Carboxylic acids that drive mosquito attraction to humans activate ionotropic receptors.

The mosquito, Aedes aegypti, is highly anthropophilic and transmits debilitating arboviruses within human populations and between humans and non-human primates. Female mosquitoes are attracted to sources of blood by responding to odor plumes that are emitted by their preferred hosts. Acidic volatile compounds, including carboxylic acids, represent particularly salient odors driving this attraction. Importantly, carboxylic acids are major constituents of human sweat and volatiles generated by skin microbes. As such, they are likely to impact human host preference, a dominant factor in disease transmission cycles. A more complete understanding of mosquito host attraction will necessitate the elucidation of molecular mechanisms of volatile odor detection that function in peripheral sensory neurons. Recent studies have shown that members of the variant ionotropic glutamate receptor gene family are necessary for physiological and behavioral responses to acidic volatiles in Aedes. In this study, we have identified a subfamily of variant ionotropic receptors that share sequence homology across several important vector species and are likely to be activated by carboxylic acids. Moreover, we demonstrate that selected members of this subfamily are activated by short-chain carboxylic acids in a heterologous cell expression system. Our results are consistent with the hypothesis that members of this receptor class underlie acidic volatile sensitivity in vector mosquitoes and provide a frame of reference for future development of novel mosquito attractant and repellent technologies.

Training Students as Navigators for Patients Experiencing Homelessness.

Background and Objectives: Despite the significant effects of homelessness on health, medical and health professions students rarely receive formal education in caring for individuals experiencing homelessness. We describe the implementation and evaluation of a novel student-run Patient Navigator Program (PNP) and its prerequisite elective that trains students in patient navigation principles specific to homelessness in the local community. METHODS: We analyzed pre- and postsurvey matched responses from students immediately before and after course completion. The survey utilizes the externally-validated instruments Health Professional Attitudes Toward the Homeless Inventory (HPATHI) and the Student-Run Free Clinic Project (SRFCP) survey. We examined differences using paired t tests and Wilcoxon signed-rank tests. Students also completed separate end-of-curriculum evaluation forms assessing satisfaction with the course. RESULTS: After completing the elective, students (n=45) demonstrated improvement in self-assessed attitude towards individuals experiencing homelessness (P=.03), specifically an increase in reported social advocacy (P<.001); and an increase in self-perceived knowledge about (P<.001), efficacy in working with (P=.01), and skills in caring for (P<.001) underserved groups. The elective also received high student satisfaction ratings. CONCLUSIONS: Formal education in patient navigation and caring for individuals experiencing homelessness improves self-assessed preparedness of future health care providers in serving homeless and underserved populations.