結(jie)膜吸(xi)(xi)吮線(xian)蟲(chong)(chong)(chong)(Thelazia callipaeda(Railliet&Henry,1910)是指吸(xi)(xi)吮科吸(xi)(xi)吮線(xian)蟲(chong)(chong)(chong)屬(shu)的一種線(xian)蟲(chong)(chong)(chong)。主要(yao)寄生于犬(quan)、貓等動物眼結(jie)膜囊(nang)內,也可寄生于人眼,引起結(jie)膜吸(xi)(xi)吮線(xian)蟲(chong)(chong)(chong)病(bing)(thelaziasis)。因本病(bing)多(duo)流行于亞洲(zhou)地區,故又稱(cheng)東方眼蟲(chong)(chong)(chong)病(bing)。成蟲(chong)(chong)(chong)蟲(chong)(chong)(chong)體細長(chang)呈線(xian)狀,圓柱(zhu)形,在人眼結(jie)膜囊(nang)寄居時呈淡紅色,離(li)開人體為(wei)乳白色。蟲(chong)(chong)(chong)體表面具有(you)邊(bian)緣銳利(li)的環形皺褶,側面觀其上下排列(lie)呈鋸齒狀。
成蟲(chong)(chong)(chong)蟲(chong)(chong)(chong)體(ti)細長呈線狀(zhuang),圓(yuan)柱形,在人(ren)眼(yan)結膜囊寄居時呈淡紅(hong)色,離(li)開(kai)人(ren)體(ti)為(wei)乳(ru)白(bai)色。蟲(chong)(chong)(chong)體(ti)表面(mian)(mian)具有邊緣(yuan)銳利的(de)(de)環形皺褶,側(ce)面(mian)(mian)觀其上(shang)下排列呈鋸齒狀(zhuang)。雄蟲(chong)(chong)(chong)大(da)小一(yi)般為(wei)(4.5~15.0)mm×(0.25~0.75)mm,尾端向腹面(mian)(mian)彎曲,由泄(xie)殖腔(qiang)伸出(chu)2根交合刺,長短(duan)及(ji)形狀(zhuang)各異。雌蟲(chong)(chong)(chong)大(da)小為(wei)(6.2~20.0)mm×(0.30~0.85)mm,蟲(chong)(chong)(chong)體(ti)腹面(mian)(mian)尾端有肛(gang)門(men),食管(guan)與腸(chang)結合處(chu)的(de)(de)腹面(mian)(mian)有陰門(men),雌蟲(chong)(chong)(chong)生殖系統發(fa)達,為(wei)雙管(guan)型(xing),近(jin)陰門(men)端子(zi)宮(gong)內的(de)(de)蟲(chong)(chong)(chong)卵(luan)逐(zhu)漸發(fa)育為(wei)盤曲的(de)(de)幼蟲(chong)(chong)(chong),雌蟲(chong)(chong)(chong)直(zhi)接產出(chu)幼蟲(chong)(chong)(chong),為(wei)卵(luan)胎生。雌、雄蟲(chong)(chong)(chong)尾端肛(gang)門(men)周(zhou)圍(wei)均有數對乳(ru)突。食管(guan)陰門(men)幼蟲(chong)(chong)(chong)子(zi)宮(gong)腸(chang)雌蟲(chong)(chong)(chong)頭(tou)部,雄蟲(chong)(chong)(chong)尾部乳(ru)突交合刺。
初產幼蟲(chong)大小為(350~414)μm×(13~19)μm,外被鞘膜,呈(cheng)盤曲狀(zhuang),尾部連接一(yi)膨大氣(qi)球(qiu)狀(zhuang)的鞘膜囊。
