劉 君,程訓(xùn)佳,潘孝彰
因生食或半生食含有感染期寄生蟲(chóng)的食物而感染的寄生蟲(chóng)病,稱(chēng)為食源性寄生蟲(chóng)病,如該寄生蟲(chóng)為吸蟲(chóng),則導(dǎo)致食源性吸蟲(chóng)病(food-borne trematodiasis,FBT)。FBT也是被忽視的熱帶?。╪eglected tropicaldiseases,NTDs)系列的一類(lèi)疾病[1-2]。與其他NTDs一樣,由于這類(lèi)疾病長(zhǎng)期主要在貧窮落后的部分區(qū)域流行,因而一直不被重視。但隨著全球經(jīng)濟(jì)的發(fā)展及交通的便捷,食物的生產(chǎn)、加工、運(yùn)輸與消耗呈現(xiàn)一體化,導(dǎo)致FBT患病人群數(shù)量增加的趨勢(shì)。目前全世界90%的水產(chǎn)品由亞洲提供,隨著淡水產(chǎn)品在全球范圍的消耗,與淡水魚(yú)蝦及淡水植物關(guān)系密切的FBT流行區(qū)域同步出現(xiàn)上升趨勢(shì)[3]。
常見(jiàn)的FBT的病原體包括:華支睪吸蟲(chóng)(肝吸蟲(chóng))、肝片形吸蟲(chóng)、巨片形吸蟲(chóng)、貓后睪吸蟲(chóng)、麝貓后睪吸蟲(chóng)、衛(wèi)氏并殖吸蟲(chóng)及布氏姜片吸蟲(chóng)。人患FBT是因食入含有囊蚴的食物或飲入被囊蚴污染的水而感染。不同種類(lèi)的吸蟲(chóng)在人體寄生的部位不同,其中華支睪吸蟲(chóng)、肝片形吸蟲(chóng)、巨片形吸蟲(chóng)、貓后睪吸蟲(chóng)及麝貓后睪吸蟲(chóng)寄生于肝臟,引起肝臟吸蟲(chóng)??;衛(wèi)氏并殖吸蟲(chóng)寄生于肺,引起肺吸蟲(chóng)病;布氏姜片吸蟲(chóng)寄生于腸道,引起腸吸蟲(chóng)病。不同種類(lèi)吸蟲(chóng)病的臨床表現(xiàn)和診斷方法不盡相同,本文主要介紹
肝臟吸蟲(chóng)、肺吸蟲(chóng)和腸吸蟲(chóng)3類(lèi)吸蟲(chóng)生活史不盡相同。當(dāng)成蟲(chóng)在人體內(nèi)發(fā)育成熟后在人體內(nèi)排出蟲(chóng)卵,蟲(chóng)卵隨糞便或痰液進(jìn)入外界淡水環(huán)境,在淡水螺體內(nèi)進(jìn)行無(wú)性增殖,經(jīng)胞蚴、雷蚴發(fā)育為尾蚴,從螺體內(nèi)逸出。不同蟲(chóng)種的尾蚴進(jìn)入淡水后發(fā)育過(guò)程有所不同,華支睪吸蟲(chóng)的尾蚴侵入淡水魚(yú)蝦的體內(nèi),在其肌肉內(nèi)發(fā)育為囊蚴,人或其他食肉動(dòng)物在食入生或半生的魚(yú)蝦后感染。肝片形吸蟲(chóng)、巨片形吸蟲(chóng)及布氏姜片吸蟲(chóng)的尾蚴進(jìn)入淡水后,在水生植物或其他物體甚至在水體中發(fā)育成囊蚴,當(dāng)人或其他動(dòng)物食入或飲入被囊蚴污染的植物或水而被感染。肺吸蟲(chóng)的尾蚴從螺體內(nèi)逸出后,鉆入淡水蟹及蝲蛄體內(nèi),在其肌肉內(nèi)發(fā)育為囊蚴,當(dāng)人或其他動(dòng)物食入生或半生的淡水蟹及蝲蛄?xí)r便被感染。
