結(jie)(jie)膜(mo)(mo)吸(xi)吮線(xian)蟲(chong)(Thelazia callipaeda(Railliet&Henry,1910)是指吸(xi)吮科吸(xi)吮線(xian)蟲(chong)屬的一(yi)種線(xian)蟲(chong)。主要(yao)寄生于(yu)犬、貓等動(dong)物眼(yan)(yan)結(jie)(jie)膜(mo)(mo)囊內,也可寄生于(yu)人眼(yan)(yan),引起結(jie)(jie)膜(mo)(mo)吸(xi)吮線(xian)蟲(chong)病(thelaziasis)。因本病多流行于(yu)亞洲地(di)區,故又稱東方(fang)眼(yan)(yan)蟲(chong)病。成蟲(chong)蟲(chong)體(ti)細(xi)長呈(cheng)線(xian)狀(zhuang),圓柱形(xing)(xing),在人眼(yan)(yan)結(jie)(jie)膜(mo)(mo)囊寄居時呈(cheng)淡紅(hong)色(se),離開人體(ti)為乳(ru)白色(se)。蟲(chong)體(ti)表面(mian)具有邊緣銳利的環形(xing)(xing)皺褶,側面(mian)觀(guan)其(qi)上下排列呈(cheng)鋸(ju)齒(chi)狀(zhuang)。
成蟲(chong)(chong)(chong)蟲(chong)(chong)(chong)體(ti)(ti)細長呈(cheng)(cheng)線(xian)狀(zhuang),圓柱(zhu)形(xing),在人眼結膜囊(nang)寄居時呈(cheng)(cheng)淡紅色,離開人體(ti)(ti)為(wei)(wei)(wei)乳白色。蟲(chong)(chong)(chong)體(ti)(ti)表面(mian)(mian)具有邊緣(yuan)銳利的(de)環形(xing)皺褶,側面(mian)(mian)觀其上下(xia)排列呈(cheng)(cheng)鋸齒狀(zhuang)。雄(xiong)蟲(chong)(chong)(chong)大小一般(ban)為(wei)(wei)(wei)(4.5~15.0)mm×(0.25~0.75)mm,尾端向腹面(mian)(mian)彎曲,由泄殖(zhi)腔伸出(chu)2根交(jiao)合(he)刺,長短及(ji)形(xing)狀(zhuang)各異。雌(ci)蟲(chong)(chong)(chong)大小為(wei)(wei)(wei)(6.2~20.0)mm×(0.30~0.85)mm,蟲(chong)(chong)(chong)體(ti)(ti)腹面(mian)(mian)尾端有肛門(men),食管(guan)與腸結合(he)處(chu)的(de)腹面(mian)(mian)有陰門(men),雌(ci)蟲(chong)(chong)(chong)生殖(zhi)系統發(fa)達,為(wei)(wei)(wei)雙(shuang)管(guan)型,近(jin)陰門(men)端子宮內的(de)蟲(chong)(chong)(chong)卵(luan)(luan)逐漸發(fa)育為(wei)(wei)(wei)盤曲的(de)幼(you)(you)蟲(chong)(chong)(chong),雌(ci)蟲(chong)(chong)(chong)直接產出(chu)幼(you)(you)蟲(chong)(chong)(chong),為(wei)(wei)(wei)卵(luan)(luan)胎生。雌(ci)、雄(xiong)蟲(chong)(chong)(chong)尾端肛門(men)周圍(wei)均(jun)有數對乳突。食管(guan)陰門(men)幼(you)(you)蟲(chong)(chong)(chong)子宮腸雌(ci)蟲(chong)(chong)(chong)頭部(bu),雄(xiong)蟲(chong)(chong)(chong)尾部(bu)乳突交(jiao)合(he)刺。
初(chu)產幼(you)蟲大(da)小為(wei)(350~414)μm×(13~19)μm,外被鞘膜,呈盤(pan)曲(qu)狀(zhuang),尾部連接一(yi)膨大(da)氣球狀(zhuang)的鞘膜囊。