成(cheng)蟲(chong)主(zhu)(zhu)要寄生于(yu)犬、貓等動物(wu)的(de)眼(yan)結(jie)膜囊及(ji)淚管內(nei),偶爾(er)寄生于(yu)人(ren)、兔等動物(wu)的(de)眼(yan)部(bu)(bu)。本蟲(chong)屬卵胎生。雌成(cheng)蟲(chong)直(zhi)接產幼(you)蟲(chong)于(yu)結(jie)膜囊內(nei),當中間(jian)(jian)宿(su)(su)主(zhu)(zhu)果蠅舐(shi)吸終宿(su)(su)主(zhu)(zhu)眼(yan)部(bu)(bu)分泌物(wu)時而被吸入蠅體內(nei),經2次蛻皮發育為感(gan)(gan)染(ran)期幼(you)蟲(chong)后進人(ren)蠅的(de)頭部(bu)(bu)口器。當蠅再舐(shi)吸入或其他動物(wu)眼(yan)部(bu)(bu)時,感(gan)(gan)染(ran)期幼(you)蟲(chong)自蠅口器逸出并侵入宿(su)(su)主(zhu)(zhu)眼(yan)部(bu)(bu),經15~20天發育為成(cheng)蟲(chong)。成(cheng)蟲(chong)壽命可(ke)達2年以(yi)上。終宿(su)(su)主(zhu)(zhu):犬、貓(人(ren));中間(jian)(jian)宿(su)(su)主(zhu)(zhu):蠅;感(gan)(gan)染(ran)階段:絲狀蚴;感(gan)(gan)染(ran)方(fang)式:媒介昆蟲(chong)舔舐(shi)眼(yan)部(bu)(bu)。
成(cheng)蟲(chong)寄(ji)生于(yu)人眼(yan)(yan)結膜(mo)(mo)囊(nang)內,以上(shang)結膜(mo)(mo)囊(nang)外(wai)(wai)眥側為多見(jian),也可(ke)(ke)見(jian)于(yu)眼(yan)(yan)前房、淚(lei)(lei)小(xiao)管、淚(lei)(lei)腺及(ji)眼(yan)(yan)瞼、結膜(mo)(mo)下等(deng)(deng)(deng)處。多侵(qin)犯一(yi)側眼(yan)(yan),少數病例可(ke)(ke)雙眼(yan)(yan)感(gan)(gan)染。寄(ji)居蟲(chong)數1條至數條,最多可(ke)(ke)達20余條。由于(yu)蟲(chong)體(ti)表面(mian)銳利(li)環形(xing)皺折的(de)摩擦(ca)、頭端口囊(nang)吸附(fu)作用等(deng)(deng)(deng)的(de)機械性損傷,加(jia)上(shang)蟲(chong)體(ti)分泌物(wu)(wu)、排泄物(wu)(wu)的(de)刺激(ji)及(ji)繼發細菌(jun)感(gan)(gan)染等(deng)(deng)(deng),可(ke)(ke)引起眼(yan)(yan)結膜(mo)(mo)炎癥反應及(ji)肉芽(ya)腫形(xing)成(cheng)。輕者無明(ming)顯癥狀,或有眼(yan)(yan)部異物(wu)(wu)感(gan)(gan)、癢(yang)感(gan)(gan)、刺痛、流淚(lei)(lei)、畏(wei)光、分泌物(wu)(wu)增(zeng)多、疼痛等(deng)(deng)(deng),一(yi)般無視力(li)(li)障礙。嬰幼兒(er)不敢睜眼(yan)(yan),有手抓(zhua)眼(yan)(yan)的(de)動作。家長(chang)可(ke)(ke)發現患兒(er)眼(yan)(yan)球(qiu)有白色細小(xiao)的(de)蟲(chong)體(ti)爬行。重感(gan)(gan)染者可(ke)(ke)發生結膜(mo)(mo)充血,形(xing)成(cheng)小(xiao)潰瘍面(mian),角膜(mo)(mo)混濁、眼(yan)(yan)瞼外(wai)(wai)翻等(deng)(deng)(deng)。如(ru)寄(ji)生在(zai)眼(yan)(yan)前房,可(ke)(ke)有絲狀陰影移(yi)動感(gan)(gan)、睫狀體(ti)充血、房水混濁、眼(yan)(yan)壓升高、瞳(tong)孔擴大(da)、視力(li)(li)下降(jiang)等(deng)(deng)(deng)。如(ru)淚(lei)(lei)小(xiao)管受損,可(ke)(ke)出現淚(lei)(lei)點外(wai)(wai)翻。
