Anopheles gambiae, the major malaria mosquito in sub-Saharan Africa, feed largely indoors at night. Raising a house off the ground with no barriers underneath reduces mosquito-house entry. This experiment tested whether walling off the space under an elevated hut affects mosquito-hut entry. Four inhabited experimental huts, each of which could be moved up and down, were used in rural Gambia. Nightly collections of mosquitoes were made using light traps and temperature and carbon dioxide levels monitored indoors and outdoors using loggers. Each night, a reference hut was kept at ground level and three huts raised 2 m above the ground; with the space under the hut left open, walled with air-permeable walls or solid walls. Treatments were rotated every four nights using a randomized block design. The experiment was conducted for 32 nights. Primary measurements were mosquito numbers and indoor temperature in each hut. A total of 1,259 female Anopheles gambiae sensu lato were collected in the hut at ground level, 655 in the hut with an open ground floor, 981 in the hut with air-permeable walls underneath and 873 in the hut with solid walls underneath. Multivariate analysis, adjusting for confounders, showed that a raised hut open underneath had 53% fewer mosquitoes (95% CI 47–58%), those with air-permeable walls underneath 24% fewer (95% CI 9–36%) and huts with solid walls underneath 31% fewer (95% CI 24–37%) compared with a hut on the ground. Similar results were found for Mansonia spp. and total number of female mosquitoes, but not for Culex mosquitoes where hut entry was unaffected by height or barriers. Indoor temperature and carbon dioxide levels were similar in all huts. Raising a house 2 m from the ground reduces the entry of An. gambiae and Mansonia mosquitoes, but not Culex species. The protective effect of height is reduced if the space underneath the hut is walled off.

中文翻译：

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高架房屋下的物理屏障对蚊子进入的影响：冈比亚农村的一项实验研究

冈比亚按蚊是撒哈拉以南非洲地区的主要疟蚊，主要在夜间在室内进食。将房屋抬离地面且下方没有障碍物可以减少蚊子进入房屋。该实验测试了用墙壁隔离高架小屋下方的空间是否会影响蚊子进入小屋。在冈比亚农村使用了四个有人居住的实验小屋，每个小屋都可以上下移动。每晚使用捕光器收集蚊子，并使用记录仪监测室内和室外的温度和二氧化碳水平。每天晚上，在地面上保留一个参考小屋，并在距地面 2 m 的地方放置三个小屋；小屋下方的空间保持开放，用透气墙或实心墙围起来。采用随机区组设计，每四晚轮换一次治疗。实验进行了32个晚上。主要测量数据是每个小屋的蚊子数量和室内温度。地面小屋共采集雌性冈比亚按蚊 1,259 只，其中底层开放小屋 655 只，下方透气墙小屋 981 只，下方实心墙小屋 873 只。调整混杂因素后的多变量分析表明，下方开放的高架小屋的蚊子数量减少了 53%（95% CI 47-58%），下方有透气墙壁的蚊子数量减少了 24%（95% CI 9-36%），而小屋与地面上的小屋相比，下面有实心墙的空间减少了 31% (95% CI 24-37%)。对于曼索尼亚属 (Mansonia spp) 也发现了类似的结果。和雌性蚊子总数，但不适用于小屋入口不受高度或障碍物影响的库蚊。所有小屋的室内温度和二氧化碳水平相似。将房屋抬高 2 m 可以减少 An 的进入。冈比亚蚊子和曼索尼亚蚊子，但不是库蚊种。如果小屋下方的空间被围起来，高度的保护作用就会降低。