Tchuenté L A, Southgate V R, Théron A, Jourdane J, Ly A, Gryseels B
Department of Zoology, Natural History Museum, South Kensington, London, UK.
Parasitology. 1999 Jun;118 ( Pt 6):595-603. doi: 10.1017/s0031182099004345.
The construction of the Diama dam on the Senegal River and the ensuing ecological changes have led to a massive outbreak of Schistosoma mansoni infection in Northern Senegal, associated with very high intensity of infections, due to extremely intense transmission. The vectorial capacity of Biomphalaria pfeifferi from Ndombo, near Richard-Toll was investigated in order to assess the role of the snail-parasite relationship in this particular epidemiological situation. The results revealed an unusually high compatibility between the Senegalese S. mansoni strain and its local snail intermediate host, B. pfeifferi. The snail infection rate after exposure to a single miracidium per snail was 87%. The cercarial production of infected snails was very high, with a mean total production of 50,456 cercariae per snail. No significant difference was found in the total cercarial output between snails exposed to 1 miracidium and those exposed to 5 miracidia. The increase in the rate of cercarial output was significantly greater in snails exposed to 5 miracidia, but there was a higher mortality in this group. The chronobiological cercarial production pattern showed a peak around mid-day. The implications of these findings on the epidemiology of schistosomiasis in Northern Senegal are discussed.
塞内加尔河上迪亚马大坝的修建及随之而来的生态变化，导致塞内加尔北部曼氏血吸虫感染大规模暴发，由于传播极为强烈，感染强度非常高。为评估在这一特殊流行病学情况下钉螺与寄生虫关系的作用，对来自理查德 - 托尔附近恩东博的费氏双脐螺的传病能力进行了调查。结果显示，塞内加尔曼氏血吸虫菌株与其当地钉螺中间宿主费氏双脐螺之间存在异常高的相容性。每只钉螺暴露于单个毛蚴后的感染率为87%。受感染钉螺的尾蚴产量非常高，每只钉螺平均总产尾蚴50456条。暴露于1个毛蚴的钉螺与暴露于5个毛蚴的钉螺在总尾蚴产量上未发现显著差异。暴露于5个毛蚴的钉螺尾蚴产出率的增加显著更大，但该组死亡率更高。生物钟学尾蚴产出模式显示在中午左右达到峰值。讨论了这些发现对塞内加尔北部血吸虫病流行病学的影响。
