鐵線蟲(chong)(Gordiacea Von Stebold,1843)又名發形(xing)蛇(hair snake),亦(yi)稱毛細線蟲(chong)(hairworm)或戈爾迪烏斯(si)線蟲(chong)(gordian worm),土名為銅絲蛇或天絲。
隸(li)屬于(yu)線形動物(wu)門(men),為鐵(tie)線蟲(chong)(chong)(chong)綱蠕蟲(chong)(chong)(chong)的(de)總稱。與醫學(xue)有(you)關的(de)蟲(chong)(chong)(chong)種分(fen)屬于(yu)鐵(tie)線蟲(chong)(chong)(chong)目(Gordioidea)、鐵(tie)線蟲(chong)(chong)(chong)科(Gordiidae)、鐵(tie)線蟲(chong)(chong)(chong)屬(Gordius )和索蟲(chong)(chong)(chong)科的(de)Chordodes, Paragordius和Parachordodes屬等(deng),250~300種。鐵(tie)線蟲(chong)(chong)(chong)體細長,馬鬃狀,長可(ke)達1米。成蟲(chong)(chong)(chong)在海水(shui)或淡水(shui)中(zhong)自由生(sheng)活,幼蟲(chong)(chong)(chong)寄生(sheng)在節(jie)肢動物(wu)體內(nei)。國(guo)(guo)內(nei)分(fen)布于(yu)南(nan)北方各省,國(guo)(guo)外廣泛分(fen)布于(yu)世界各地。可(ke)通過水(shui)源(yuan)感染人(ren)體,引起鐵(tie)線蟲(chong)(chong)(chong)病。在科研中(zhong),常作為動物(wu)學(xue)的(de)實驗材料。
鐵線蟲見于熱帶和溫帶,在水中(zhong)營自由生活,偶能(neng)感(gan)染人體,寄生于消化道內。成蟲呈(cheng)線狀,雌雄異體,雌蟲在水邊產卵(luan),以(yi)蚱蜢(meng)、蟑(zhang)螂(lang)和甲蟲等昆蟲為(wei)中(zhong)間宿(su)主。
大型個體。體長為300-1000毫米(mi),體型似細繩狀。與線(xian)(xian)蟲(chong)(chong)(chong)的(de)圓(yuan)蟲(chong)(chong)(chong)類相似,但(dan)無背線(xian)(xian)、腹線(xian)(xian)與側線(xian)(xian)。前端(duan)鈍圓(yuan),體表角質堅硬(ying),雄(xiong)體末(mo)端(duan)分(fen)叉(cha),呈倒 "V"字形(xing),分(fen)叉(cha)部分(fen)的(de)前腹面為泄殖孔(kong)。消化(hua)管幼蟲(chong)(chong)(chong)期存在,而成(cheng)蟲(chong)(chong)(chong)期則退化(hua)。雄(xiong)體的(de)精巢和雌體的(de)卵(luan)巢數目(mu)多,成(cheng)對(dui)排列(lie)于(yu)身體的(de)兩側。生活時體呈深棕(zong)色。
成(cheng)蟲(chong)棲息于河流(liu)、池(chi)塘及水溝內(nei)(nei),雌體所產的(de)卵在(zai)水內(nei)(nei)孵出幼(you)蟲(chong),被昆(kun)蟲(chong)或人(ren)類吃進(jin)后,通過寄生生活。當這(zhe)種蟲(chong)被大型節肢動(dong)物如(ru)螳螂(lang)、蝗蟲(chong)等(deng)吞食后,幼(you)蟲(chong)在(zai)這(zhe)些(xie)節肢動(dong)物體內(nei)(nei)繼續(xu)發育,會(hui)逐漸控制(zhi)宿(su)主的(de)行為,幼(you)蟲(chong)成(cheng)長為成(cheng)蟲(chong)時(shi),會(hui)控制(zhi)宿(su)主尋找水源淹死宿(su)主后從宿(su)主體內(nei)(nei)鉆出。
人類很容易在水(shui)(shui)池(chi)里和不干凈(jing)的(de)水(shui)(shui)里喝(he)(he)到這些(xie)鐵線蟲的(de)幼蟲,喝(he)(he)下去(qu)后有一定幾率感染鐵線蟲病,這種病會使(shi)尿道感染發炎,所(suo)以池(chi)塘的(de)水(shui)(shui)和不干凈(jing)的(de)水(shui)(shui)不能隨便喝(he)(he)。幼蟲在節(jie)肢(zhi)動物(wu)體(ti)內會誘使(shi)寄生(sheng)體(ti)去(qu)尋(xun)找水(shui)(shui)源,所(suo)以水(shui)(shui)源有節(jie)肢(zhi)動物(wu)尸體(ti)的(de)時候,不建(jian)議飲用。
成蟲在水中獨自生活,偶爾感染人體(ti),引(yin)起鐵(tie)線(xian)蟲病(bing)(nematomorphiasis)。本病(bing)女性多于(yu)男性。
蟲(chong)體(ti)(ti)細長,圓(yuan)線(xian)形(xing),似鐵絲,黑褐色;長約10~50cm,寬約1~3mm; 頭端(duan)(duan)鈍(dun)圓(yuan),具(ju)有(you)0.5~1mm長的淡黃色區;蟲(chong)體(ti)(ti)表面有(you)許多小乳突;雄蟲(chong)尾部卷曲(qu),末端(duan)(duan)分叉;雌蟲(chong)尾短尖鈍(dun)。蟲(chong)體(ti)(ti)在體(ti)(ti)外非常活躍,常有(you)自(zi)行打結的習性。
