Mosquitoes genus Aedes are the most important arthropod disease vector. Dengue Virus (DENV) and Chikungunya Virus (CHIKV) are the main arboviruses distributed in the world. Based on entomo-virological surveillance, appropriating public health strategies can be addressed to contain cases and control outbreaks. This study aims to show the potential performance of two new molecular methods for detecting DENV serotypes and CHIKV in mosquitoes. Mosquitoes were collected in urban areas and sylvatic areas between July to August 2023, DENV and CHIKV were screened using new multiplex RT-PCR and RT-q PCR. A total of 2150 mosquitoes were trapped including 976 Aedes (959 Ae. egypti, 6 Ae. furcifer and 11 Ae. Vittatus) and 1174 Culex from 39 pools of a maximum of 30 mosquitoes each, tested by molecular screening, 7.7% (3/39) were positive for DENV, DENV-1 was detected in one pool (1/3), and DENV-3 in two pools (2/3). All the pools were negative for CHIKV. The overall minimum infection rate (MIR) of DENV in this study was 3.07 (95% CI: 2.24 —19.86). This study shows the usefulness of our new molecular tools in DENV serotypes and CHIKV surveillance.

Targeting genes involved in sexual determinism for vector or pest control purpose, requires a better understanding of their polymorphism in natural populations in order to ensure a rapid spread of the construct. By using genomic data from An. gambiae s.l., we analyzed the genetic variation and the conservation score of the fru gene in 18 natural populations across Africa. A total of 34339 SNPs were identified including 3.11% non-synonymous segregating sites. Overall, the nucleotide diversity was low and the Tajima's D neutrality test was negative indicating an excess of low frequency SNPs in the fru gene. The allelic frequencies of the non-synonymous SNPs were low (freq < 0.26) except two SNPs identified at high frequencies (freq > 0.8) in the Zinc-finger A and B protein domains. The conservation score was variable throughout the fru gene with maximum values in the exonic compared to the intronic regions. These results showed a low genetic variation in overall the exonic regions especially the male sex-specific exon and the BTB-exon 1 of the fru gene. These findings are crucial for the development of a gene drive construct targeting the fru gene that can rapidly spread without encountering resistance in wild populations.