鐵線(xian)(xian)蟲(Gordiacea Von Stebold,1843)又名發形蛇(hair snake),亦稱毛細線(xian)(xian)蟲(hairworm)或戈(ge)爾迪烏斯線(xian)(xian)蟲(gordian worm),土名為銅絲(si)蛇或天絲(si)。
隸(li)屬于(yu)(yu)線(xian)形動物(wu)(wu)門,為(wei)(wei)鐵(tie)(tie)線(xian)蟲(chong)(chong)綱蠕蟲(chong)(chong)的(de)總稱。與醫學有關的(de)蟲(chong)(chong)種(zhong)(zhong)分屬于(yu)(yu)鐵(tie)(tie)線(xian)蟲(chong)(chong)目(Gordioidea)、鐵(tie)(tie)線(xian)蟲(chong)(chong)科(ke)(ke)(Gordiidae)、鐵(tie)(tie)線(xian)蟲(chong)(chong)屬(Gordius )和(he)索(suo)蟲(chong)(chong)科(ke)(ke)的(de)Chordodes, Paragordius和(he)Parachordodes屬等(deng),250~300種(zhong)(zhong)。鐵(tie)(tie)線(xian)蟲(chong)(chong)體細長,馬鬃狀,長可達1米(mi)。成蟲(chong)(chong)在海水或淡水中(zhong)(zhong)自由生活,幼蟲(chong)(chong)寄生在節肢動物(wu)(wu)體內(nei)。國內(nei)分布于(yu)(yu)南北方各省,國外廣(guang)泛分布于(yu)(yu)世界各地。可通(tong)過水源感染人體,引起鐵(tie)(tie)線(xian)蟲(chong)(chong)病。在科(ke)(ke)研中(zhong)(zhong),常作為(wei)(wei)動物(wu)(wu)學的(de)實(shi)驗材料(liao)。
鐵線(xian)蟲見于熱(re)帶(dai)(dai)和溫帶(dai)(dai),在水(shui)中營(ying)自由(you)生(sheng)活,偶能感(gan)染人體(ti),寄生(sheng)于消化道內。成蟲呈(cheng)線(xian)狀,雌雄異體(ti),雌蟲在水(shui)邊產(chan)卵,以蚱蜢、蟑螂和甲蟲等昆(kun)蟲為中間宿主。
大型個體(ti)(ti)。體(ti)(ti)長(chang)為(wei)300-1000毫米,體(ti)(ti)型似細繩狀。與線蟲(chong)的(de)圓(yuan)(yuan)蟲(chong)類相似,但無背線、腹(fu)(fu)線與側(ce)線。前(qian)端(duan)鈍圓(yuan)(yuan),體(ti)(ti)表(biao)角質堅硬,雄體(ti)(ti)末端(duan)分叉(cha),呈倒 "V"字形,分叉(cha)部(bu)分的(de)前(qian)腹(fu)(fu)面為(wei)泄殖孔。消化管幼蟲(chong)期存在(zai),而成蟲(chong)期則退化。雄體(ti)(ti)的(de)精巢和雌(ci)體(ti)(ti)的(de)卵(luan)巢數目多,成對排列于身體(ti)(ti)的(de)兩(liang)側(ce)。生(sheng)活時體(ti)(ti)呈深棕色。
成蟲(chong)(chong)棲息于(yu)河流、池(chi)塘及水溝內(nei),雌體(ti)所產的(de)卵在水內(nei)孵出(chu)幼(you)蟲(chong)(chong),被昆蟲(chong)(chong)或(huo)人類吃進后,通過寄生生活(huo)。當這種蟲(chong)(chong)被大型節(jie)肢動(dong)物如螳螂(lang)、蝗(huang)蟲(chong)(chong)等吞食后,幼(you)蟲(chong)(chong)在這些節(jie)肢動(dong)物體(ti)內(nei)繼續發育(yu),會逐(zhu)漸控制宿(su)(su)主(zhu)的(de)行為,幼(you)蟲(chong)(chong)成長為成蟲(chong)(chong)時,會控制宿(su)(su)主(zhu)尋找水源(yuan)淹死宿(su)(su)主(zhu)后從宿(su)(su)主(zhu)體(ti)內(nei)鉆(zhan)出(chu)。
人類(lei)很容易在水池里和不干凈的(de)水里喝(he)到這些鐵線蟲(chong)(chong)的(de)幼蟲(chong)(chong),喝(he)下去后有一定(ding)幾率感染鐵線蟲(chong)(chong)病(bing),這種病(bing)會使尿(niao)道感染發炎,所以(yi)池塘的(de)水和不干凈的(de)水不能(neng)隨便喝(he)。幼蟲(chong)(chong)在節(jie)肢動(dong)物體(ti)內會誘使寄生體(ti)去尋找水源,所以(yi)水源有節(jie)肢動(dong)物尸體(ti)的(de)時候,不建(jian)議飲用。
成蟲(chong)在水中獨自生活,偶(ou)爾感染(ran)人(ren)體,引起鐵線蟲(chong)病(nematomorphiasis)。本病女性多于(yu)男性。
蟲(chong)體(ti)(ti)(ti)細長(chang),圓(yuan)線形,似鐵絲,黑褐色;長(chang)約(yue)10~50cm,寬約(yue)1~3mm; 頭端(duan)鈍圓(yuan),具有0.5~1mm長(chang)的淡(dan)黃(huang)色區(qu);蟲(chong)體(ti)(ti)(ti)表面有許多(duo)小乳突(tu);雄蟲(chong)尾(wei)部卷曲,末(mo)端(duan)分叉(cha);雌蟲(chong)尾(wei)短尖鈍。蟲(chong)體(ti)(ti)(ti)在體(ti)(ti)(ti)外非常活躍(yue),常有自行打結(jie)的習性。