2.1.1 疾病概述 可寄生在人體肝臟的食源性吸蟲(chóng)主要有華支睪吸蟲(chóng)、肝片形吸蟲(chóng)、巨片形吸蟲(chóng)、麝貓后睪吸蟲(chóng)和貓后睪吸蟲(chóng)5種。它們寄生在人體肝臟的膽管和膽囊等部位,寄生后是否出現(xiàn)臨床癥狀取決于感染吸蟲(chóng)的種類(lèi)、數(shù)量、寄生部位及宿主的免疫反應(yīng)。多數(shù)患者輕度感染時(shí)臨床癥狀輕,不易被察覺(jué);中度感染時(shí)可出現(xiàn)發(fā)熱、疲倦、厭食及胃腸不適等癥狀;重度感染時(shí)可出現(xiàn)嚴(yán)重腹瀉,或腹瀉與便秘交替出現(xiàn)以及惡心、膽絞痛、消化不良、營(yíng)養(yǎng)不良及貧血等癥狀,還可導(dǎo)致膽石癥、膽汁淤積、膽管炎、膽囊炎、肝膿腫、肝硬化、胰腺炎和肝炎,更為嚴(yán)重的是,華支睪吸蟲(chóng)和麝貓后睪吸蟲(chóng)還可引起膽管癌[3-6]。
雖然目前關(guān)于膽管癌的發(fā)病機(jī)制還不確定,但寄生蟲(chóng)對(duì)膽管的刺激是重要因素[7-10]。國(guó)際癌癥研究署分別在1994年和2009年確定麝貓后睪吸蟲(chóng)和華支睪吸蟲(chóng)是兩種明確的致癌病原體[11-12]。膽管癌是食源性吸蟲(chóng)導(dǎo)致人體死亡常見(jiàn)的疾病,而且當(dāng)膽管癌與肝臟吸蟲(chóng)病并存時(shí),癥狀混雜不易辨別,給及時(shí)診斷帶來(lái)困難[13]。然而貓后睪吸蟲(chóng)和肝片形吸蟲(chóng)不具致癌性[11-12,14]。肝片形吸蟲(chóng)可在人體引起異位寄生,以皮膚、眼、腹部、心臟等部位常見(jiàn),在極少情況下還可導(dǎo)致宿主死亡[15]。
2.1.2 檢測(cè)方法 肝臟吸蟲(chóng)病最常用的診斷方法是糞檢法,雖然這種方法具有操作簡(jiǎn)單、取樣方便、無(wú)創(chuàng)傷的優(yōu)點(diǎn),但直接涂片法常因蟲(chóng)卵數(shù)量少、體積小而導(dǎo)致檢出率低。改良福爾馬林-醋酸乙酯濃集法、改良加藤涂片法和斯托爾稀釋蟲(chóng)卵計(jì)數(shù)法可提高檢出率[16-18]。但在蟲(chóng)體未發(fā)育成熟尚未排蟲(chóng)卵、感染強(qiáng)度不大或膽管堵塞后蟲(chóng)卵排不出來(lái)的情況下,糞檢法診斷的陽(yáng)性率會(huì)明顯降低。并且糞檢法對(duì)檢驗(yàn)人員要求較高,尤其是對(duì)于肝臟吸蟲(chóng)病患者中大多數(shù)的輕度感染者的診斷尤其重要。當(dāng)患者體內(nèi)寄生的蟲(chóng)荷低于20條或當(dāng)檢測(cè)的糞便中蟲(chóng)卵數(shù)低于1000個(gè)/g時(shí),檢出率將下降20%[19]。檢獲蟲(chóng)卵不僅可通過(guò)糞便,還可通過(guò)鼻膽管、經(jīng)皮肝穿刺膽道引流或經(jīng)十二指腸引流獲得。當(dāng)使用驅(qū)蟲(chóng)藥物時(shí)也可以檢獲成蟲(chóng)。
目前一些血清學(xué)方法也用于診斷肝臟吸蟲(chóng)病,如皮內(nèi)試驗(yàn)、免疫電泳、間接血凝試驗(yàn)、間接熒光抗體試驗(yàn)和間接酶聯(lián)免疫吸附試驗(yàn)等[20-22]。間接酶聯(lián)免疫吸附試驗(yàn)在血清學(xué)診斷中最為常用,但由于蟲(chóng)體抗原成分多,導(dǎo)致這種方法的靈敏度和特異度不穩(wěn)定,但檢測(cè)的靈敏度及特異度明顯高于糞檢法[20,23-24]。目前酶聯(lián)免疫吸附試驗(yàn)可用重組抗原檢測(cè)血清抗體[24-25]。