成(cheng)蟲(chong)(chong)主(zhu)(zhu)要寄(ji)生于犬、貓(mao)(mao)等動(dong)物(wu)的眼(yan)(yan)結膜囊及淚(lei)管內,偶爾寄(ji)生于人(ren)、兔(tu)等動(dong)物(wu)的眼(yan)(yan)部(bu)(bu)。本蟲(chong)(chong)屬(shu)卵(luan)胎生。雌成(cheng)蟲(chong)(chong)直(zhi)接產幼(you)蟲(chong)(chong)于結膜囊內,當中間宿(su)主(zhu)(zhu)果蠅(ying)(ying)舐(shi)吸終宿(su)主(zhu)(zhu)眼(yan)(yan)部(bu)(bu)分泌物(wu)時(shi)而被吸入蠅(ying)(ying)體內,經(jing)2次(ci)蛻皮發(fa)育(yu)為感染(ran)期幼(you)蟲(chong)(chong)后進人(ren)蠅(ying)(ying)的頭部(bu)(bu)口器(qi)。當蠅(ying)(ying)再舐(shi)吸入或(huo)其他動(dong)物(wu)眼(yan)(yan)部(bu)(bu)時(shi),感染(ran)期幼(you)蟲(chong)(chong)自(zi)蠅(ying)(ying)口器(qi)逸出并侵入宿(su)主(zhu)(zhu)眼(yan)(yan)部(bu)(bu),經(jing)15~20天發(fa)育(yu)為成(cheng)蟲(chong)(chong)。成(cheng)蟲(chong)(chong)壽命可達2年以上。終宿(su)主(zhu)(zhu):犬、貓(mao)(mao)(人(ren));中間宿(su)主(zhu)(zhu):蠅(ying)(ying);感染(ran)階段:絲(si)狀(zhuang)蚴;感染(ran)方式:媒介昆蟲(chong)(chong)舔舐(shi)眼(yan)(yan)部(bu)(bu)。
成蟲寄(ji)生(sheng)于人眼(yan)(yan)(yan)結(jie)膜囊(nang)內,以(yi)上(shang)結(jie)膜囊(nang)外眥(zi)側(ce)(ce)為多(duo)見,也可(ke)見于眼(yan)(yan)(yan)前房(fang)(fang)、淚(lei)(lei)小管、淚(lei)(lei)腺及眼(yan)(yan)(yan)瞼、結(jie)膜下等處。多(duo)侵犯一側(ce)(ce)眼(yan)(yan)(yan),少數病例可(ke)雙眼(yan)(yan)(yan)感染。寄(ji)居蟲數1條至數條,最多(duo)可(ke)達20余條。由于蟲體表(biao)面銳(rui)利環形(xing)(xing)(xing)皺折(zhe)的(de)摩擦、頭端口囊(nang)吸附作用等的(de)機械性損傷,加(jia)上(shang)蟲體分(fen)泌物(wu)、排泄物(wu)的(de)刺激及繼(ji)發(fa)(fa)細菌感染等,可(ke)引起眼(yan)(yan)(yan)結(jie)膜炎(yan)癥(zheng)反應及肉芽腫(zhong)形(xing)(xing)(xing)成。輕者無明顯癥(zheng)狀(zhuang),或有眼(yan)(yan)(yan)部異物(wu)感、癢感、刺痛、流(liu)淚(lei)(lei)、畏(wei)光(guang)、分(fen)泌物(wu)增多(duo)、疼(teng)痛等,一般無視力障礙(ai)。嬰幼兒不敢睜眼(yan)(yan)(yan),有手抓眼(yan)(yan)(yan)的(de)動作。家長可(ke)發(fa)(fa)現患兒眼(yan)(yan)(yan)球有白色細小的(de)蟲體爬行(xing)。重感染者可(ke)發(fa)(fa)生(sheng)結(jie)膜充血(xue),形(xing)(xing)(xing)成小潰瘍面,角(jiao)膜混濁、眼(yan)(yan)(yan)瞼外翻等。如(ru)寄(ji)生(sheng)在眼(yan)(yan)(yan)前房(fang)(fang),可(ke)有絲狀(zhuang)陰(yin)影移動感、睫狀(zhuang)體充血(xue)、房(fang)(fang)水混濁、眼(yan)(yan)(yan)壓升高、瞳孔(kong)擴大、視力下降(jiang)等。如(ru)淚(lei)(lei)小管受(shou)損,可(ke)出現淚(lei)(lei)點外翻。