鐵(tie)線(xian)(xian)蟲(chong)(chong)(chong)(chong)(chong)(chong)成(cheng)蟲(chong)(chong)(chong)(chong)(chong)(chong)生(sheng)(sheng)活于沼澤、池塘、溪(xi)流、溝渠等水體(ti)(ti)中,雌雄交配產卵,卵內幼蟲(chong)(chong)(chong)(chong)(chong)(chong)孵(fu)出(chu)進(jin)入(ru)昆蟲(chong)(chong)(chong)(chong)(chong)(chong)(蚱蜢(locust)、蟋(xi)蟀(Cricket)、蟑螂(Cockroach)、甲蟲(chong)(chong)(chong)(chong)(chong)(chong)(Beetle)等)體(ti)(ti)內發育形成(cheng)稚蟲(chong)(chong)(chong)(chong)(chong)(chong),昆蟲(chong)(chong)(chong)(chong)(chong)(chong)入(ru)水,稚蟲(chong)(chong)(chong)(chong)(chong)(chong)離開(kai)宿主在水中發育為(wei)成(cheng)蟲(chong)(chong)(chong)(chong)(chong)(chong)。人體(ti)(ti)消(xiao)化道(dao)感(gan)染鐵(tie)線(xian)(xian)蟲(chong)(chong)(chong)(chong)(chong)(chong)可(ke)能是通(tong)過接觸(chu)或飲用含有(you)(you)稚蟲(chong)(chong)(chong)(chong)(chong)(chong)的生(sheng)(sheng)水、昆蟲(chong)(chong)(chong)(chong)(chong)(chong)、魚類和螺類或食物而引(yin)起。尿(niao)(niao)路感(gan)染是由于人體(ti)(ti)會陰部(bu)(bu)接觸(chu)有(you)(you)鐵(tie)線(xian)(xian)蟲(chong)(chong)(chong)(chong)(chong)(chong)稚蟲(chong)(chong)(chong)(chong)(chong)(chong)的水體(ti)(ti),經尿(niao)(niao)道(dao)侵入(ru),上行至(zhi)(zhi)膀胱內寄(ji)生(sheng)(sheng)。蟲(chong)(chong)(chong)(chong)(chong)(chong)體(ti)(ti)侵入(ru)人體(ti)(ti)后(hou)可(ke)進(jin)一(yi)步發育至(zhi)(zhi)成(cheng)蟲(chong)(chong)(chong)(chong)(chong)(chong),并可(ke)存活數年。寄(ji)生(sheng)(sheng)泌尿(niao)(niao)道(dao)的患者,以女性(xing)為(wei)多,均(jun)有(you)(you)明顯的泌尿(niao)(niao)道(dao)刺激癥,如下腹部(bu)(bu)劇烈疼痛(tong)、尿(niao)(niao)頻、尿(niao)(niao)急、尿(niao)(niao)痛(tong)、血(xue)尿(niao)(niao)、放射性(xing)腰(yao)痛(tong)、會陰和陰道(dao)炎等,蟲(chong)(chong)(chong)(chong)(chong)(chong)體(ti)(ti)排出(chu)后(hou),癥狀緩解。鐵(tie)線(xian)(xian)蟲(chong)(chong)(chong)(chong)(chong)(chong)寄(ji)生(sheng)(sheng)于消(xiao)化道(dao)所引(yin)起的癥狀一(yi)般不明顯,可(ke)有(you)(you)消(xiao)化不良、腹痛(tong)、腹瀉等表現。亦(yi)見有(you)(you)從眼眶腫物或耳道(dao)檢出(chu)蟲(chong)(chong)(chong)(chong)(chong)(chong)體(ti)(ti)的報告。
診斷(duan)本(ben)病(bing)依據從(cong)尿(niao)(niao)中或糞便中檢獲蟲體。在臨床上若遇到有(you)尿(niao)(niao)道刺(ci)激癥(zheng)狀,久治不愈、而又有(you)生飲或會陰部接(jie)觸過塘(tang)、溝水或潮濕草(cao)地的患(huan)者,應考慮作(zuo)膀胱鏡檢。
鐵線蟲(chong)病盡(jin)管是(shi)一(yi)種(zhong)較(jiao)為罕見的(de)寄生蟲(chong)病,全世界(jie)只有14個國家(jia)有病例(li)報道。但各地(di)因生產(chan)生活接觸自然水體的(de)人群甚多(duo)(duo),其(qi)實際感染人數可(ke)能遠比已報告的(de)例(li)數要多(duo)(duo)。
防(fang)治(zhi)本病的關鍵是(shi)不(bu)(bu)飲不(bu)(bu)潔之水、不(bu)(bu)生(sheng)吃昆(kun)蟲、魚類和螺(luo)類等食物,下水時避免下體與不(bu)(bu)潔水體直(zhi)接接觸。疑(yi)有(you)感染(ran)者(zhe)可口服驅蟲藥促蟲排出,寄生(sheng)于組織(zhi)內者(zhe)應(ying)手術取(qu)蟲。
遠離(li)鐵線蟲疾病的糾纏最好的方法就是不要吃生(sheng)的食(shi)物(wu),魚類,以及螺(luo)類食(shi)物(wu),這些都是不太衛生(sheng)的食(shi)物(wu)。在飲(yin)食(shi)的時候要注意看是否有與不干凈(jing)的水(shui)體有關聯的情況。而且,從臨床方面(mian)數據也能夠看到,被鐵線蟲糾纏的女(nv)性(xing)遠遠多于男性(xing),所以希(xi)望廣大(da)女(nv)性(xing)要重視起來(lai)。