結(jie)膜(mo)吸吮(shun)線(xian)(xian)(xian)蟲(chong)(Thelazia callipaeda(Railliet&Henry,1910)是指吸吮(shun)科(ke)吸吮(shun)線(xian)(xian)(xian)蟲(chong)屬的一種線(xian)(xian)(xian)蟲(chong)。主要(yao)寄(ji)生于犬、貓等動(dong)物眼結(jie)膜(mo)囊(nang)內,也可(ke)寄(ji)生于人(ren)眼,引起結(jie)膜(mo)吸吮(shun)線(xian)(xian)(xian)蟲(chong)病(thelaziasis)。因本病多(duo)流行于亞洲地區,故又稱東方眼蟲(chong)病。成蟲(chong)蟲(chong)體(ti)(ti)細(xi)長(chang)呈線(xian)(xian)(xian)狀,圓柱(zhu)形(xing),在人(ren)眼結(jie)膜(mo)囊(nang)寄(ji)居(ju)時(shi)呈淡紅色,離開人(ren)體(ti)(ti)為(wei)乳白色。蟲(chong)體(ti)(ti)表面(mian)具有邊緣銳利的環形(xing)皺褶,側面(mian)觀(guan)其上下排列呈鋸齒狀。
成蟲(chong)(chong)(chong)蟲(chong)(chong)(chong)體細(xi)長呈線狀,圓柱形(xing),在(zai)人(ren)眼結(jie)膜(mo)囊寄(ji)居(ju)時(shi)呈淡紅色,離開人(ren)體為乳(ru)白色。蟲(chong)(chong)(chong)體表面具(ju)有(you)(you)(you)邊緣銳利的環形(xing)皺(zhou)褶,側面觀其上(shang)下排列(lie)呈鋸齒狀。雄(xiong)蟲(chong)(chong)(chong)大小(xiao)一般(ban)為(4.5~15.0)mm×(0.25~0.75)mm,尾(wei)端向腹面彎曲,由泄(xie)殖(zhi)腔伸出2根(gen)交合刺,長短及形(xing)狀各異。雌(ci)蟲(chong)(chong)(chong)大小(xiao)為(6.2~20.0)mm×(0.30~0.85)mm,蟲(chong)(chong)(chong)體腹面尾(wei)端有(you)(you)(you)肛門,食管(guan)與腸結(jie)合處的腹面有(you)(you)(you)陰(yin)門,雌(ci)蟲(chong)(chong)(chong)生(sheng)殖(zhi)系統(tong)發達,為雙管(guan)型,近陰(yin)門端子(zi)宮內的蟲(chong)(chong)(chong)卵(luan)逐漸發育為盤(pan)曲的幼(you)蟲(chong)(chong)(chong),雌(ci)蟲(chong)(chong)(chong)直接產出幼(you)蟲(chong)(chong)(chong),為卵(luan)胎(tai)生(sheng)。雌(ci)、雄(xiong)蟲(chong)(chong)(chong)尾(wei)端肛門周圍均有(you)(you)(you)數對乳(ru)突。食管(guan)陰(yin)門幼(you)蟲(chong)(chong)(chong)子(zi)宮腸雌(ci)蟲(chong)(chong)(chong)頭部,雄(xiong)蟲(chong)(chong)(chong)尾(wei)部乳(ru)突交合刺。
初產幼蟲大(da)小為(350~414)μm×(13~19)μm,外被鞘膜,呈盤曲狀,尾部連接一膨大(da)氣球狀的鞘膜囊。
