Influence of the host sex on the duration of protection by topical repellents against mosquitoes and ticks

Abstract Vector-borne diseases pose significant public health challenges globally, necessitating effective personal protection strategies against insect bites. Topical repellents have been widely used to mitigate these risks, yet their efficacy is affected by several factors, including the biological characteristics of users. Typically, studies assessing the efficacy of topical repellents require a balanced representation of participants, with a sample size of at least 10 individuals, evenly divided between females and males, to simulate the population. This study aims to evaluate the correlation between the sex of volunteers and the protection duration provided by DEET and Icaridin against four mosquito species ( Culex pipiens, Anopheles gambiae, Aedes albopictus, Culex quinquefasciatus ), and the tick species Ixodes ricinus . Fourteen separate trials were conducted, and no significant differences in complete protection time (CPT) were observed between male and female participants. These findings suggest that the human host sex may not influence the efficacy of topical repellents significantly. Future research should focus on a more diverse range of demographic and biological characteristics to help optimise usage guidelines, contributing to better protection against vector-borne diseases in different populations and settings.