Division of Livestock and Human Diseases Vector Control, Mosquito section, Tropical Pesticides Research Institute, P.O.BOX 3024, Arusha, Tanzania.
Parasit Vectors. 2012 Sep 5;5:189. doi: 10.1186/1756-3305-5-189.
The reduction of malaria parasite transmission by preventing human-vector contact is critical in lowering disease transmission and its outcomes. This underscores the need for effective and long lasting arthropod/insect repellents. Despite the reduction in malaria transmission and outcomes in Tanzania, personal protection against mosquito bites is still not well investigated. This study sought to determine the efficacy of menthol propylene glycol carbonate (MR08), Ocimum suave as compared to the gold standard repellent N, N-diethyl-methylbenzamide (DEET), either as a single dose or in combination (blend), both in the laboratory and in the field against Anopheles gambiae s.l and Culex quinquefasciatus.
In the laboratory evaluations, repellents were applied on one arm while the other arm of the same individual was treated with a base cream. Each arm was separately exposed in cages with unfed female mosquitoes. Repellents were evaluated either as a single dose or as a blend. Efficacy of each repellent was determined by the number of mosquitoes that landed and fed on treated arms as compared to the control or among them. In the field, evaluations were performed by human landing catches at hourly intervals from 18:00 hr to 01:00 hr.
A total of 2,442 mosquitoes were collected during field evaluations, of which 2,376 (97.30%) were An. gambiae s.l while 66 (2.70%) were Cx. quinquefaciatus. MR08 and DEET had comparatively similar protective efficacy ranging from 92% to 100 for both single compound and blends. These findings indicate that MR08 has a similar protective efficacy as DEET for personal protection outside bed nets when used singly and in blends. Because of the personal protection provided by MR08, DEET and blends as topical applicants in laboratory and field situations, these findings suggest that, these repellents could be used efficiently in the community to complement existing tools. Overall, Cx. quinquefasciatus were significantly prevented from blood feeding compared to An. gambiae s.l.
The incorporation of these topical repellents for protection against insect bites can be of additional value in the absence or presence of IRS and ITNs coverage. However, a combination of both the physical (bed nets) and the repellent should be used in an integrated manner for maximum protection, especially before going to bed. Additional research is needed to develop repellents with longer duration of protection.
通过防止人与媒介接触来减少疟原虫传播，对于降低疾病传播及其结果至关重要。这凸显了对有效且持久的节肢动物/昆虫驱避剂的需求。尽管坦桑尼亚的疟疾传播和结果有所减少，但对防蚊叮咬的个人保护措施仍未得到充分研究。本研究旨在确定薄荷醇丙二醇碳酸盐（MR08）、甜罗勒与标准驱避剂 N，N-二乙基-间甲苯酰胺（DEET）相比，无论是作为单一剂量还是混合物（混合），在实验室和现场对冈比亚按蚊和库蚊的驱避效果。
在实验室评估中，将驱避剂涂在一只手臂上，而同一人的另一只手臂则用基础乳膏处理。将每只手臂分别暴露在带有未进食的雌性蚊子的笼子中。驱避剂要么作为单一剂量，要么作为混合物进行评估。通过与对照或其中之一相比，落在处理过的手臂上并进食的蚊子数量来确定每种驱避剂的功效。在现场，每小时 18:00 到 01:00 进行人类降落捕捉评估。
在现场评估中，共收集了 2442 只蚊子，其中 2376 只（97.30%）为冈比亚按蚊，66 只（2.70%）为库蚊。MR08 和 DEET 的单一化合物和混合物的保护效果相似，范围从 92%到 100%。这些发现表明，MR08 作为单独使用和混合物时，在蚊帐外对个人的保护具有与 DEET 相似的效果。由于 MR08、DEET 和混合物在实验室和现场情况下作为局部应用提供了个人保护，这些发现表明这些驱避剂可以有效地在社区中使用，以补充现有工具。总体而言，与冈比亚按蚊相比，库蚊明显被阻止了吸血。
在缺乏 IRS 和 ITN 覆盖率或存在 IRS 和 ITN 覆盖率的情况下，将这些局部驱避剂用于防止昆虫叮咬可以增加额外的价值。然而，应将物理（蚊帐）和驱避剂结合起来以获得最大的保护，尤其是在睡前。需要进一步研究来开发具有更长保护期的驱避剂。
