台灣豬場豬瘟疫苗施打前後之抗體表現和病毒RNA檢出之探討

Investigation of Antibody Performance and Presence of Viral RNA before and after Vaccination of Classical Swine Fever Vaccine Strain in Taiwan Pig Farms

馬尉真(Wei-Jhen Ma) ； 陳秋麟(Qiu-Lin Chen) ； 張志成(Chih-Cheng Chang)

《臺灣獸醫學雜誌》 36卷1期 (2010/03) Pp. 45-54

https://doi.org/10.7009/TVJ.201003.0045

摘要

豬瘟(classical swine fever; CSF)是台灣豬場重大的病毒性傳染病，具有高度傳染性和高致死率，對養豬業者威脅甚鉅。目前台灣在兔化豬瘟疫苗的使用下雖使豬瘟疫情趨緩式微，但仍不斷有零星疫情發生。因此，在田問使用疫苗後之抗體表現以及是否仍有野外毒之存在仍有待探討。本研究於台灣地區共20家豬場收集480隻豬隻樣本，每場採24頭，分別於肉豬第一劑豬瘟疫苗施打前及最後一劑施打後6週，逢機選取豬隻各12頭，採取血液及扁桃腺刮取物。所有血液樣本以商業化豬瘟病毒抗體檢測套組進行抗體檢測，而扁桃腺刮取物則進行豬瘟病毒RNA E2及NS5B基因之反轉錄聚合酶鏈鎖反應(RT-PCR)和基因定序。EUSA結果顯示，所有20家豬場免疫後良好率約70%，全部仔豬豬瘟疫苗免疫注射前後之平均blocking數值分別為62.82%和73.13%，而E2及NS5B基因之反轉錄聚合酶鏈鎖反應(RT-PCR)檢測結果顯示，有14.2%(34/240)和17.5%(42/240)豬隻於免疫前後分別檢出陽性樣本，另外進行E2及NS5B序列比對分析結果顯示，所檢測出的豬瘟病毒皆為疫苗毒，但豬場普遍皆有稍微過早施打第一劑豬瘟疫苗的問題值得注意。

關鍵字

豬瘟 ； E2 ； NS5B ； LPC豬瘟疫苗

並列摘要

Classical Swine Fever (CSF) is a highly contagious and fatal viral disease which is seriously threatening to Taiwan pig farms. After the usage of lapinized attenuated live vaccine, the outbreaks of CSF have significantly decreased. However, the concerns regarding antibody performance and existence of wild strain of CSFV in the pig farms remain. In this study, we collected 480 blood and tonsil scraping samples from 20 pig farms selected from mid- to southern Taiwan. There were 24 pigs randomly chosen from each farm with 12 each from pigs before first (BV) and 6 weeks after last vaccination (AV). All blood samples were examined for antibody detection using a commercial ELISA kit and tonsil scraping for CSFV E2 and NS5B RT-PCR and sequencing. Serological results showed that these 20 pig farms with excellent performance after last vaccination was 70%. The ELI- SA blocking values were 62.82% and 73.13% and RT-PCR results of E2 and NS5B genes were 14.2% (34/240) and 17.5% (42/240) BV and AV, respectively. The sequencing analysis of partial fragments of E2 and NS5B indicated that all viruses detected belong to the vaccine LPC strain. Taken together, many of pigs with high titers of antibodies BV indicated that generally the pig farms had the early vaccination problem.

並列關鍵字

Classical swine fever ； E2 ； NS5B ； LPC strain