Doanh Pham N, Nawa Yukifumi
Institute of Ecology and Biological Resources, Viet Nam Academy of Science and Technology, 18 Hoang Quoc Viet, Cau Giay, Hanoi, Viet Nam
Research Affairs Office, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.
Trans R Soc Trop Med Hyg. 2016 Jan;110(1):13-20. doi: 10.1093/trstmh/trv103.
Clonorchis sinensis and Opisthorchis viverrini are clinically important small liver flukes because of their known association with development of cholangiocarcinoma. In Vietnam, high prevalence of C. sinensis infection in humans was previously reported in northern provinces, and O. viverrini infection has been detected in several central provinces. However, diagnosis of C. sinensis and O. viverrini infections in the past was merely based on faecal egg examination. This method alone can lead to misidentification at the species level because of morphological similarity between the eggs of these liver flukes and minute intestinal trematodes of the family Heterophyidae. In fact, recent surveys in Vietnam revealed that infection with several minute intestinal flukes, such as Haplorchis pumilio and H. taichui, are much more common than infection with C. sinensis or O. viverrini, and they often co-infect humans. Thus, previously reported prevalence of small liver fluke infection in Vietnam was likely over-estimated due to mis identification of parasites in copro-parasitological examinations. In addition, there is some confusion about identification of cercariae, metacercariae and also adults of C. sinensis and O. viverrini in intermediate and definitive hosts. The aim of this review is, therefore, to draw realistic pictures of the past and present scientific reports on the epidemiology and biology of C. sinensis and Opisthorchis spp. infection in Vietnam.
华支睾吸虫和麝猫后睾吸虫是具有临床重要性的小型肝吸虫，因为它们与胆管癌的发生有关。在越南，以前有报道称北部省份人群中华支睾吸虫感染率很高，并且在中部几个省份检测到了麝猫后睾吸虫感染。然而，过去对华支睾吸虫和麝猫后睾吸虫感染的诊断仅仅基于粪便虫卵检查。由于这些肝吸虫的虫卵与异形科微小肠吸虫的虫卵在形态上相似，仅靠这种方法可能会导致物种水平的错误鉴定。事实上，越南最近的调查显示，几种微小肠吸虫，如微小哈氏吸虫和泰国哈氏吸虫的感染比华支睾吸虫或麝猫后睾吸虫的感染更为常见，而且它们常常同时感染人类。因此，由于在粪便寄生虫学检查中对寄生虫的错误鉴定，越南以前报道的小型肝吸虫感染率可能被高估了。此外，在中间宿主和终宿主中，对华支睾吸虫和麝猫后睾吸虫的尾蚴、囊蚴以及成虫的鉴定也存在一些混淆。因此，本综述的目的是描绘出关于越南华支睾吸虫和后睾属吸虫感染的流行病学和生物学的过去和现在科学报告的真实情况。
