Beier J C, Perkins P V, Onyango F K, Gargan T P, Oster C N, Whitmire R E, Koech D K, Roberts C R
Kenya Medical Research Institute, Nairobi.
J Med Entomol. 1990 Jul;27(4):570-7. doi: 10.1093/jmedent/27.4.570.
Malaria transmission was studied for 33 mo in the villages of Kisian and Saradidi in western Kenya in preparation for field trials of malaria vaccines. Abundance estimates of Anopheles gambiae Giles sensu lato and Anopheles funestus Giles, which constituted over 99% of 26,645 anophelines collected, were compared for all-night biting collections inside houses, outdoors, and in tents. The overall numbers of Anopheles per man-night were 2.3 times greater in Kisian than in Saradidi. For the three types of collections, mean sporozoite rates by dissection ranged from 2.2 to 5.4% for 13,072 Anopheles in Kisian and from 9.9 to 13.6% for 7,058 Anopheles in Saradidi; greater than 90% of the infections were Plasmodium falciparum, either alone or mixed with P. malariae or P. ovale. Heaviest transmission from April to July coincided with the end of the long rainy season. Entomological inoculation rates (EIR) averaged 0.82 infective bites per man per night inside houses in Kisian and 0.65 in Saradidi. Outdoors, EIRs averaged 0.09 in Kisian and 0.52 in Saradidi. In tents, which were evaluated to identify methods for exposing nonindigenous volunteers during vaccine efficacy trials, EIRs were 3.3 and 2.5 times less than inside houses for Kisian (EIR = 0.25) and Saradidi (EIR = 0.26), respectively. Exposure in tents averaged one infective bite every 4.0 d in Kisian and every 3.8 d in Saradidi. The use of tents in vaccine efficacy trials should provide adequate exposure for nonindigenous volunteers. Malaria vaccine trials could be conducted efficiently in western Kenya, with timing dependent upon the intensity of transmission required by vaccine trial objectives.
为准备疟疾疫苗的现场试验，在肯尼亚西部的基西安村和萨拉迪迪村对疟疾传播情况进行了33个月的研究。在房屋内、户外和帐篷内进行通宵叮咬采集，比较了构成所采集的26,645只按蚊中99%以上的冈比亚按蚊复合组和险恶按蚊的数量估计值。基西安村每人每晚的按蚊总数比萨拉迪迪村多2.3倍。对于这三种采集类型，在基西安村，对13,072只按蚊进行解剖后的平均子孢子率为2.2%至5.4%，在萨拉迪迪村，对7,058只按蚊进行解剖后的平均子孢子率为9.9%至13.6%；超过90%的感染为恶性疟原虫，单独感染或与间日疟原虫或卵形疟原虫混合感染。4月至7月传播最严重，这与漫长雨季的结束相吻合。基西安村房屋内的昆虫接种率（EIR）平均为每人每晚0.82次感染性叮咬，萨拉迪迪村为0.65次。在户外，基西安村的EIR平均为0.09，萨拉迪迪村为0.52。在帐篷内（帐篷用于确定在疫苗效力试验中让非本地志愿者暴露的方法），基西安村（EIR = 0.25）和萨拉迪迪村（EIR = 0.26）的EIR分别比房屋内低3.3倍和2.5倍。在基西安村，帐篷内的暴露平均每4.0天有一次感染性叮咬，在萨拉迪迪村为每3.8天一次。在疫苗效力试验中使用帐篷应为非本地志愿者提供足够的暴露。疟疾疫苗试验可以在肯尼亚西部高效进行，时间安排取决于疫苗试验目标所需的传播强度。