診斷主要用鑷(nie)子或棉(mian)簽自眼部取出(chu)蟲體(ti),置(zhi)盛有生理鹽水的平皿中(zhong),可見蟲體(ti)蠕動,用顯微(wei)鏡檢(jian)查蟲體(ti)特征即(ji)可明確診斷。
本蟲(chong)(chong)(chong)(chong)主要(yao)分(fen)布(bu)在亞洲。印度、緬甸(dian)、菲律賓、泰國(guo)(guo)、日(ri)本、朝(chao)鮮及俄羅(luo)斯(si)的(de)(de)(de)遠東地區均有(you)病(bing)(bing)例報(bao)告。我國(guo)(guo)的(de)(de)(de)病(bing)(bing)例報(bao)告始于(yu)1917年,為世界最(zui)早發(fa)現。現已知(zhi)我國(guo)(guo)有(you)25個省、市、自治區有(you)人體感染(ran)的(de)(de)(de)病(bing)(bing)例報(bao)道,其中(zhong)以江(jiang)蘇、湖北、安徽、河南、山東等地的(de)(de)(de)病(bing)(bing)例較多。近年已證實岡(gang)田繞(rao)眼果蠅(Amiota okadai)是我國(guo)(guo)結膜吸吮(shun)線蟲(chong)(chong)(chong)(chong)的(de)(de)(de)中(zhong)間宿主,是本病(bing)(bing)的(de)(de)(de)傳播媒(mei)介。感染(ran)季(ji)(ji)節(jie)以夏秋(qiu)季(ji)(ji)為主,與蠅類(lei)的(de)(de)(de)季(ji)(ji)節(jie)消長相(xiang)吻合。感染(ran)者(zhe)最(zui)小(xiao)3個月(yue),最(zui)大者(zhe)88歲,但以嬰幼(you)兒為主。本病(bing)(bing)在農村多于(yu)城市。傳染(ran)源(yuan)主要(yao)為家(jia)犬,其次是貓、兔(tu)等動物。根(gen)據1982~1991年的(de)(de)(de)調查,安徽淮北重流(liu)行(xing)地區的(de)(de)(de)某些村鎮家(jia)犬的(de)(de)(de)感染(ran)率高達76.7%,每犬的(de)(de)(de)感染(ran)蟲(chong)(chong)(chong)(chong)數可(ke)在30~60條。保蟲(chong)(chong)(chong)(chong)宿主家(jia)犬的(de)(de)(de)普遍存在,媒(mei)介中(zhong)間宿主果蠅的(de)(de)(de)廣(guang)泛(fan)分(fen)布(bu),再加上幼(you)童不潔的(de)(de)(de)眼部(bu)衛生(sheng),是結膜吸吮(shun)線蟲(chong)(chong)(chong)(chong)病(bing)(bing)流(liu)行(xing)的(de)(de)(de)主要(yao)因(yin)素。
防蠅、滅蠅,搞好環境衛生,加強(qiang)犬(quan)、貓等(deng)動物管理,注(zhu)意個人衛生,特(te)別注(zhu)意眼部清(qing)潔是預防感染的(de)主要措施。治療可(ke)用(yong)1%~2%可(ke)卡因(yin)或地卡因(yin)溶液滴眼,蟲體受刺激(ji)從眼角爬出,或用(yong)鑷子(zi)取出。
病原體最初(chu)是從(cong)印(yin)(yin)度旁遮(zhe)普的(de)犬眼中發現(xian)的(de),以后在(zai)美國(guo)、緬甸、菲(fei)律賓、朝鮮、印(yin)(yin)度、日本、泰國(guo)、蘇聯、遠東地(di)區等地(di)陸續(xu)有犬體寄生的(de)報道。我國(guo)犬、貓的(de)感染甚為普遍而嚴重。