診(zhen)斷(duan)主(zhu)要用(yong)鑷子或棉(mian)簽自(zi)眼部(bu)取(qu)出蟲(chong)體(ti),置盛(sheng)有生理(li)鹽水的平皿中,可見蟲(chong)體(ti)蠕(ru)動,用(yong)顯(xian)微鏡檢查蟲(chong)體(ti)特(te)征即可明確(que)診(zhen)斷(duan)。
本(ben)蟲(chong)(chong)主(zhu)要(yao)(yao)分(fen)布(bu)在亞洲。印度、緬甸、菲律賓、泰國、日本(ben)、朝鮮及俄羅斯的(de)(de)(de)(de)遠東地(di)區(qu)(qu)均有病(bing)例(li)(li)報告。我(wo)國的(de)(de)(de)(de)病(bing)例(li)(li)報告始于1917年(nian),為世界最早發現。現已知我(wo)國有25個省、市(shi)、自治區(qu)(qu)有人(ren)體感染(ran)(ran)的(de)(de)(de)(de)病(bing)例(li)(li)報道,其中以江蘇、湖北、安(an)徽(hui)、河(he)南、山東等(deng)地(di)的(de)(de)(de)(de)病(bing)例(li)(li)較(jiao)多(duo)。近年(nian)已證實岡田(tian)繞眼果蠅(Amiota okadai)是(shi)我(wo)國結(jie)膜吸吮(shun)線(xian)蟲(chong)(chong)的(de)(de)(de)(de)中間宿主(zhu),是(shi)本(ben)病(bing)的(de)(de)(de)(de)傳播媒介(jie)。感染(ran)(ran)季(ji)節(jie)以夏秋季(ji)為主(zhu),與蠅類(lei)的(de)(de)(de)(de)季(ji)節(jie)消長(chang)相吻合。感染(ran)(ran)者(zhe)最小3個月(yue),最大者(zhe)88歲,但以嬰幼兒為主(zhu)。本(ben)病(bing)在農(nong)村多(duo)于城(cheng)市(shi)。傳染(ran)(ran)源主(zhu)要(yao)(yao)為家犬,其次是(shi)貓、兔等(deng)動物。根據1982~1991年(nian)的(de)(de)(de)(de)調查,安(an)徽(hui)淮(huai)北重流行地(di)區(qu)(qu)的(de)(de)(de)(de)某(mou)些村鎮家犬的(de)(de)(de)(de)感染(ran)(ran)率(lv)高達76.7%,每犬的(de)(de)(de)(de)感染(ran)(ran)蟲(chong)(chong)數可在30~60條。保蟲(chong)(chong)宿主(zhu)家犬的(de)(de)(de)(de)普遍存在,媒介(jie)中間宿主(zhu)果蠅的(de)(de)(de)(de)廣泛分(fen)布(bu),再加上(shang)幼童(tong)不潔(jie)的(de)(de)(de)(de)眼部衛生,是(shi)結(jie)膜吸吮(shun)線(xian)蟲(chong)(chong)病(bing)流行的(de)(de)(de)(de)主(zhu)要(yao)(yao)因(yin)素。
防(fang)蠅、滅(mie)蠅,搞好環(huan)境(jing)衛生,加強犬(quan)、貓(mao)等動(dong)物管理,注意(yi)個人(ren)衛生,特別注意(yi)眼(yan)部清潔是(shi)預防(fang)感(gan)染的主要措(cuo)施(shi)。治療可(ke)用1%~2%可(ke)卡因或(huo)地卡因溶液滴眼(yan),蟲體受(shou)刺激(ji)從眼(yan)角爬出(chu),或(huo)用鑷子取出(chu)。
病原體最初是(shi)從印度(du)旁遮普的(de)犬眼中發現的(de),以后在美(mei)國、緬甸、菲律賓、朝鮮、印度(du)、日本、泰國、蘇聯、遠東地區等地陸續(xu)有犬體寄生的(de)報道(dao)。我國犬、貓的(de)感染甚為(wei)普遍而(er)嚴(yan)重(zhong)。
