 h after challenge test,and the specific bands of RHDV2 were detected by RT-PCR amplification.In conclusion,the RHDV2 virus was detected for the first time in the rabbit field in Henan Province,which provided a scientific reference for the scientific and reasonable prevention and control of RHDV2.