Vector Control Product Testing Unit, Department of Environmental Health and Ecological Science, Ifakara Health Institute, P.O. Box 74, Bagamoyo, Tanzania.
Swiss Tropical & Public Health Institute, Socinstrasse, 57, 4002, Basel, Switzerland.
Malar J. 2021 Jan 6;20(1):12. doi: 10.1186/s12936-020-03461-9.
N,N-Diethyl-3-methylbenzamide (DEET) topical mosquito repellents are effective personal protection tools. However, DEET-based repellents tend to have low consumer acceptability because they are cosmetically unappealing. More attractive formulations are needed to encourage regular user compliance. This study evaluated the protective efficacy and protection duration of a new topical repellent ointment containing 15% DEET, MAÏA compared to 20% DEET in ethanol using malaria and dengue mosquito vectors in Bagamoyo Tanzania.
Fully balanced 3 × 3 Latin square design studies were conducted in large semi-field chambers using laboratory strains of Anopheles gambiae sensu stricto, Anopheles arabiensis and Aedes aegypti. Human volunteers applied either MAÏA ointment, 20% DEET or ethanol to their lower limbs 6 h before the start of tests. Approximately 100 mosquitoes per strain per replicate were released inside each chamber, with 25 mosquitoes released at regular intervals during the collection period to maintain adequate biting pressure throughout the test. Volunteers recaptured mosquitoes landing on their lower limbs for 6 h over a period of 6 to 12-h post-application of repellents. Data analysis was conducted using mixed-effects logistic regression.
The protective efficacy of MAÏA and 20% DEET was not statistically different for each of the mosquito strains: 95.9% vs. 97.4% against An. gambiae (OR = 1.53 [95% CI 0.93-2.51] p = 0.091); 96.8% vs 97.2% against An. arabiensis (OR = 1.08 [95% CI 0.66-1.77] p = 0.757); 93.1% vs 94.6% against Ae. aegypti (OR = 0.76 [95% CI 0.20-2.80] p = 0.675). Average complete protection time (CPT) in minutes of MAÏA and that of DEET was similar for each of the mosquito strains: 571.6 min (95% CI 558.3-584.8) vs 575.0 min (95% CI 562.1-587.9) against An. gambiae; 585.6 min (95% CI 571.4-599.8) vs 580.9 min (95% CI 571.1-590.7) against An. arabiensis; 444.1 min (95% CI 401.8-486.5) vs 436.9 min (95% CI 405.2-468.5) against Ae. aegypti.
MAÏA repellent ointment provides complete protection for 9 h against both An. gambiae and An. arabiensis, and 7 h against Ae. aegypti similar to 20% DEET (in ethanol). MAÏA repellent ointment can be recommended as a tool for prevention against outdoor biting mosquitoes in tropical locations where the majority of the people spend an ample time outdoor before going to bed.
N,N-二乙基-3-甲基苯甲酰胺（DEET）的驱虫剂是有效的个人防护工具。然而，基于 DEET 的驱虫剂往往因为其外观不美观而导致消费者接受度低。需要更有吸引力的配方来鼓励消费者定期使用。本研究评估了一种新的驱虫软膏 MAÏA（含 15%DEET）和 20%DEET 在乙醇中的保护效果和保护时间，使用疟疾和登革热媒介蚊子在坦桑尼亚 Bagamoyo 进行测试。
使用实验室饲养的冈比亚按蚊、阿拉伯按蚊和埃及伊蚊，在大型半野外室中进行完全平衡的 3×3 拉丁方设计研究。志愿者在开始测试前 6 小时将 MAÏA 软膏、20%DEET 或乙醇涂抹在下肢。每间房内每只蚊子释放约 100 只，在收集期间每隔 25 分钟释放一次，以在整个测试过程中保持足够的叮咬压力。志愿者在涂抹驱虫剂后 6 至 12 小时内，对落在下肢上的蚊子进行 6 小时的捕获。数据分析采用混合效应逻辑回归。
MAÏA 和 20%DEET 对每种蚊子的保护效果无统计学差异：对冈比亚按蚊的保护率分别为 95.9%和 97.4%（OR=1.53 [95%CI 0.93-2.51]，p=0.091）；对阿拉伯按蚊的保护率分别为 96.8%和 97.2%（OR=1.08 [95%CI 0.66-1.77]，p=0.757）；对埃及伊蚊的保护率分别为 93.1%和 94.6%（OR=0.76 [95%CI 0.20-2.80]，p=0.675）。MAÏA 和 DEET 的平均完全保护时间（CPT）分钟数在每种蚊子中相似：对冈比亚按蚊分别为 571.6 分钟（95%CI 558.3-584.8）和 575.0 分钟（95%CI 562.1-587.9）；对阿拉伯按蚊分别为 585.6 分钟（95%CI 571.4-599.8）和 580.9 分钟（95%CI 571.1-590.7）；对埃及伊蚊分别为 444.1 分钟（95%CI 401.8-486.5）和 436.9 分钟（95%CI 405.2-468.5）。
MAÏA 驱虫软膏可提供 9 小时对冈比亚按蚊和阿拉伯按蚊的完全保护，对埃及伊蚊的完全保护时间为 7 小时，与 20%DEET（乙醇）相似。MAÏA 驱虫软膏可推荐用于预防热带地区户外叮咬蚊子，因为那里的大多数人在睡前会在户外度过大量时间。
