Ponterio Eleonora, Di Bartolo Ilaria, Orrù Ginevra, Liciardi Manuel, Ostanello Fabio, Ruggeri Franco Maria
Department of Veterinary Public Health and Food Safety, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy.
BMC Vet Res. 2014 Jun 16;10:133. doi: 10.1186/1746-6148-10-133.
The hepatitis E virus (HEV) has been detected in both humans and animals, particularly pigs, worldwide. Several evidences, including human infection following consumption of raw contaminated meat, suggest a zoonotic transmission of HEV. In Italy, large circulation of genotype 3 HEV has been reported in swine, and recent studies have confirmed the involvement of this genotype in autochthonous human cases.
In this study 111 sera collected from healthy pigs in two Italian regions were tested for anti-HEV IgG antibodies. For specific HEV antibody detection in swine, we developed ELISA and Western blotting methods, using a truncated capsid (ORF2) protein lacking the first 111 amino acids of a swine HEV genotype 3 strain. The ORF2-based ELISA revealed anti-HEV antibodies in 104 out of 111 pigs compared with 102 detected with a commercial ELISA kit. A lower number of sera reacted with the recombinant ORF2 protein in a Western blotting format (81/111). Using a Latent class analysis (LCA), the estimated sensitivities for ELISA-ORF2 and ELISA-kit tests were 0.961 and 0.936, respectively, whereas specificities were 0.599 and 0.475. The estimated sensitivity of Western blotting was 0.775, and the specificity was 0.944.
The overall results confirm the high prevalence of HEV seropositive healthy pigs in Italy. Through comparisons with a commercial ELISA test, the swine genotype 3 HEV antigen produced in this study was proven suitable to detect anti-HEV antibodies in pig sera by both ELISA and Western Blotting.
戊型肝炎病毒（HEV）在全球范围内的人类和动物中均有发现，尤其是猪。包括食用受污染生肉后发生人类感染在内的多项证据表明，HEV存在人畜共患传播。在意大利，已报道猪群中3型HEV广泛传播，近期研究证实该基因型与本土人类病例有关。
本研究检测了意大利两个地区111头健康猪的血清中的抗HEV IgG抗体。为在猪中特异性检测HEV抗体，我们开发了ELISA和蛋白质印迹法，使用的是一种截短的衣壳（ORF2）蛋白，该蛋白缺少猪3型HEV毒株的前111个氨基酸。基于ORF2的ELISA显示，111头猪中有104头存在抗HEV抗体，而使用商用ELISA试剂盒检测到102头。采用蛋白质印迹法时，与重组ORF2蛋白发生反应的血清数量较少（81/111）。使用潜在类别分析（LCA），ELISA-ORF2和ELISA试剂盒检测的估计灵敏度分别为0.961和0.936，而特异性分别为0.599和0.475。蛋白质印迹法的估计灵敏度为0.775，特异性为0.944。
总体结果证实了意大利HEV血清学阳性健康猪的高流行率。通过与商用ELISA检测进行比较，本研究中产生的猪3型HEV抗原经证实适用于通过ELISA和蛋白质印迹法检测猪血清中的抗HEV抗体。