成(cheng)(cheng)(cheng)蟲(chong)(chong)(chong)(chong)主要寄生(sheng)于犬(quan)、貓等(deng)動物(wu)的(de)眼(yan)結(jie)膜囊及(ji)淚管內,偶爾(er)寄生(sheng)于人、兔等(deng)動物(wu)的(de)眼(yan)部。本蟲(chong)(chong)(chong)(chong)屬卵胎(tai)生(sheng)。雌成(cheng)(cheng)(cheng)蟲(chong)(chong)(chong)(chong)直接產幼(you)蟲(chong)(chong)(chong)(chong)于結(jie)膜囊內,當中間宿(su)主果蠅舐吸(xi)終宿(su)主眼(yan)部分泌物(wu)時而被(bei)吸(xi)入(ru)蠅體內,經2次蛻皮發育(yu)為感染(ran)期(qi)幼(you)蟲(chong)(chong)(chong)(chong)后進人蠅的(de)頭部口(kou)器。當蠅再舐吸(xi)入(ru)或其他動物(wu)眼(yan)部時,感染(ran)期(qi)幼(you)蟲(chong)(chong)(chong)(chong)自(zi)蠅口(kou)器逸(yi)出并侵入(ru)宿(su)主眼(yan)部,經15~20天(tian)發育(yu)為成(cheng)(cheng)(cheng)蟲(chong)(chong)(chong)(chong)。成(cheng)(cheng)(cheng)蟲(chong)(chong)(chong)(chong)壽命可達2年以上(shang)。終宿(su)主:犬(quan)、貓(人);中間宿(su)主:蠅;感染(ran)階段:絲狀蚴;感染(ran)方(fang)式:媒介昆蟲(chong)(chong)(chong)(chong)舔舐眼(yan)部。
成蟲寄生于(yu)(yu)人眼(yan)(yan)(yan)結(jie)膜(mo)囊(nang)內(nei),以上(shang)結(jie)膜(mo)囊(nang)外(wai)(wai)眥側為多見,也可(ke)(ke)見于(yu)(yu)眼(yan)(yan)(yan)前(qian)房、淚(lei)小管、淚(lei)腺及眼(yan)(yan)(yan)瞼(jian)、結(jie)膜(mo)下(xia)等(deng)(deng)處。多侵(qin)犯一側眼(yan)(yan)(yan),少數(shu)病例可(ke)(ke)雙眼(yan)(yan)(yan)感(gan)(gan)染(ran)。寄居蟲數(shu)1條至數(shu)條,最多可(ke)(ke)達(da)20余條。由于(yu)(yu)蟲體(ti)表(biao)面(mian)銳利環形皺折的(de)摩擦、頭(tou)端(duan)口囊(nang)吸(xi)附作用等(deng)(deng)的(de)機(ji)械性損傷(shang),加上(shang)蟲體(ti)分泌(mi)物(wu)、排泄物(wu)的(de)刺激及繼發細(xi)菌感(gan)(gan)染(ran)等(deng)(deng),可(ke)(ke)引起眼(yan)(yan)(yan)結(jie)膜(mo)炎癥反(fan)應及肉(rou)芽腫形成。輕(qing)者無(wu)明(ming)顯癥狀,或有(you)眼(yan)(yan)(yan)部異物(wu)感(gan)(gan)、癢感(gan)(gan)、刺痛、流淚(lei)、畏光、分泌(mi)物(wu)增多、疼痛等(deng)(deng),一般無(wu)視力障(zhang)礙。嬰幼兒不敢睜眼(yan)(yan)(yan),有(you)手抓眼(yan)(yan)(yan)的(de)動作。家長可(ke)(ke)發現患兒眼(yan)(yan)(yan)球有(you)白色(se)細(xi)小的(de)蟲體(ti)爬(pa)行。重感(gan)(gan)染(ran)者可(ke)(ke)發生結(jie)膜(mo)充血,形成小潰瘍(yang)面(mian),角膜(mo)混濁、眼(yan)(yan)(yan)瞼(jian)外(wai)(wai)翻等(deng)(deng)。如寄生在(zai)眼(yan)(yan)(yan)前(qian)房,可(ke)(ke)有(you)絲狀陰影移(yi)動感(gan)(gan)、睫狀體(ti)充血、房水(shui)混濁、眼(yan)(yan)(yan)壓升高、瞳孔(kong)擴大、視力下(xia)降(jiang)等(deng)(deng)。如淚(lei)小管受損,可(ke)(ke)出(chu)現淚(lei)點外(wai)(wai)翻。
