Abundance, resting and blood-meal preferences of Aedes aegypti in Ouagadougou, Burkina Faso

Abstract

Burkina Faso has experienced a re-emergence of dengue in recent years, with the majority of cases occurring in Ouagadougou. Effective control of the main vector Aedes aegypti, during outbreaks, requires a particularly better understanding of its behaviour and ecology. The study aims to assess the abundance, resting preferences and blood meal of Aedes aegypti from Ouagadougou, A total of 60 concessions in the districts of Bogodogo and Nongremasson were visited monthly from August to November 2021 for adult collection. Adults were collected indoors and outdoors. The origin of the blood meal in Aedes aegypti was determined by multiplex PCR targeting cytochrome b. A total of 671 Aedes aegypti individuals were collected, representing 5.35% of the total mosquitoes collected. Analysis of the resting preferences revealed a highly significant asymmetrical distribution between indoor and outdoor collected mosquitoes (p < 0.001). Only 24.1% (n = 162) were collected indoors, compared with 75.9% (n = 509) outdoors, representing an indoor/outdoor ratio of 0.32. From the 44 samples successfully identified, human blood was the most frequent meal source, 84.1% (37/44), and 11.36% (5/44) from animals, indicating a strong anthropophilic behaviour of Aedes aegypti in the city of Ouagadougou. However, a proportion of mosquitoes, 4.7% had mixed blood meals, indicating trophic opportunism. This resting and blood-feeding behaviour has important implications for disease transmission and vector control. Strategy based solely on indoor insecticide spraying may have limited effectiveness. Integrated approaches that target both outdoor and indoor resting sites and are therefore more likely to achieve a significant impact.