SIMULIUM-DAMNOSUM AND ITS RELATION TO ONCHOCERCIASIS IN THE ANGLO-EGYPTIAN SUDAN
SIMULIUM-DAMNOSUM AND ITS RELATION TO ONCHOCERCIASIS IN THE ANGLO-EGYPTIAN SUDAN
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DOI：
10.1017/s0007485300026705
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发表时间：
1953-01-01
影响因子：
1.9
通讯作者：
LEWIS, DJ
中科院分区：
文献类型：
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作者：
LEWIS, DJ
回顾了先前关于 S.damnosum 盘尾丝虫病问题的研究。地图显示了该地区。 S.damnosum 和人类盘尾丝虫病。方法描述如下。用于收集、处理、安装、保存活的成虫、解剖、保存、固定、切片 S.damnosum，以及研究盘尾丝虫的感染率和生活史。最近出现的苍蝇可以通过笼头的透明度、丰富的脂肪体的存在和旧的围食膜的不存在来检测。围营养膜是完全包围摄入的血液的几丁质包膜。它24小时保持不间断。或更多。当摄入大量微丝蚴时，它们似乎会阻止膜的完成，从而使血液迅速流至后肠。主要繁殖季节在 s。苏丹是多雨的季节，而在北方，则处于旱季。在南方，成虫在雨季广泛分布，但在旱季仅限于灌木丛中。 S.damnosum 可能可以随风飞行或飘移 30 公里。或更多。雌性摄入的物质包括人类血液和其他组织颗粒、植物糖、盘旋线虫和持久棘唇线虫的微丝蚴、砂砾颗粒，有时还有花粉粒。当卵巢发育时，苍蝇每两三天叮咬的次数不会超过一次。它们在不同的条件下咬人，但在茂密的草丛中咬人的情况比在露天的情况要少。在中等黑暗的建筑物中很少有苍蝇叮咬。咬人行为在日出前开始，持续到黄昏后，下午增加。一只雌性可产下 500 多个蛋。除盘旋线虫外，还发现了15种寄生虫：原生动物5种、线虫6种、膜翅纲蚴幼虫1种、螨虫2种和身份不明的尸体，常见的是一种sp。 Mermis 和 Planidium。人类盘尾丝虫病发生在南部河流到达大沼泽之前的中游地区。它的分布范围远不如 S.damnosum 那样广泛，而 S.damnosum 则在没有疾病的情况下发生。苏丹及 s.溪流。感染区域虽然很大，但相对不重要且生产力低下；没有城镇受到严重影响。据报道，失明率约为人口的 1% 至 10%。 S.damnosum 被认为是唯一的媒介。下雨期间在姆沃洛。平均。苍蝇发育中幼虫的感染率为12%。观察到的最高感染率为 36%，其中头部感染率为 8.5%。受感染的苍蝇被发现距离苏河 33 公里。传播主要发生在雨季，因为雨季蝇类分布广泛，盘旋线虫的感染阶段也很常见。摄入的微丝蚴数量远多于完成发育的幼虫数量。大多数微丝蚴被围食膜包围并留在那里直至死亡。当膜形成时，一些残留在中肠的管状部分中，并且显然有一些进入周围营养间隙，穿透中肠扩张部分的上皮并进入胸肌。实际控制措施尚不清楚；为了保护，建议使用稍微黑暗的建筑物、防护服和驱虫剂邻苯二甲酸二甲酯。
Previous works on the S. damnosum onchocerciasis problem are reviewed. A map shows the distr. of S. damnosum and human onchocerciasis. Methods are descr. for collecting, handling, mounting, keeplng live adults, dissecting, preserving, fixing, section-cutting of S. damnosum, and for studying infection rates and life-history of Onchocerca volvulus. Recently emerged flies can be detected by the clarity of the halteres, the presence of abundant fat bodies and the absence of an old peritrophic membrane. The peritrophic membrane is a chitinous envelope completely surrounding ingested blood. It remains unbroken for 24 hrs. or more. When large numbers of microfilariae are ingested they appear to prevent the completion of the membrane so that blood quickly passes to the hind-gut. The main breeding season in the s. Sudan is the rains, and in the north, in the dry season. In the south adults are widespread during the rains but restricted to patches of bush in the dry season. S. damnosum can probably fly or drift on the wind for 30 km. or more. Material ingested by the femalc includes human blood and particles of other tissue, plant sugar, microfilariae of O. volvulus and Acanthocheilonema perstans, particles of grit, and occasionally pollen grains. Flies bite no more than once in 2 or 3 days when the ovaries are developlng. They bite under diverse conditions but less in thick herbage than in the open. Few flies bite in moderately dark buildings. Biting begins before sunrise, lasts until after dusk, increases in the afternoon. One femalc can lay over 500 eggs. 15 parasites other than O. volvulus were found: 5 Protozoa, 6 nematodes, 1 hymenopterous planidium larva, 2 mites and an unidentified body, the common ones being a sp. of Mermis and the planidium. Human onchocerciasis occurs along the middle reaches of southern rivers before they reach the great swamps. It is much less widespread than S. damnosum which occurs without the disease in the n. Sudan and on s. streams. The infected area, although large, is relatively unimportant and unproductive; no towns are seriously affected. Reported incidence of blindness ranges from about 1% to 10% of the population. S. damnosum is considered to be the sole vector. At Mvolo during the rains the. avg. infection rate of developlng larvae in the fly was 12%. Highest infection rate observed was 36% with a head infection of 8.5%. Infected flies were found as far from the River Sue as 33 km. Transmission occurs chiefly in the rainy season, for then the fly is widely distributed and the infective stage of O. volvulus is common. Number of microfilariae ingested is considerably greater than that of larvae which complete development. Most microfilariae become enclosed by the peritrophic membrane and remain there until death. Some remain in the tubular part of the mid-gut when the membrane is forming, and apparently a few pass into the peritrophic space, penetrate the eplthelium of the expanding part of the mid-gut and enter the thoracic muscles. Practical control measures are unknown; for protection the use of slightly darkened buildings, protective clothing, and the repellent dimethyl phthalate are suggested.