Periago M V, Valero M A, El Sayed M, Ashrafi K, El Wakeel A, Mohamed M Y, Desquesnes M, Curtale F, Mas-Coma S
Departamento de Parasitología, Facultad de Farmacia, Universidad de Valencia, Avenue Vicent Andrés Estellés s/n, 46100 Burjassot-Valencia, Spain.
Infect Genet Evol. 2008 Jan;8(1):51-8. doi: 10.1016/j.meegid.2007.10.001. Epub 2007 Oct 7.
Fasciola gigantica is the main fasciolid species in Africa; however, F. hepatica and F. gigantica overlap in some countries. Egypt deserves mentioning because of the emerging situation of human fascioliasis in the Nile Delta area. The morphometric characteristics of fasciolid adults infecting the main livestock species present in the Nile Delta human endemic area are analyzed through a computer image analysis system (CIAS) on the basis of standardized measurements known to be useful for the differentiation of both fasciolid species. This is the first time that such a study is performed in an African country and, therefore, the results are compared to (i) F. hepatica (European Mediterranean area) and F. gigantica (Burkina Faso) standard populations, i.e. geographical areas where both species do not co-exist, and (ii) F. hepatica and F. gigantica populations from geographical areas where both species do co-exist, including the presence of intermediate forms (Iran). Results indicate the presence of F. hepatica, F. gigantica and intermediate forms (Fasciola sp.) in Egypt for the first time, and demonstrate the usefulness of CIAS for the phenotypic characterization of liver fluke adults from a concrete fascioliasis endemic area. Body roundness, body length over body width, and distance between the ventral sucker and the posterior end of the body provide useful tools for studying inter- and intraspecific morphological diversity in Fasciola adults. The application of these markers to specimens from geographical areas where F. hepatica and F. gigantica co-exist, such as in Egypt and Iran, suggest a strong population-level variation in Fasciola adult morphology.
巨片形吸虫是非洲主要的片形科吸虫物种；然而，肝片形吸虫和巨片形吸虫在一些国家存在重叠分布。由于尼罗河三角洲地区出现了人类片形吸虫病疫情，埃及值得一提。基于已知对区分这两种片形科吸虫物种有用的标准化测量方法，通过计算机图像分析系统（CIAS）对感染尼罗河三角洲人类流行区主要家畜物种的片形科吸虫成虫的形态特征进行了分析。这是首次在非洲国家开展此类研究，因此，将结果与（i）肝片形吸虫（欧洲地中海地区）和巨片形吸虫（布基纳法索）的标准种群进行比较，即这两个物种不存在共存的地理区域，以及（ii）来自这两个物种共存的地理区域（包括中间形态的存在情况，如伊朗）的肝片形吸虫和巨片形吸虫种群进行比较。结果首次表明埃及存在肝片形吸虫、巨片形吸虫和中间形态（片形吸虫属），并证明了CIAS对于来自具体片形吸虫病流行区的肝吸虫成虫表型特征分析的有用性。身体圆润度、体长与体宽之比以及腹吸盘与身体后端之间的距离为研究片形吸虫成虫种间和种内形态多样性提供了有用工具。将这些标记应用于来自肝片形吸虫和巨片形吸虫共存的地理区域（如埃及和伊朗）的标本，表明片形吸虫成虫形态在种群水平上存在很大差异。