診斷主要用(yong)鑷(nie)子或棉簽自(zi)眼部取出蟲體(ti),置盛有生(sheng)理(li)鹽水的平(ping)皿中,可見蟲體(ti)蠕動,用(yong)顯微鏡檢查蟲體(ti)特征即可明確診斷。
本(ben)蟲(chong)(chong)主(zhu)(zhu)(zhu)要分布(bu)在亞洲。印度、緬甸、菲律賓、泰(tai)國、日本(ben)、朝(chao)鮮及俄羅(luo)斯的(de)遠東地區(qu)均有病(bing)(bing)(bing)例(li)報(bao)(bao)告。我國的(de)病(bing)(bing)(bing)例(li)報(bao)(bao)告始于1917年,為(wei)世界(jie)最(zui)早發現。現已知我國有25個(ge)省(sheng)、市(shi)、自治區(qu)有人體(ti)感(gan)染(ran)的(de)病(bing)(bing)(bing)例(li)報(bao)(bao)道,其(qi)中以(yi)江蘇、湖北(bei)、安徽、河南、山東等地的(de)病(bing)(bing)(bing)例(li)較(jiao)多。近年已證實岡(gang)田繞眼(yan)果(guo)蠅(ying)(Amiota okadai)是我國結(jie)膜吸(xi)吮(shun)線(xian)(xian)蟲(chong)(chong)的(de)中間宿(su)主(zhu)(zhu)(zhu),是本(ben)病(bing)(bing)(bing)的(de)傳播媒(mei)介。感(gan)染(ran)季節以(yi)夏秋季為(wei)主(zhu)(zhu)(zhu),與蠅(ying)類的(de)季節消長相(xiang)吻合。感(gan)染(ran)者最(zui)小(xiao)3個(ge)月,最(zui)大者88歲,但以(yi)嬰幼(you)(you)兒為(wei)主(zhu)(zhu)(zhu)。本(ben)病(bing)(bing)(bing)在農(nong)村(cun)(cun)多于城(cheng)市(shi)。傳染(ran)源主(zhu)(zhu)(zhu)要為(wei)家犬,其(qi)次(ci)是貓、兔等動(dong)物。根據1982~1991年的(de)調查,安徽淮北(bei)重流(liu)行地區(qu)的(de)某些(xie)村(cun)(cun)鎮(zhen)家犬的(de)感(gan)染(ran)率高(gao)達76.7%,每犬的(de)感(gan)染(ran)蟲(chong)(chong)數可在30~60條。保(bao)蟲(chong)(chong)宿(su)主(zhu)(zhu)(zhu)家犬的(de)普(pu)遍存在,媒(mei)介中間宿(su)主(zhu)(zhu)(zhu)果(guo)蠅(ying)的(de)廣泛(fan)分布(bu),再加(jia)上幼(you)(you)童不(bu)潔的(de)眼(yan)部衛生(sheng),是結(jie)膜吸(xi)吮(shun)線(xian)(xian)蟲(chong)(chong)病(bing)(bing)(bing)流(liu)行的(de)主(zhu)(zhu)(zhu)要因素。
防(fang)蠅、滅蠅,搞(gao)好環境衛生(sheng),加強犬、貓等動物管理,注意(yi)個人衛生(sheng),特(te)別注意(yi)眼部清潔是預防(fang)感染的主要(yao)措施。治(zhi)療可用1%~2%可卡(ka)(ka)因(yin)或(huo)地(di)卡(ka)(ka)因(yin)溶液滴眼,蟲體(ti)受刺激從眼角(jiao)爬(pa)出,或(huo)用鑷子取出。
病原體最初是從印(yin)度旁遮普(pu)的犬眼中發現(xian)的,以后在美國、緬甸(dian)、菲律賓、朝鮮(xian)、印(yin)度、日本、泰國、蘇(su)聯、遠(yuan)東地區(qu)等地陸續有犬體寄(ji)生的報道。我國犬、貓的感(gan)染甚為普(pu)遍而嚴重。