人(ren)體病例首(shou)先于1917年發(fa)現在(zai)我國。迄今報道(dao)已有百例以(yi)上(shang),分(fen)布于河北、福建、北京、江(jiang)蘇、四川、貴(gui)州、河南(nan)、安徽、湖南(nan)、湖北、東(dong)(dong)北、山(shan)東(dong)(dong)、天津、上(shang)海、云南(nan)、廣西等(deng)省市、自(zi)治區。其中以(yi)湖北、山(shan)東(dong)(dong)、江(jiang)蘇部分(fen)地區為(wei)最多(duo)。人(ren)體感染者年齡、性(xing)別(bie)無(wu)特殊性(xing),最小4個月,最高76歲。
成(cheng)蟲寄(ji)生(sheng)在結膜(mo)囊(nang)中,以口囊(nang)吸附在眼(yan)(yan)(yan)結膜(mo)上,并(bing)能自(zi)由移動,體表的皺(zhou)褶對(dui)患(huan)者(zhe)眼(yan)(yan)(yan)部造成(cheng)機(ji)械(xie)性(xing)損(sun)傷(shang),加(jia)之(zhi)蟲體分泌(mi)物(wu)(wu)和排(pai)泄物(wu)(wu)的化學(xue)性(xing)刺(ci)激,導致炎癥(zheng)(zheng)反(fan)應或肉芽腫(zhong)形成(cheng)。輕者(zhe)可(ke)(ke)無癥(zheng)(zheng)狀,也(ye)可(ke)(ke)有眼(yan)(yan)(yan)部異物(wu)(wu)感(gan)或癢(yang)感(gan)、流淚、畏光、眼(yan)(yan)(yan)部分泌(mi)物(wu)(wu)增(zeng)多(duo)、結膜(mo)充血或水腫(zhong),甚至眼(yan)(yan)(yan)痛(tong),但視(shi)力一(yi)般不受影響。取出蟲體后癥(zheng)(zheng)狀便可(ke)(ke)消失。如寄(ji)生(sheng)于眼(yan)(yan)(yan)前房,可(ke)(ke)見(jian)(jian)絲狀物(wu)(wu)浮(fu)動,房水混濁,眼(yan)(yan)(yan)壓增(zeng)高,并(bing)可(ke)(ke)形成(cheng)小潰瘍,重者(zhe)形成(cheng)疤痕,造成(cheng)角膜(mo)混濁等損(sun)害,也(ye)可(ke)(ke)引起繼發性(xing)青光眼(yan)(yan)(yan)、眼(yan)(yan)(yan)瞼(jian)外翻等并(bing)發癥(zheng)(zheng)。以單側眼(yan)(yan)(yan)部感(gan)染多(duo)見(jian)(jian),雙眼(yan)(yan)(yan)感(gan)染者(zhe)少見(jian)(jian)。成(cheng)蟲寄(ji)生(sheng)的數目(mu)常為1~10條,最多(duo)的一(yi)例多(duo)達(da)21條。
可無明(ming)顯(xian)自覺癥狀(zhuang)。成蟲(chong)(chong)(chong)在眼結膜囊自由行動,此蟲(chong)(chong)(chong)體的分泌物、排泄物可引(yin)(yin)起局(ju)部(bu)刺激癥狀(zhuang),眼部(bu)有(you)異物感、癢感、畏光(guang)、流淚、分泌物增多。如寄生在前房可見絲(si)狀(zhuang)物飄動,眼瞼水腫(zhong),結膜充血等癥狀(zhuang)。有(you)時(shi)出現眼瞼痙攣(luan)及瞼外翻。在取出蟲(chong)(chong)(chong)后(hou)癥狀(zhuang)即消(xiao)失。預后(hou)佳。如果此蟲(chong)(chong)(chong)在眼部(bu)時(shi)間(jian)較(jiao)長,可因此蟲(chong)(chong)(chong)口端角質(zhi)反(fan)復磨擦(ca)角膜引(yin)(yin)起擦(ca)傷,偶(ou)可遺留云翳(yi)而輕度影響視力。
根據病史、蟲(chong)體特(te)征及家畜和(he)蒼(cang)蠅接觸史可與(yu)蠅蛆癥(zheng)相鑒(jian)別(bie),鏡(jing)下作成蟲(chong)形(xing)態(tai)學鑒(jian)定,診斷(duan)并不(bu)難。