Wang Zeng-xian, Hu Yue, Shen Ji-long, Wang Ke-can, Wang Hong-yan, Jiang Bao-ling, Zhao Peng, Wang Zhi-cheng, Ding Wei, Wang Feng, Xia Xiu-fang
Department of Parasitology, Anhui Medical University, Hefei 230032, China.
Zhonghua Liu Xing Bing Xue Za Zhi. 2003 Jul;24(7):588-90.
To verify houseflies Musca spp. as the intermediate host of Thelazia callipaeda and reveal epidemiological situation of thelaziasis in Hubei province.
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.
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 dissected 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.
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 resources (adult dogs, for instance) had been under controlled thus human thelaziasis had been eradicated in this rural area.
验证家蝇为结膜吸吮线虫的中间宿主，并揭示湖北省结膜吸吮线虫病的流行状况。
自2000年9月起，对湖北省老河口市（原光化县）400只家蝇、259只果蝇以及感染结膜吸吮线虫的犬眼进行调查。将采自老河口郊区结膜吸吮线虫的新生幼虫投喂给家蝇和果蝇。用于研究的幼虫在实验室从雌性结膜吸吮线虫体内分离获得，并观察家蝇和果蝇对其的易感性。
对来自结膜吸吮线虫病原疫区老河口的21只犬进行检查，21只中有7只阳性犬（33.3%），共检出11条结膜吸吮线虫（9只雌虫和2只雄虫）。通过回顾性调查，1975年至2000年期间未发现结膜吸吮线虫病病例。解剖检查200只家蝇和135只果蝇，均未发现感染。然而，用结膜吸吮线虫新生幼虫对112只家蝇和84只果蝇进行实验感染，接种后第20天对所有感染果蝇进行检查。结果家蝇未被感染，但84只果蝇中有9只（10.7%）呈阳性。获得26条结膜吸吮线虫感染性幼虫，将其中21条接种到1只家兔右眼。感染后37天雌虫开始产出新生幼虫，获得3条成虫（2只雌虫和1只雄虫）。
湖北省果蝇对结膜吸吮线虫易感，这与安徽省的实验研究结果相似。本次调查进一步证实果蝇是结膜吸吮线虫的中间宿主，而家蝇不是。感染源（如成年犬）已得到控制，因此该农村地区已根除人体结膜吸吮线虫病。