組織蛋白酶L的前肽、谷胱甘肽-S-轉(zhuǎn)移酶、腺苷酸激酶3、磷酸甘油酸酯激酶、組織蛋白酶B/F、豆莢蛋白和咪基?;撬峒っ冈\斷肝臟吸蟲(chóng)病較糞檢法有更好的靈敏度和特異度[26-28]。目前,通過(guò)酶聯(lián)免疫吸附試驗(yàn)檢測(cè)尿液和唾液等非糞便中的抗原被認(rèn)為是一種潛在的血清學(xué)診斷后睪吸蟲(chóng)病方法[29]?;诳贵w檢測(cè)方法的一個(gè)缺點(diǎn)是不能區(qū)分患者在檢測(cè)時(shí)是否仍在感染??朔@一缺陷可通過(guò)使用抗原診斷確定人體內(nèi)是否有蟲(chóng)體[30]。單克隆抗體檢測(cè)及糞便抗原檢測(cè)可以檢測(cè)出宿主的感染狀況,即使宿主體內(nèi)蟲(chóng)荷很低,糞檢法結(jié)果為陰性。因此這兩種方法對(duì)輕度感染者進(jìn)行診斷及在治療后對(duì)治療效果進(jìn)行評(píng)估特別適合。
分子生物學(xué)方法也在不斷開(kāi)發(fā)用以診斷肝臟吸蟲(chóng)病。目前華支睪吸蟲(chóng)和貓后睪吸蟲(chóng)的部分基因可用于診斷,如衛(wèi)星DNA、內(nèi)轉(zhuǎn)錄區(qū)(internal transcribed spacer,ITS)1、ITS2和線(xiàn)粒體 DNA 等[31]。PCR及實(shí)時(shí)PCR(real-time PCR,RT-PCR)診斷肝臟吸蟲(chóng)病特異度高但靈敏度變化大,這與感染的強(qiáng)度有關(guān)。如貓后睪吸蟲(chóng)的蟲(chóng)卵達(dá)到1000個(gè)/g糞便時(shí),其靈敏度為100%,當(dāng)蟲(chóng)卵密度為200個(gè)/g糞便時(shí),靈敏度只有68%[32]。貓后睪吸蟲(chóng)的反轉(zhuǎn)錄轉(zhuǎn)座子作為一種新的PCR診斷肝片形吸蟲(chóng)病的標(biāo)記物具有很高的靈敏度和特異度[33]。特異性引物PCR可區(qū)分貓后睪吸蟲(chóng)、麝貓后睪吸蟲(chóng)及華支睪吸蟲(chóng)[34-35]。另一些方法或基因標(biāo)記物如PCR、限制性片段長(zhǎng)度多態(tài)性PCR、多重PCR、RT-PCR及多重連接依賴(lài)性探針擴(kuò)增焦磷酸測(cè)序等可用以區(qū)別不同種類(lèi)的肝臟吸蟲(chóng)[36-37]。各種分子生物學(xué)的診斷方法正在不斷研究,用于在流行區(qū)進(jìn)行肝臟吸蟲(chóng)病的診斷及治療后的療效評(píng)估[38]。
2.1.3 治療 對(duì)于肝臟吸蟲(chóng)病的治療,因蟲(chóng)種不同而異,針對(duì)華支睪吸蟲(chóng)可使用的藥物較多,常用的包括氯喹、六氯對(duì)二甲苯、吡喹酮和阿苯達(dá)唑等;而針對(duì)貓后睪吸蟲(chóng)和麝貓后睪吸蟲(chóng),常用吡喹酮;針對(duì)肝片形吸蟲(chóng)和巨片形吸蟲(chóng)可使用三氯苯達(dá)唑和碘醚柳胺等。
