Parasitary Biology Post-Graduate Program, Biosciences Center, Federal University of Rio Grande Do Norte, Av. Senador Salgado Filho, 3000, Natal, Candelária, RN 59.072-970, Brazil.
IMNG - Innovation in Micro and Nanotechnologies Group, Center of Technology, Federal University of Rio Grande Do Norte - UFRN, Natal, Rio Grande do Norte, Brazil.
Parasitol Res. 2022 Sep;121(9):2673-2681. doi: 10.1007/s00436-022-07595-4. Epub 2022 Jul 12.
The use of repellents is considered an alternative against biting insects, including Lutzomyia longipalpis (Diptera: Psychodidae), the main vector of the protozoan Leishmania infantum, visceral leishmaniasis's (VL) etiologic agent in the Americas. This study aimed to evaluate the repellent efficacy of icaridin nanostructured solution applied on cotton knitting fabric against L. longipalpis. Arm-in-cage tests were performed in eight volunteers at different concentrations (5%, 10%, 25%, and 50%), using L. longipalpis (n = 30). The bioassay was performed in 1, 24, 48, 72, 96, 120, and 144 h after impregnation and one test after washing the fabrics with icaridin. The total repellency rate (%R) > 95% was used as a reference to define a minimum effective concentration (MEC). The results revealed that the insects' landing mean decreased significantly in different icaridin concentrations, compared with the control tests (p < 0.05) and the 25% and 50% concentrations compared to lower concentration (5%) (p < 0.05). The higher concentrations (25% and 50%) provided longer complete protection times (CPTs) with 120 and 144 h of protection, respectively and the %R of 100% for 72 and 96 h after impregnation, respectively. The 25% was the MEC (%R Total = 98.18%). Our results indicate, for the first time, that icaridin nanostructured solution applied on cotton knitting fabric proved to be an efficient repellent against L. longipalpis with the presence of repellent action even after washing. The concentration of 25% showed better efficiency and may become an efficient method for L. longipalpis biting control.
驱避剂的使用被认为是一种对抗吸血昆虫的替代方法，包括长角血蜱（双翅目：丽蝇科），这是美洲内脏利什曼原虫的主要载体，内脏利什曼病的病原体。本研究旨在评估纳米结构伊卡瑞丁溶液涂在棉针织织物上对长角血蜱的驱避效果。在不同浓度（5%、10%、25%和 50%）下，在 8 名志愿者的手臂-笼试验中，使用长角血蜱（n=30）进行了生物测定。在浸渍后 1、24、48、72、96、120 和 144 小时以及用伊卡瑞丁洗涤织物后进行了一次测试。将总驱避率（%R）>95%作为定义最小有效浓度（MEC）的参考。结果表明，与对照试验相比（p<0.05），不同伊卡瑞丁浓度下昆虫的着陆平均值显著降低，与较低浓度（5%）相比，25%和 50%浓度也显著降低（p<0.05）。较高浓度（25%和 50%）分别提供了长达 120 和 144 小时的完全保护时间（CPT），浸渍后 72 和 96 小时的%R分别为 100%。25%是 MEC（%R 总=98.18%）。我们的结果首次表明，纳米结构伊卡瑞丁溶液涂在棉针织织物上对长角血蜱具有高效驱避作用，即使在洗涤后仍具有驱避作用。25%的浓度表现出更好的效率，可能成为控制长角血蜱叮咬的有效方法。
