Nuchprayoon Surang, Junpee Alisa, Nithiuthai Suwannee, Chungpivat Sudchit, Suvannadabba Saravudh, Poovorawan Yong
Lymphatic Filariasis Research Unit, Department of Parasitology, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand.
Vet Parasitol. 2006 Sep 10;140(3-4):366-72. doi: 10.1016/j.vetpar.2006.04.003. Epub 2006 May 19.
Lymphatic filariasis has been targeted by the World Health Organization (WHO) to be eliminated by the year 2020. In addition to chemotherapy and vector control, the control of reservoir hosts is necessary for the control program to succeed. Malayan filariasis, caused by Brugia malayi, is endemic in the South of Thailand where domestic cats serve as the major reservoir host. However, in nature, domestic cats also carry B. pahangi, Dirofilaria immitis and D. repens infections and it is difficult to distinguish the different filarial species from each other just by morphology. To assess the burden of filarial parasites, we performed a study on domestic cats in an endemic area of malayan filariasis in the Prasang district, of Surat Thani, a province in Southern Thailand. Together with Giemsa staining and acid phosphatase activity studies, we performed PCR-RFLP analysis on the first internal transcribed spacer (ITS1) region of ribosomal DNA (rDNA). PCR-RFLP with Ase I could clearly differentiate between B. malayi, B. pahangi, D. immitis and D. repens. Out of the 52 cats studied, filarial parasites were identified in 5 (9.5%) cats, of which 4 (7.6%) were B. pahangi and 1 (1.9%) D. immitis. This PCR-RFLP technique detected two additional cats that were not detected by microscopy. The domestic cats are not an important host of B. malayi in this region. We could develop the PCR-RFLP assay test for differentiating filarial nematodes which can be applied to survey human, animal reservoir hosts and mosquito vectors in endemic areas.
世界卫生组织（WHO）已将消除淋巴丝虫病的目标设定为到2020年实现。除了化疗和病媒控制外，控制储存宿主对于控制计划的成功至关重要。由马来布鲁线虫引起的马来丝虫病在泰国南部流行，当地家猫是主要的储存宿主。然而，在自然环境中，家猫还携带彭亨布鲁线虫、犬恶丝虫和匐行恶丝虫感染，仅通过形态学很难区分不同的丝虫种类。为了评估丝虫寄生虫的负担，我们在泰国南部素叻他尼府普拉桑区马来丝虫病流行地区对家猫进行了一项研究。我们结合吉姆萨染色和酸性磷酸酶活性研究，对核糖体DNA（rDNA）的第一个内部转录间隔区（ITS1）进行了PCR-RFLP分析。用Ase I进行的PCR-RFLP可以清楚地区分马来布鲁线虫、彭亨布鲁线虫、犬恶丝虫和匐行恶丝虫。在所研究的52只猫中，在5只（9.5%）猫中鉴定出丝虫寄生虫，其中4只（7.6%）为彭亨布鲁线虫，1只（1.9%）为犬恶丝虫。这种PCR-RFLP技术检测到另外两只通过显微镜未检测到的猫。家猫在该地区不是马来布鲁线虫的重要宿主。我们可以开发用于区分丝虫线虫的PCR-RFLP检测方法，该方法可应用于流行地区的人类、动物储存宿主和蚊媒调查。