2.2.1 疾病概述 肺吸蟲(chóng)病是由衛(wèi)氏并殖吸蟲(chóng)寄生在肺部引起的疾病。該吸蟲(chóng)是最常見(jiàn)的可引起異位寄生的食源性吸蟲(chóng)。異位寄生的部位或器官包括腦、皮膚、眼、腹部器官、生殖器或中樞神經(jīng)系統(tǒng)等[39]。肺吸蟲(chóng)病可導(dǎo)致患者出現(xiàn)出血性肺炎、氣胸、胸膜肺囊腫、肺膿腫等。嚴(yán)重的胸膜肺吸蟲(chóng)病癥狀與結(jié)核性肺炎、支氣管肺炎及哮喘性肺炎相似,如慢性咯血、胸痛、呼吸困難等。衛(wèi)氏并殖吸蟲(chóng)寄生在肺部后可長(zhǎng)期無(wú)癥狀,多數(shù)患者在感染約半年時(shí)緩慢發(fā)病,病程較長(zhǎng),常見(jiàn)臨床癥狀包括咳嗽、發(fā)熱、血痰、食欲不振、胸痛、頭痛及盜汗等,慢性感染時(shí)癥狀與肺結(jié)核病相似。肺吸蟲(chóng)病導(dǎo)致患者死亡的最常見(jiàn)的原因是由于寄生在腦部引起的病變,可表現(xiàn)為頭痛、精神錯(cuò)亂、行為失常、腦膜刺激征、抽搐、偏癱、視力障礙及腦出血。
2.2.2 檢測(cè)及治療 對(duì)于肺吸蟲(chóng)病的診斷可通過(guò)蟲(chóng)卵進(jìn)行鑒定。但在患者痰液中檢測(cè)蟲(chóng)卵靈敏度低,并且蟲(chóng)卵在患者感染2~3個(gè)月蟲(chóng)體成熟后才產(chǎn)出,因此在感染早期時(shí)診斷使用該法不可靠,而通過(guò)糞檢法檢獲蟲(chóng)卵其靈敏度更低[40]。與肝臟吸蟲(chóng)病的診斷相似,目前血清學(xué)及分子生物學(xué)多種診斷方法用于診斷肺吸蟲(chóng)病,但同樣存在抗原成分多、特異性引物少的問(wèn)題,導(dǎo)致不同檢測(cè)方法的靈敏度和特異度有所不同[40-41]。目前影像學(xué)診斷也逐漸在臨床上用以診斷肺吸蟲(chóng)病,如計(jì)算機(jī)斷層掃描和核磁共振成像等[42]。關(guān)于肺吸蟲(chóng)病的治療,主要是在排除腫瘤等需鑒別診斷的疾病后,給予抗病原體治療,可使用的藥物包括吡喹酮和三氯苯達(dá)唑[43]。
2.3.1 疾病概述 能引起腸吸蟲(chóng)病的食源性吸蟲(chóng)主要是布氏姜片吸蟲(chóng)。布氏姜片吸蟲(chóng)在人體主要寄生在腸道,偶爾會(huì)引起異位寄生,極少數(shù)情況下可導(dǎo)致宿主死亡[15]。布氏姜片吸蟲(chóng)由于吸盤(pán)發(fā)達(dá),吸附能力強(qiáng),可導(dǎo)致被吸附部位的腸黏膜壞死脫落,發(fā)生炎癥、出血及水腫而形成潰瘍或膿腫,導(dǎo)致腸道梗阻及潰瘍[6]。輕度感染者可無(wú)明顯癥狀,寄生蟲(chóng)數(shù)量較多時(shí)常出現(xiàn)腹痛、腹瀉及消化不良,患者排便量多,便稀薄而臭,或腹瀉與便秘交替出現(xiàn),甚至出現(xiàn)腸梗阻。在營(yíng)養(yǎng)不良的患者中曾出現(xiàn)反復(fù)中毒感染的病例,尤其是兒童,可出現(xiàn)低熱、消瘦、貧血、水腫、腹水以及智力減退和發(fā)育障礙,少數(shù)患者可因多器官衰竭而死亡。
2.3.2 檢測(cè)及治療 腸吸蟲(chóng)病的診斷目前仍以糞檢法查獲蟲(chóng)卵為“金標(biāo)準(zhǔn)”,但是寄生在人體腸道的寄生蟲(chóng)種類(lèi)多,有些種類(lèi)的蟲(chóng)卵形態(tài)相似,僅通過(guò)蟲(chóng)卵進(jìn)行蟲(chóng)種的鑒定易造成誤診。并且糞檢蟲(chóng)卵時(shí)易受到蟲(chóng)體發(fā)育成熟與否、糞便中蟲(chóng)卵的分布與數(shù)量及檢測(cè)人員檢測(cè)水平等因素的影響。由于布氏姜片吸蟲(chóng)寄生在腸道,對(duì)人體血清的影響不如肝臟吸蟲(chóng)和肺吸蟲(chóng)大,因此目前通過(guò)血清學(xué)方法和分子生物學(xué)方法診斷的報(bào)道還不多[44]。對(duì)于腸吸蟲(chóng)病的病原治療,目前使用的藥物有吡喹酮、硫雙二氯酚、強(qiáng)氯扎胺和左旋咪唑等,一些植物提取物也被開(kāi)發(fā)用于治療[45]。
