Medical Parasitology Department, Faculty of Medicine, Alexandria University, Alexandria, Egypt.
J Biosci. 2013 Sep;38(3):665-72. doi: 10.1007/s12038-013-9329-4.
The African species of Biomphalaria appeared as a result of the relatively recent west-to-east trans-Atlantic dispersal of the Biomphalaria glabrata-like taxon. In Egypt, Biomphalaria alexandrina is the intermediate host for Schistosoma mansoni. Biomphalaria alexandrina originated in the area between Alexandria and Rosetta and has historically been confined to the Nile Delta. Schistosoma mansoni reached Egypt via infected slaves and baboons from the Land of Punt through migrations that occurred as early as the Vth Dynasty. The suggestion of the presence of Schistosoma mansoni infection in Lower Egypt during Pharaonic times is discussed despite the fact that that there is no evidence of such infection in Egyptian mummies. It is only recently that Biomphalaria alexandrina colonized the Egyptian Nile from the Delta to Lake Nasser. This change was likely due to the construction of huge water projects, the development of new water resources essential for land reclamation projects and the movement of refugees from the Suez Canal zone to the Delta and vice versa. The situation with respect to Biomphalaria in Egypt has become complicated in recent years by the detection of Biomphalaria glabrata and a hybrid between both species; however, follow-up studies have demonstrated the disappearance of such species within Egypt. The National Schistosoma Control Program has made great strides with respect to the eradication of schistosoma; however, there has unfortunately been a reemergence of Schistosoma mansoni resistant to praziquantel. There are numerous factors that may influence the prevalence of snails in Egypt, including the construction of water projects, the increase in reclaimed areas, global climate change and pollution. Thus, continued field studies in addition to the cooperation of several scientists are needed to obtain an accurate representation of the status of this species. In addition, the determination of the genome sequence for Biomphalaria alexandrina and the use of modern technology will allow for the study of the host-parasite relationship at a molecular level.
非洲的玻氏血吸虫中间宿主种类是生物型玻氏血吸虫的一个分支，由相对较近的跨大西洋西向东扩散而产生。在埃及，亚历山大蜗牛是曼氏血吸虫的中间宿主。亚历山大蜗牛起源于亚历山大和罗塞塔之间的地区，历史上一直局限于尼罗河三角洲。曼氏血吸虫通过受感染的奴隶和来自蓬特之地的狒狒从第五王朝时期开始的迁徙进入埃及。尽管在埃及木乃伊中没有发现这种感染的证据，但讨论了在法老时代下埃及存在曼氏血吸虫感染的可能性。直到最近，亚历山大蜗牛才从三角洲殖民到纳赛尔湖。这种变化可能是由于大型水利工程的建设、开垦土地项目所需的新水资源的开发以及从苏伊士运河区向三角洲和反之的难民流动所导致的。近年来，由于发现了光滑双脐螺和这两个物种的杂交种，埃及的玻氏血吸虫情况变得复杂了。然而，后续研究表明，这些物种已在埃及消失。国家血吸虫病控制计划在消灭血吸虫方面取得了巨大进展；然而，不幸的是，出现了对 praziquantel 具有抗性的曼氏血吸虫。有许多因素可能影响埃及蜗牛的流行，包括水利工程的建设、开垦面积的增加、全球气候变化和污染。因此，除了需要几位科学家的合作之外，还需要进行持续的实地研究，以准确了解该物种的现状。此外，确定亚历山大蜗牛的基因组序列并利用现代技术将允许在分子水平上研究宿主-寄生虫关系。
