The efficacy of novel repellents against key arthropod vectors in Southeast Asia

Arthropod-borne diseases such as malaria, dengue fever, chikungunya, Zika, tick-borne diseases and scrub typhus have been major health threats to military personnel deployed in disease endemic countries. These diseases severely reduce the fighting capacity of the troops and cause suspension or cancellation of many military operations. In the absence of vaccines or effective prophylactic drugs, personal protective measures especially repellents are the most effective and primary means of preventing vector-borne diseases for the Warfighter. Currently, DEET and picaridin are used at very high concentrations by military and support personnel. Although these two repellents have been proven for their efficacy at repelling multiple species of disease vectors, safe usage of these repellents at effective concentrations is still a great concern due to potential adverse reactions causing skin irritation and rash on the individual. Finding additional repellents and/or alternatives to DEET and picaridin to protect Soldiers from biting arthropods is crucial. In this research, we aim to identify a single-long-lasting repellent product that is fully effective against the multiple arthropod vectors which are critical threats to military operations in INDOPACOM. The investigation will test the hypothesis that the repellency effects of novel repellents are comparable to DEET and picaridin for repelling a spectrum of Southeast Asian disease vectors including Anopheles and Aedes mosquitoes, Haemaphysalis ticks, and Leptotrombidium chigger mites under laboratory, semi-field, and field conditions in Thailand. Findings from this research may potentially complement other ongoing efforts to improve vector control and prevent disease transmission.