隨著對(duì)FBT的研究,人們逐漸認(rèn)識(shí)到這類(lèi)疾病不僅具有危害大、流行廣及診斷難的特點(diǎn),并且有些種類(lèi)寄生蟲(chóng)還可作為致癌因素對(duì)健康構(gòu)成較大的危害。在對(duì)這些寄生蟲(chóng)病診斷研究過(guò)程中,結(jié)合其他學(xué)科不斷開(kāi)發(fā)出了靈敏度和特異度更高的診斷方法,雖然目前有些技術(shù)手段還不成熟,但可為將來(lái)的進(jìn)一步研究發(fā)展奠定較好的基礎(chǔ)。目前雖然已有一些藥物可用于治療FBT,但這些藥物的不良反應(yīng)及蟲(chóng)株對(duì)藥物逐漸產(chǎn)生的耐藥性影響其療效,因此迫切須要尋求開(kāi)發(fā)更高效低毒的藥物。
[1]Utzinger J,de Savigny D.Control of neglected tropical diseases:integrated chemotherapy and beyond[J].PLoSMed,2006,3(5):e112.
[2]Torgerson PR,de Silva NR,Fèvre EM,etal.The global burden of foodborne parasitic disease:an update[J].Trends Parasitol,2014,30(1):20-26.
[3]Keiser J,Utzinger J.Food-borne trematodiases[J].Clin Microbiol Rev,2009,22:466-483.
[4] 王姝雅.華支睪吸蟲(chóng)病的感染及流行病學(xué)分析[J].中國(guó)衛(wèi)生標(biāo)準(zhǔn)管理,2014,22:92-93.
[5] 劉國(guó)興,吳秀萍,王子見(jiàn),等.三種吸蟲(chóng)感染與膽管癌發(fā)病關(guān)系的研究進(jìn)展[J].中國(guó)寄生蟲(chóng)學(xué)與寄生蟲(chóng)病雜志,2010,28(4):301-305.
[6]Keiser J,Utzinger J.Emerging foodborne trematodiasis[J].Emerg Infect Dis,2005,11(10):1507-1514.
[7]Lim JH.Liver flukes:the malady neglected[J].Korean JRadiol,2011,12(3):269-279.
[8]Choi BI,Han JK,Hong ST,etal.Clonorchiasis and cholangiocarcinoma:etiologic relationship and imaging diagnosis[J].Clin Microbiol Rev,2004,17(3):540-552.
[9]Sripa B,Kaewkes S,Sithithaworn P,et al.Liver fluke induces cholangiocarcinoma[J].PLoSMed,2007,4(7):e201.
