Yousif F, el-Emam M, Abdel-Kader A, el-Din A S, el-Hommossany K, Shiff C
Department of Environmental Research and Medical Malacology, Theodor Bilharz Research Institute, Imbaba, Egypt.
J Egypt Soc Parasitol. 1998 Dec;28(3):915-28.
Two newly reclaimed areas located west & east of Suez Canal, namely El Manayef area and El Morra area, were studied for patterns of distribution and population seasonal fluctuation of Biomphalaria alexandrina and Bulinus truncatus, the intermediate host snails of Schistosoma mansoni and S. haematobium, respectively. In this study Geographic Information System (GIS) techniques were utilized for producing maps and analyzing the results. Habitats of the two vector snail species were categorized into suitability levels depending on the frequency with which snails were collected over a 12 months period. Data obtained from the most suitable habitats were only used for studying the seasonal fluctuation of snail population. The results showed that both study areas were almost similar in major physico-chemical parameters. However, oxygen content in canals was higher than in drains and conductivity was higher in drains than in canals. As regards snail distribution and density, most snails of both considered species were clustering in much fewer numbers of sites, more pronouncedly in the case of Biomphalaria than Bulinus. Population density of snails was significantly higher in El-Manayef area than in El-Morra area and in canals than in drains. Both species exhibited 2 population peaks/year, the peaks of Biomphalaria were in March-April & August in both study areas, while for Bulinus these peaks occurred in March-May and August in El-Manayef area and in May and March, respectively, in El-Morra area.
对位于苏伊士运河东西两侧的两个新垦地区，即埃尔马纳耶夫地区和埃尔莫拉地区，进行了研究，以了解亚历山大双脐螺和截形小泡螺的分布模式和种群季节波动情况，这两种螺分别是曼氏血吸虫和埃及血吸虫的中间宿主螺。在本研究中，利用地理信息系统（GIS）技术制作地图并分析结果。根据在12个月期间采集到的螺的频率，将这两种传播媒介螺的栖息地分为适宜程度等级。仅将从最适宜栖息地获得的数据用于研究螺种群的季节波动。结果表明，两个研究区域在主要理化参数方面几乎相似。然而，运河中的含氧量高于排水渠，排水渠中的电导率高于运河。关于螺的分布和密度，两种螺的大多数都聚集在数量少得多的地点，亚历山大双脐螺的情况比截形小泡螺更明显。埃尔马纳耶夫地区的螺种群密度明显高于埃尔莫拉地区，运河中的高于排水渠中的。两种螺每年均出现2个种群高峰，亚历山大双脐螺的高峰在两个研究区域均出现在3 - 4月和8月，而截形小泡螺在埃尔马纳耶夫地区的高峰出现在3 - 5月和8月，在埃尔莫拉地区分别出现在5月和3月。
