MAÏA® Topical Repellent Ointment Provides Long-Lasting Protection Against Anopheles Gambiae s.s., Anopheles Arabiensis and Aedes Aegypti Under Semi-Field Conditions in Tanzania

Abstract

Background: N,N-Diethyl-3-methylbenzamide (DEET) topical mosquito repellents are effective personal protection tools. However, DEET repellents tend to have low consumer acceptability because they are cosmetically unappealing. More attractive formulations are needed to encourage regular compliance. This study evaluated the protective efficacy and duration of protection of a new topical repellent ointment, MAÏA® compared to 20% DEET in ethanol using malaria and dengue mosquito vectors in Tanzania.Methods: Fully balanced 3x3 Latin square design studies were conducted in large semi-field chambers using laboratory strains of Anopheles gambiae s.s, Anopheles arabiensis and Aedes aegypti. Human volunteers applied either MAÏA® ointment, 20% DEET or ethanol to their lower limbs six hours before the start of tests. Approximately 100 mosquitoes per strain per replicate were released inside each chamber, with 25 mosquitoes released at regular intervals during the collection period to maintain adequate biting pressure throughout the test. Volunteers recaptured mosquitoes landing on their lower limbs for six hours over a period of six to 12-hours post-application of repellents. Data analysis was conducted using mixed-effects logistic regression.Results: The protective efficacy of MAÏA® and 20% DEET was not different for each of the mosquito strains: 95.9% vs 97.4% against An. gambiae (OR=1.53 [95% CI: 0.93–2.51] p=0.091); 96.8% vs 97.2% against An. arabiensis (OR =1.08 [95% CI: 0.66 –1.77] P=0.757); 93.1% vs 94.6% against Ae. aegypti (OR=0.76 [95% CI: 0.20-2.80] p=0.675). Average complete protection time (CPT) of MAÏA® and that of DEET was similar for each of the mosquito strains: 571.6 minutes (95% CI: 558.3-584.8) vs 575.0 minutes (95% CI: 562.1-587.9) against An. gambiae; 585.6 minutes (95% CI: 571.4-599.8) vs 580.9 minutes (95% CI: 571.1-590.7) against An. arabiensis; 444.1 minutes (95% CI: 401.8-486.5) vs 436.9 minutes (95% CI: 405.2-468.5) against Ae. aegypti.Conclusions: MAÏA® repellent ointment provides complete protection for 9 hours against both An. gambiae and An. arabiensis, and 7 hours against Ae. aegypti similar to 20% DEET (in ethanol). MAÏA® repellent ointment can be recommended as a tool for prevention of outdoor biting mosquitoes in tropical locations with a suggested reapplication time of 6 hours.