[10]Shimonishi T,Sasaki M,Nakanuma Y.Precancerous lesions of intrahepatic cholangiocarcinoma[J].JHepatobiliary Pancreat Surg,2000,7(6):542-550.
[11][No authors listed].Infection with liver flukes(Opisthorchis viverrini,Opisthorchis felineus and Clonorchis sinensis)[J].IARCMonogr Eval Carcinog Risks Hum,1994,61:121-75.
[12]Bouvard V,Baan R,Straif K,et al.A review of human carcinogens-Part B:biological agents[J].Lancet Oncol,2009,10(4):321-322.
[13]Blechacz BRA,Gores GJ.Cholangiocarcinoma[J].Clin Liver Dis,2008,12:131-150.
[14]劉倩,程娜,周巖,等.片形吸蟲(chóng)病研究進(jìn)展[J].中國(guó)寄生蟲(chóng)學(xué)與寄生蟲(chóng)病雜志,2013,31(3):229-234.
[15]Fried B,Graczyk TK,Tamang L.Food-borne intestinal trematodiases in humans[J].Parasitol Res,2004,93(2):159-170.
[16]Elkins DB,Haswell-Elkins MR,Mairiang E,etal.A high frequency of hepatobiliary disease and suspected cholangiocarcinoma associated with heavy Opisthorchis viverrini infection in a small community in north-east Thailand[J].Trans R Soc Trop Med Hyg,1990,84(5):715-719.
[17]Hong ST,ChoiMH,Kim CH,etal.The Kato-Katzmethod is reliable for diagnosis of Clonorchis sinensis infection[J].Diagn Microbiol Infect Dis,2003,47(1):345-347.
[18]Viyanant V,Brockelman WY,Lee P,et al.A comparison of a modified quick-Kato technique and the Stoll dilution method for field examination for Opisthorchis viverrini eggs[J].JHelminthol,1983,57(3):191-195.
[19]Sithithaworn P,Tesana S,Pipitgool V,etal.Relationship between faecal egg count and worm burden of Opisthorchis viverrini in human autopsy cases[J].Parasitology,1991,102(Pt2):277-281.
[20]Hong ST,Fang Y.Clonorchis sinensis and clonorchiasis,an update[J].Parasitol Int,2012,61(1):17-24.
[21]Kim TY,Lee YS,Yun JH,etal.A case of probablemixed-infec-tion with Clonorchis sinensis and Fasciola sp.:CT and parasitological findings[J].Korean JParasitol,2010,48(2):157-160.
[22]Wongratanacheewin S,Sermswan RW,Sirisinha S.Immunology and molecular biology of Opisthorchis viverrini infection[J].Acta Trop,2003,88(3):195-207.
[23]Poopyruchpong N,Viyanant V,Upatham ES,et al.Diagnosis of opisthorchiasis by enzyme-linked immunosorbent assay using partially purified antigens[J].Asian Pac JAllergy Immunol,1990,8(1):27-31.
[24]Wongsaroj T,Sakolvaree Y,ChaicumpaW,etal.Affinity purified oval antigen for diagnosis of Opisthorchiasis viverrini[J].Asian Pac JAllergy Immunol,2001,19(4):245-258.
[25]Ruangsittichai J,Viyanant V,Vichasri-Grams S,et al.Opisthorchis viverrini:identification of a glycine-tyrosine rich eggshell protein and its potential as a diagnostic tool for human opisthorchiasis[J].Int JParasitol,2006,36(13):1329-1339.
[26]Chen J,Xu H,Zhang Z,etal.Cloning and expression of 21.1-kDa tegumental protein of Clonorchis sinensis and human antibody response to it as a trematode-nematode pan-specific serodiagnosis antigen[J].Parasitol Res,2011,108(1):161-168.
[27]Li S,Shin JG,Cho PY,et al.Multiple recombinant antigens of Clonorchis sinensis for serodiagnosis of human clonorchiasis[J].Parasitol Res,2011,108(5):1295-1302.
[28]Li Y,Hu X,Liu X,etal.Serological diagnosis of clonorchiasis:us ing a recombinant propeptide of cathepsin L proteinase from Clonorchis sinensis as a candidate antigen[J].Parasitol Res,2012,110(6):2197-2203.