鐵(tie)線(xian)蟲(chong)(chong)(chong)(chong)成蟲(chong)(chong)(chong)(chong)生(sheng)活于(yu)沼澤(ze)、池塘、溪流、溝渠等水體(ti)(ti)中,雌雄交配產卵,卵內幼蟲(chong)(chong)(chong)(chong)孵出(chu)進入(ru)昆蟲(chong)(chong)(chong)(chong)(蚱蜢(locust)、蟋(xi)蟀(Cricket)、蟑螂(Cockroach)、甲蟲(chong)(chong)(chong)(chong)(Beetle)等)體(ti)(ti)內發(fa)育形(xing)成稚(zhi)(zhi)(zhi)蟲(chong)(chong)(chong)(chong),昆蟲(chong)(chong)(chong)(chong)入(ru)水,稚(zhi)(zhi)(zhi)蟲(chong)(chong)(chong)(chong)離開宿(su)主在水中發(fa)育為(wei)成蟲(chong)(chong)(chong)(chong)。人(ren)(ren)體(ti)(ti)消化(hua)道感(gan)染(ran)鐵(tie)線(xian)蟲(chong)(chong)(chong)(chong)可能(neng)是通過接觸或飲用(yong)含有(you)(you)稚(zhi)(zhi)(zhi)蟲(chong)(chong)(chong)(chong)的(de)生(sheng)水、昆蟲(chong)(chong)(chong)(chong)、魚(yu)類和螺類或食物(wu)而(er)引起。尿(niao)路感(gan)染(ran)是由(you)于(yu)人(ren)(ren)體(ti)(ti)會陰(yin)部接觸有(you)(you)鐵(tie)線(xian)蟲(chong)(chong)(chong)(chong)稚(zhi)(zhi)(zhi)蟲(chong)(chong)(chong)(chong)的(de)水體(ti)(ti),經尿(niao)道侵(qin)入(ru),上行至(zhi)膀胱內寄(ji)生(sheng)。蟲(chong)(chong)(chong)(chong)體(ti)(ti)侵(qin)入(ru)人(ren)(ren)體(ti)(ti)后(hou)可進一(yi)步(bu)發(fa)育至(zhi)成蟲(chong)(chong)(chong)(chong),并可存活數年。寄(ji)生(sheng)泌尿(niao)道的(de)患者(zhe),以女性為(wei)多,均有(you)(you)明顯(xian)的(de)泌尿(niao)道刺(ci)激癥(zheng),如(ru)下腹部劇(ju)烈(lie)疼痛、尿(niao)頻、尿(niao)急、尿(niao)痛、血(xue)尿(niao)、放射性腰痛、會陰(yin)和陰(yin)道炎等,蟲(chong)(chong)(chong)(chong)體(ti)(ti)排出(chu)后(hou),癥(zheng)狀緩解。鐵(tie)線(xian)蟲(chong)(chong)(chong)(chong)寄(ji)生(sheng)于(yu)消化(hua)道所引起的(de)癥(zheng)狀一(yi)般不(bu)明顯(xian),可有(you)(you)消化(hua)不(bu)良、腹痛、腹瀉等表現。亦見有(you)(you)從眼眶腫物(wu)或耳道檢出(chu)蟲(chong)(chong)(chong)(chong)體(ti)(ti)的(de)報告(gao)。
診斷本病依據從尿(niao)中(zhong)或(huo)糞便(bian)中(zhong)檢獲蟲體。在臨床上(shang)若遇到有尿(niao)道刺激癥狀,久治不愈、而(er)又有生(sheng)飲(yin)或(huo)會陰部接(jie)觸過(guo)塘、溝水或(huo)潮濕草地(di)的患者,應(ying)考慮作(zuo)膀胱鏡檢。
鐵線蟲病盡管是一(yi)種較為罕見的(de)(de)寄生(sheng)(sheng)蟲病,全世界(jie)只有14個國家有病例報(bao)道。但(dan)各地(di)因(yin)生(sheng)(sheng)產生(sheng)(sheng)活接觸(chu)自然(ran)水體的(de)(de)人(ren)群甚多,其實際(ji)感(gan)染人(ren)數可能遠比已報(bao)告的(de)(de)例數要多。
防治本病(bing)的關(guan)鍵是不(bu)飲不(bu)潔之水、不(bu)生(sheng)吃昆蟲(chong)、魚類和螺類等食物,下水時避免下體(ti)與不(bu)潔水體(ti)直接接觸。疑有感染者可(ke)口服驅蟲(chong)藥(yao)促蟲(chong)排(pai)出,寄生(sheng)于組織(zhi)內者應手術取蟲(chong)。
遠離鐵線(xian)蟲疾(ji)病的(de)糾纏最好的(de)方法(fa)就(jiu)是不(bu)要吃(chi)生(sheng)的(de)食(shi)(shi)物,魚類,以(yi)及螺(luo)類食(shi)(shi)物,這些都是不(bu)太衛生(sheng)的(de)食(shi)(shi)物。在(zai)飲食(shi)(shi)的(de)時候要注(zhu)意看(kan)是否有(you)(you)與不(bu)干凈的(de)水體有(you)(you)關聯的(de)情況(kuang)。而且(qie),從臨(lin)床方面數據(ju)也能夠看(kan)到,被鐵線(xian)蟲糾纏的(de)女性遠遠多于男性,所以(yi)希望(wang)廣大女性要重視起來。