人(ren)體病例首先(xian)于(yu)1917年(nian)發現在(zai)我國(guo)。迄(qi)今報道已有百例以(yi)上(shang),分(fen)布(bu)于(yu)河北、福(fu)建、北京、江蘇(su)、四川、貴州、河南(nan)、安徽、湖(hu)南(nan)、湖(hu)北、東(dong)(dong)北、山(shan)東(dong)(dong)、天津、上(shang)海、云南(nan)、廣西(xi)等省市、自治區(qu)。其(qi)中以(yi)湖(hu)北、山(shan)東(dong)(dong)、江蘇(su)部分(fen)地區(qu)為最多(duo)。人(ren)體感染(ran)者年(nian)齡、性(xing)別無(wu)特殊性(xing),最小4個月,最高(gao)76歲。
成蟲(chong)寄生(sheng)在(zai)結(jie)膜(mo)(mo)囊中,以(yi)口囊吸附在(zai)眼(yan)(yan)結(jie)膜(mo)(mo)上,并(bing)能(neng)自由移動,體(ti)表(biao)的(de)皺褶對患者(zhe)眼(yan)(yan)部造(zao)成機械(xie)性損(sun)(sun)傷(shang),加之(zhi)蟲(chong)體(ti)分泌物和排泄(xie)物的(de)化學性刺(ci)激,導致炎癥反應或(huo)肉芽腫形成。輕者(zhe)可(ke)(ke)無癥狀(zhuang),也可(ke)(ke)有眼(yan)(yan)部異物感(gan)或(huo)癢感(gan)、流淚、畏光、眼(yan)(yan)部分泌物增多、結(jie)膜(mo)(mo)充(chong)血或(huo)水(shui)腫,甚(shen)至眼(yan)(yan)痛,但視力(li)一般不受影響。取出蟲(chong)體(ti)后癥狀(zhuang)便可(ke)(ke)消失。如寄生(sheng)于眼(yan)(yan)前房,可(ke)(ke)見(jian)絲狀(zhuang)物浮動,房水(shui)混(hun)(hun)濁(zhuo),眼(yan)(yan)壓增高,并(bing)可(ke)(ke)形成小(xiao)潰(kui)瘍,重者(zhe)形成疤痕(hen),造(zao)成角膜(mo)(mo)混(hun)(hun)濁(zhuo)等損(sun)(sun)害,也可(ke)(ke)引起繼發性青光眼(yan)(yan)、眼(yan)(yan)瞼外翻等并(bing)發癥。以(yi)單側(ce)眼(yan)(yan)部感(gan)染多見(jian),雙眼(yan)(yan)感(gan)染者(zhe)少見(jian)。成蟲(chong)寄生(sheng)的(de)數目(mu)常為1~10條(tiao),最多的(de)一例多達21條(tiao)。
可(ke)(ke)無(wu)明顯(xian)自(zi)覺(jue)癥(zheng)(zheng)(zheng)狀(zhuang)。成(cheng)蟲(chong)在(zai)(zai)眼(yan)結膜囊自(zi)由行(xing)動(dong),此蟲(chong)體的分泌(mi)物(wu)、排泄物(wu)可(ke)(ke)引(yin)起局(ju)部刺激癥(zheng)(zheng)(zheng)狀(zhuang),眼(yan)部有異物(wu)感、癢感、畏光、流淚、分泌(mi)物(wu)增多(duo)。如寄生在(zai)(zai)前(qian)房可(ke)(ke)見絲狀(zhuang)物(wu)飄(piao)動(dong),眼(yan)瞼(jian)水(shui)腫,結膜充血等癥(zheng)(zheng)(zheng)狀(zhuang)。有時出(chu)現眼(yan)瞼(jian)痙攣及瞼(jian)外翻(fan)。在(zai)(zai)取(qu)出(chu)蟲(chong)后癥(zheng)(zheng)(zheng)狀(zhuang)即消(xiao)失。預后佳(jia)。如果此蟲(chong)在(zai)(zai)眼(yan)部時間(jian)較長,可(ke)(ke)因此蟲(chong)口端角質反復(fu)磨擦角膜引(yin)起擦傷,偶可(ke)(ke)遺(yi)留云翳而輕度影響視(shi)力。
根(gen)據病史、蟲體(ti)特征及家畜(chu)和(he)蒼(cang)蠅(ying)接觸(chu)史可(ke)與(yu)蠅(ying)蛆癥相鑒別,鏡(jing)下(xia)作(zuo)成蟲形態學鑒定,診斷并不難。