湖北省结膜吸吮线虫病原流行区感染情况及中间宿主的纵向调查

目的：探明湖北省结膜吸吮线虫(Tc)的中间宿主及目前流行情况。方法：通过访问了解患者和用生理盐水冲洗法检查犬感染Tc情况，同时还着重调查并检查了冈田氏绕眼果蝇和家蝇，用Tc初产蚴对这两种蝇以喂饲法进行实验感染。结果：调查得知：1975年冬季开展了群众性灭犬工作，使传染源得到控制，至目前无新病例出现。犬感染率由1975年的95％，降至现在的33．3％。检查家蝇200只和冈田氏绕眼果蝇135只，均未发现自然感染。人工感染两种蝇之后20天，检查家蝇112只全部阴性，果蝇84只中7只阳性，实验感染率为10．7％。检得感染期蚴计26条，取其中21条接种兔右眼后第37天虫体发育成熟并产出初产蚴，且从右眼获得Tc成虫3条(雌性2条，雄性1条)。结论：实验证明湖北省Tc的中间宿主是冈田氏绕眼果蝇；纵向调查证明控制养犬可防止人群感染Tc。

Longitudinal investigation and experimental studies on thelaziasis and the intermediate host of Thelazia callipaeda in Guanghua county of Hubei province

Objective To verify houseflies Musca spp. as the intermediate host of Thelazia callipaeda and reveal epidemiological situation of thelaziasis in Hubei province. Methods Dogs eyes infected with T.callipaeda , 400 houseflies Musca and 259 fruitflies Amiota okadai in the city of Laohekou city (previously named as Guanghua county) of Hubei province had been investigated since September 2000. The newborn larvae of T.callipaeda from Laohekou suburbs were fed to houseflies Musca and A.okadai . Larvae used for the study were isolated from female T.callipaeda in laboratory and the susceptibility to houseflies Musca and A.okadai was observed. Results Twenty one dogs from Laohekou, the original epidemic areas of thelaziasis were examined and 7 positive dogs in 21 ( 33.3 %) and 11 T.callipaeda (9 females and 2 males)were identified. From 1975 to 2000, no thelaziasis cases were found through retrospective surveys. These 200 houseflies Musca and 135 A.okadai were disected for examination but showed all negative with the infection. However, newborn larvae of T.callipaeda were used to experimentally infect 112 houseflies Musca and 84 A.okadai and all infected flies were examined on the 20th day after inoculation. As a consequence, houseflies Musca failed to be infected but 9 in 84( 10.7 %) A.okadai were positive. 26 infective larvae of T.callipaeda were obtained and 21 of them were inoculated into right eye of one rabbit.The female worm began to produce newborn larvae in 37 days after infection and 3 adult T.callipaeda (two females and one male) were obtained. Conclusions Fruitflies A.okadai from Hubei province were susceptible to T.callipaeda , which was similar to the result of experimental studies in Anhui province.This survey further confirmed that A.okadai was the intermediate host of T.callipaeda but not houseflies Musca. Infective resouces (adult dogs, for instance) had been under controled thus human thelaziasis had been eradicated in this rural area.