[29]Sawangsoda P,Sithithaworn J,Tesana S,etal.Diagnostic values of parasite-specific antibody detections in saliva and urine in comparison with serum in opisthorchiasis[J].Parasitol Int,2012,61(1):196-202.
[30]Sirisinha S,Chawengkirttikul R,Haswell-Elkins MR,etal.Evaluation of a monoclonal antibody-based enzyme linked immunosorbent assay for the diagnosis of Opisthorchis viverrini infection in an endemic area[J].Am JTrop Med Hyg,1995,52(6):521-524.
[31]Qiao T,Zheng PM,Ma RH,et al.Development of a real-time PCR assay for the detection of Clonorchis sinensis DNA in gallbladder bile and stone samples from patients with cholecystolithiasis[J].Parasitol Res,2012,111(4):1497-1503.
[32]Wongratanacheewin S,Pumidonming W,Sermswan RW,etal.Detection of Opisthorchis viverrini in human stool specimens by PCR[J].JClin Microbiol,2002,40(10):3879-3880.
[33]Phung LT,Loukas A,Brindley PJ,et al.Retrotransposon OVRTE-1 from the carcinogenic liver flukes Opisthorchis viverrini:potential target for DNA-based diagnosis[J].Infect Genet Evol,2014,21:443-451.
[34]Pauly A,Schuster R,Steuber S.Molecular characterization and differentiation of opisthorchiid trematodes of the species Opisthorchis felineus(Rivolta,1884)and Metorchis bilis(Braun,1790)using polymerase chain reaction[J].Parasitol Res,2003,90(5):409-414.
[35]Le TH,Van De N,Blair D,et al.Clonorchis sinensis and Opisthorchis viverrini:development of a mitochondrial-based multiplex PCR for their identification and discrimination[J].Exp Parasitol,2006,112(2):109-114.
[36]Sanpool O,Intapan PM,Thanchomnang T,et al.Rapid detection and differentiation of Clonorchis sinensis and Opisthorchis viverrini eggs in human fecal samples using a duplex real-time fluorescence resonance energy transfer PCR and melting curve analysis[J].Parasitol Res,2012,111(1):89-96.
[37]Sun J,Xu J,Liang P,etal.Molecular identification of Clonorchis sinensis and discrimination with other opisthorchid liver fluke species using multiple Ligation-depended Probe Amplification(MLPA)[J].Parasit Vectors,2011,4:98.
[38]Duenngai K,Boonmars T,Sithithaworn J,etal.Diagnosis of early infection and post chemotherapeutic treatment by copro-DNA detection in experimental opisthorchiasis[J].Parasitol Res,2013,112(1):271-278.
[39]Gadkowski LB,Jason ES.Cavitary pulmonary disease[J].Clin Microbiol Rev,2008,21(2):305-333.
[40]Procop GW.North American paragonimiasis(caused by Paragonimus kellicotti)in the context of global paragonimiasis[J].Clin Microbiol Rev,2009,22(3):415-446.
[41]López-Caballero J,Oceguera-Figueroa A,León-Règagnon V.Detection of multiple species of human Paragonimus from Mexico usingmorphological data andmolecular barcodes[J].Mol Ecol Resour,2013,13(6):1125-1136.
[42]Henry TS,Lane MA,Weil GJ,et al.Chest CT features of North American paragonimiasis[J].AJR Am JRoentgenol,2012,198(5):1076-1083.
[43]Liu Q,Wei F,Liu W,et al.Paragonimiasis:an important foodborne zoonosis in China[J].Trends parasitol,2008,24(7):318-323.
[44]Johansen MV,Sithithaworn P,Bergquist R,et al.Towards improved diagnosis of zoonotictrematode infections in Southeast Asia[J].Adv Parasitol,2010,73:171-195.
[45]Abdel-Ghaffar F,Semmler M,Al-Rasheid KA,et al.The effects of different plant extracts on intestinal cestodes and on trematodes[J].Parasitol Res,2011,108(4):979-984.