Ripert C
Laboratoire de parasitologie, Université de Bordeaux II, 146 rue Léo Saignat, B.P.37, 33076 Bordeaux, France.
Bull Soc Pathol Exot. 2003 Aug;96(3):183-6.
The species name of Schistosoma intercalatum, Fischer 1934 is linked to the shape and the size of his eggs, which are intermediate between those of S. haematobium and S. bovis. S. intercalatum is the instrument of an intestinal form of schistosomiasis looking like the form induced by S. mansoni but characterized by a low location of the lesions, mainly situated at the rectum and sigmoid level. The spreading area of S. intercalatum is bound to Central Africa. The foci are often urban and of a size limited to a town district. Bulinus forskalii is the intermediate host mostly involved in transmitting S. intercalatum lower Guinea strain, which is the strain found in the largest number of foci. B. crystallinus too transmits the parasite in the area of Gamba in Gabon. The Central Basin congolese strain of S. intercalatum is transmitted by Bulinus globosus. The houses where inhabitants are voiding eggs of S. intercalatum are just in front of the river bank or stream which are snails'breeding places. S. intercalatum is expending at the present time because of the development of built-up areas which are characterized by a disorganized town-planning. The disease is due to the high faecal pollution of the environment, causing a contamination of the urban hydrographic network which is the setting of schistosomiasis transmission. Although primely linked to the forest area, S. intercalatum is spreading with deforestation. Coming from the savannah area, S. haematobium is now invading the forest area, entering into competition with S. intercalatum. But since Bulinus acting as intermediate hosts of S. haematobium are more heliophilous than Bulinus transmitting S. intercalatum, urinary schistosomiasis has a tendency to supplant recto-sigmoidal schistosomiasis, especially in foci where hybridization between the two species of schistosomes is occurring.
间插血吸虫（Schistosoma intercalatum）的种名由菲舍尔于1934年确定，其与该血吸虫虫卵的形状和大小有关，这些虫卵的特征介于埃及血吸虫（S. haematobium）和牛血吸虫（S. bovis）的虫卵之间。间插血吸虫是肠道血吸虫病的病原体，其引发的病症与曼氏血吸虫（S. mansoni）引发的类似，但病变位置较低，主要位于直肠和乙状结肠水平。间插血吸虫的传播区域局限于中非。其疫源地通常在城市，且规模往往仅限于一个城区。福氏泡螺（Bulinus forskalii）是传播间插血吸虫下几内亚株的主要中间宿主，该毒株在大多数疫源地被发现。晶泡螺（B. crystallinus）也在加蓬的甘巴地区传播这种寄生虫。间插血吸虫的刚果中央盆地株由球泡螺（Bulinus globosus）传播。居民排出间插血吸虫虫卵的房屋就在河岸或溪流前方，而这些地方是蜗牛的繁殖场所。由于城镇规划混乱的建成区不断发展，间插血吸虫目前正在扩散。该疾病是由于环境中粪便污染严重，导致城市水系受到污染，而城市水系正是血吸虫病传播的传播传播的环境。尽管间插血吸虫最初与森林地区相关，但随着森林砍伐它也在扩散。来自草原地区的埃及血吸虫如今正在侵入森林地区，与间插血吸虫形成竞争。但是，由于作为埃及血吸虫中间宿主的泡螺比传播间插血吸虫的泡螺更喜阳（向阳性更强），泌尿血吸虫病有取代直肠乙状结肠血吸虫病的趋势，尤其是在两种血吸虫发生杂交的疫源地。
