探討E型肝炎病毒在豬隻、動物園野生動物及環境中野鼠的感染

Detection of Hepatitis E Virus (HEV) Infection in Pigs, Zoo Animals and Environmental Rodents in Taiwan

陳珮菁(Pei-Ching Chen) ； 龐飛(Victor Fei Pang) ； 蕭世烜(Shih-Hsuan Hsiao) ； 張聰洲(Tsung-Chou Chang) ； 張志成(Chih-Cheng Chang) ； 張志華(Chih-Hua Chang) ； 吳肇卿(Jaw-Ching Wu) ； 鄭謙仁(Chian-Ren Jeng)

《臺灣獸醫學雜誌》 36卷2期 (2010/06) Pp. 124-131

https://doi.org/10.7009/TVJ.201006.0124

摘要

E型肝炎病毒(Hepatitis E virus; HEV)是糞口途徑傳播，為許多發展中國家和工業化國家非A及非B型肝炎中的主要病因。因此HEV在台灣地區可能也是一個重要的人畜共通疾病。因此本研究針對豬隻、動物園動物及環境野鼠進行HEV檢測。本研究於2006年至2007年共收集台灣南部地區病死或病弱豬隻196例，以RT nested-PCR檢測，HEV陽性率為7.65%(15/196)。不同檢測樣本中，以糞便樣本檢出率較高，為9.72%(7/72)，肝臟樣本陽性率為5.22%(7/134)，膽汁樣本陽性率為2.13%(2/94)。以感染豬隻年齡進行分析，4至9週齡豬隻的陽性比例較高，為9.65%(11/114)，0至4週齡陽性比例為4.26%(2/47)，9至16週齡陽性比例為6.67%(2/30)，16週齡以上豬隻的陽性比例為0%(0/5)。將HEV PCR增幅產物定序，並與台灣發表的5株HEV基因序列比對，其相似性達80.8%-93.7%，與其他國家的HEV genotype 4相似性達84.0%-88.9%，與genotype 2及genotype 3的序列相似性分別為66.6%-68.6%及71.8%-76.3%。本研究之動物園野生動物及其環境野鼠肝臟樣本的PCR檢測結果均無陽性病例被檢出（0/144及0/14）。結果顯示HEV在台灣動物的感染仍以豬隻為主，其中又以4至9週齡豬隻的陽性比例較高，另外，核酸序列分析結果證實台灣HEV應屬於本土特異株。

關鍵字

E型肝炎病毒 ； 豬 ； 野生動物 ； RT nested-PCR ； 本土特異株

並列摘要

Hepatitis E virus (HEV) is the major cause of enterically transmitted non-A, non-B hepatitis in many developing countries and is also endemic in many industrialized countries. The recent discovery of HEV in domestic pigs and wild animals in United States and Japan, respectively, has suggested that HEV may be an important zoonotic issue in Taiwan. (Based on recent discovery of HEV in domestic pigs and wild animals in United States and Japan, respectively, HEV may be also an important zoonotic issue in Taiwan.) Thus, the aim of this study was to investigate HEV infection in pigs, zoo animals and environmental rodents in Taiwan. Between 2006 and 2007, 17 serum samples, 136 liver samples, 102 bile samples and 104 fecal samples were collected from pig(s) in the) farms (during 2006 to 2007). Samples collected from Taipei city zoo included 13 (primates) liver samples of primates, 52 mammals' liver samples, 45 reptiles' liver samples, 34 avian liver samples and 14 liver samples from environmental rodents. HEV RNA from homogenates of the samples was detected by reverse transcriptase nested polymerase chain reaction (RT nested-PCR). HEV positive signals were detected in 7 of 134 (5.22%) liver samples, 2 of 94 (2.13%) bile samples and 7 of 72 (9.72%) fecal samples from pig(s) farms. The porcine serum samples and all liver samples from zoo animals and environmental rodents were all (HEV) negative. The highest HEV positive rate (9.65%) was (detected) in pigs of 4 to 9 weeks age, and the HEV positive rate was 6.67% and 4.26% in pigs of 9 to 16 weeks and 0 to 4 weeks age, respectively. (In addition,) no positive samples present in pigs older than 16 weeks age. The identity (homology) of nucleotide sequences of PCR products was 80.8%-93.7% homology between swine and human HEV strains in Taiwan, 84.0%-88.9% homology between genotype 4 strains from different countries, and 66.6%-68.6% and 71.8%-76.3% homology between genotype 2 and genotype 3 strains, respectively. This study confirmed that the major animal of HEV infections (HEV reservoir; HEV-infected animal) in Taiwan is pigs, and the most susceptible age is from 4 to 9 weeks. Besides, the result of sequence analysis also supports(ed) that HEV of Taiwan isolates (HEV isolates in Taiwan; the isolated strain of HEV in Taiwan) belongs to an unique local or regional strain.

並列關鍵字

HEV ； Pigs ； wild animal ； RT nested-PCA ； local strain