人體病(bing)例首先于(yu)1917年發現在(zai)我國。迄今報道已有百例以(yi)上,分布于(yu)河北(bei)、福建、北(bei)京、江(jiang)(jiang)蘇、四(si)川、貴州、河南、安徽、湖南、湖北(bei)、東(dong)(dong)北(bei)、山東(dong)(dong)、天津(jin)、上海、云(yun)南、廣西等省市、自(zi)治區(qu)。其中以(yi)湖北(bei)、山東(dong)(dong)、江(jiang)(jiang)蘇部分地(di)區(qu)為最(zui)(zui)多。人體感染者年齡、性別無特(te)殊性,最(zui)(zui)小4個月(yue),最(zui)(zui)高76歲。
成(cheng)蟲寄生在(zai)結膜囊中,以口囊吸(xi)附在(zai)眼(yan)(yan)(yan)(yan)結膜上,并能(neng)自由(you)移動(dong),體表的皺褶對(dui)患者(zhe)眼(yan)(yan)(yan)(yan)部(bu)造成(cheng)機械性(xing)損傷,加之蟲體分(fen)泌(mi)物和排泄物的化學性(xing)刺激,導致炎癥(zheng)(zheng)反應或(huo)肉芽腫形(xing)成(cheng)。輕者(zhe)可無癥(zheng)(zheng)狀,也可有眼(yan)(yan)(yan)(yan)部(bu)異物感(gan)或(huo)癢(yang)感(gan)、流淚、畏光(guang)、眼(yan)(yan)(yan)(yan)部(bu)分(fen)泌(mi)物增多、結膜充血或(huo)水腫,甚至眼(yan)(yan)(yan)(yan)痛(tong),但視力一(yi)般不受影(ying)響(xiang)。取出蟲體后癥(zheng)(zheng)狀便(bian)可消失。如寄生于眼(yan)(yan)(yan)(yan)前房(fang),可見(jian)絲狀物浮動(dong),房(fang)水混濁(zhuo),眼(yan)(yan)(yan)(yan)壓增高,并可形(xing)成(cheng)小潰瘍(yang),重者(zhe)形(xing)成(cheng)疤痕,造成(cheng)角膜混濁(zhuo)等損害,也可引(yin)起繼發(fa)(fa)性(xing)青(qing)光(guang)眼(yan)(yan)(yan)(yan)、眼(yan)(yan)(yan)(yan)瞼外翻等并發(fa)(fa)癥(zheng)(zheng)。以單(dan)側眼(yan)(yan)(yan)(yan)部(bu)感(gan)染(ran)多見(jian),雙(shuang)眼(yan)(yan)(yan)(yan)感(gan)染(ran)者(zhe)少見(jian)。成(cheng)蟲寄生的數目常為1~10條,最多的一(yi)例多達21條。
可無明顯自(zi)覺癥狀。成蟲在(zai)(zai)(zai)眼(yan)(yan)(yan)結(jie)膜(mo)囊自(zi)由(you)行動(dong),此(ci)蟲體的(de)分(fen)泌物、排泄(xie)物可引(yin)起(qi)局部(bu)刺激癥狀,眼(yan)(yan)(yan)部(bu)有異物感、癢感、畏光、流(liu)淚、分(fen)泌物增多(duo)。如(ru)寄生在(zai)(zai)(zai)前(qian)房可見絲(si)狀物飄動(dong),眼(yan)(yan)(yan)瞼(jian)水腫,結(jie)膜(mo)充血(xue)等(deng)癥狀。有時出(chu)現(xian)眼(yan)(yan)(yan)瞼(jian)痙攣及瞼(jian)外翻。在(zai)(zai)(zai)取出(chu)蟲后(hou)(hou)癥狀即(ji)消(xiao)失。預后(hou)(hou)佳。如(ru)果此(ci)蟲在(zai)(zai)(zai)眼(yan)(yan)(yan)部(bu)時間較長,可因此(ci)蟲口(kou)端角質反復磨擦角膜(mo)引(yin)起(qi)擦傷,偶可遺留云翳而輕度影響視(shi)力。
根據病史、蟲(chong)體特征(zheng)及家畜和蒼(cang)蠅接(jie)觸(chu)史可與蠅蛆癥相鑒別,鏡下作成蟲(chong)形態(tai)學鑒定,診斷并不難(nan)。